Fundamentals of Materials Science and Engineering An Integrated Approach, 5th Edition William D. Cal

TEST BANK (reserved questions and solutions

Reserve Questions and Problems

CHAPTER 1 INTRODUCTION Reserve Problem 01a (question pool) Materials Science and Engineering is the study of material behavior & performance and how this is simultaneously related to structure, properties, and processing. Which of the following is the best example of a material property? (a) Density (b) Annealing (c) Forging (d) Single-crystal (e) Crystalline

Reserve Problem 02a (question pool) Materials Science and Engineering is the study of material behavior & performance and how this is simultaneously related to structure, properties, and processing. Which of the following is the best example of material processing? (a) Extrusion (b) Crystalline (c) Amorphous (d) Glassy (e) Elastic Modulus

Reserve Problem 03a (question pool)

simultaneously related to structure, properties, and processing. Which of the following is the best example of material structure? (a) Single-phase (b) Elastic Modulus (c) Sintering (d) Magnetic Permeability (e) Brittle

Reserve Problem 04a (question pool) Which class of material is generally associated with the highest density values at room temperature? (a) Composites (b) Ceramics (c) Metals (d) Polymers

Reserve Problem 05a (question pool) By how many orders of magnitude (powers of ten, approximately) does density vary for metals? (a) 0.13 (b) 1.3 (c) 13 (d) 130

Materials Science and Engineering is the study of material behavior & performance and how this is

CHAPTER 2 ATOMIC STRUCTURE AND INTERATOMIC BONDING Reserve Question 01: Atomic mass

Reserve Question 02: Atomic nucleus

The atomic mass of an atom may be expressed as the sum of the masses of • Electrons • Neutrons • Protons Choose all that apply.

The nucleus of an atom contains • Electrons • Neutrons • Protons Choose all that apply.

• R-1

R-2 • Reserve Questions and Problems Reserve Question 03: Atomic number The atomic number of an electrically neutral atom is equal to the number of: • protons • electrons • neutrons Choose all that apply.

Reserve Problem 04 Hafnium has six naturally occurring isotopes: 0.16% of 174Hf, with an atomic weight of 173.940 amu; 5.26% of 176Hf, with an atomic weight of 175.941 amu; 18.60% of 177Hf, with an atomic weight of 176.943 amu; 27.28% of 178Hf, with an atomic weight of 177.944 amu; 13.62% of 179Hf, with an atomic weight of 178.946 amu; and 35.08% of 180Hf, with an atomic weight of 179.947 amu. Calculate the average atomic weight of Hf. Give your answer to three decimal places.

Reserve Problem 05 Bromium has two naturally occurring isotopes: 79Br, with an atomic weight of 78.918 amu, and 81Br, with an atomic weight of 80.916 amu. If the average atomic weight for Br is 79.903 amu, calculate the fraction-ofoccurrences of these two isotopes. Give your answer to three decimal places.

Fraction-of-occurrence for 79Br: ______ Fraction-of-occurrence for 81Br: ______

Reserve Problem 06: Electron configuration An element that has the electron configuration 1s22s22p6 has how many electrons? Enter numeric values only.

Reserve Problem 07: The four electron subshells M, K, L, N Which subshells are found in each of the following shells? (a) Electron subshells—M shell • s • p • d • f (b) Electron subshells—K shell • s • p • d • f

(c) Electron subshells—L shell • s • p • d • f (d) Electron subshells—N shell • s • p • d • f

Reserve Problem 08: The number of electrons in subshells M, K, L, N What is the maximum number of electrons that each of the following shells can contain? (a) M shell ______ electrons (b) K shell ______ electrons (c) L shell ______ electrons (d) N shell ______ electrons

Reserve Question 09: The electrons that occupy the outermost…

The electrons that occupy the outermost filled shell are called ______ electrons.

Reserve Question 10: When all the electrons in an atom occupy…

When all the electrons in an atom occupy the lowest possible energy states, the atom is said to be in its: • ground state • ionized state • cold state • regular state

Reserve Problem 11 How many p electrons at the outermost orbital do the Group VIIA elements have?

Reserve Problem 12 To what group in the periodic table would an element with atomic number 119 belong?

• Group 0 (or 18) • Group IA (or 1) • Group IIA (or 2) • Group VIIA (or 17)

Reserve Problem 13 Ideally speaking, bonds tend to form between two particles such that they are separated by a distance

Reserve Questions and Problems • R-3 where ______ net force is exerted on them, and their overall energy is ______. (a) a positive, maximized (b) a negative, maximized (c) a positive, minimized (d) a negative, minimized (e) zero, maximized (f) zero, minimized

Reserve Problem 17 ______ bonds are the only primary bonds that are directionally dependent. (a) Covalent (c) Ionic (b) Metallic (d) Van der Waals

Reserve Problem 18

Calculate the force of attraction (in N) between a cation with a valence of +2 and an anion with a valence of −3, the centers of which are separated by a distance of 8.6 nm.

______ bonds are responsible for binding atoms together within a molecule of propane, whereas ______ bonds bind separate propane molecules together in a condensed state (liquid or crystal). (a) Covalent, Ionic (b) Ionic, Covalent (c) Covalent, Metallic (d) Metallic, Covalent (e) Covalent, Van der Waals (f) Van der Waals, Covalent (g) Ionic, Van der Waals (h) Van der Waals, Ionic

Reserve Problem 16

Reserve Problem 19

______ bonding is similar to ionic bonding, except there are no high-electronegativity atoms present to accept any electrons that the present atoms are willing to donate. (a) Ionic (c) Metallic (b) Covalent (d) Hydrogen

Materials whose constituent particles are bound by which type of bond are generally expected to have the lowest melting temperatures? (a) Covalent (d) Van der Waals (b) Metallic (e) Hydrogen (c) Ionic

Reserve Problem 14: Attraction energy Calculate the energy of attraction between a cation with a valence of +2 and an anion with a valence of −2, the centers of which are separated by a distance of 3.7 nm.

Reserve Problem 15: Attraction force

Reserve Problem 20: Ionic character Using the figure below, calculate the percent ionic character of the interatomic bonds for the following materials: (a) CaCl2 (b) CsBr 0

IA 1

2

H

He

2.1 3

IIA

IIIA

IVA

VA

VIA

VIIA

4

5

6

7

8

9

– 10

Li

Be

B

C

N

O

F

Ne

1.0 11

1.5 12

2.0 13

2.5 14

3.0 15

3.5 16

4.0 17

– 18

Na

Mg

0.9 19

1.2 20

VIII IIIB

IVB

VB

VIB

VIIB

21

22

23

24

25

26

27

28

IB

IIB

29

30

Al

Si

P

S

Cl

Ar

1.5 31

1.8 32

2.1 33

2.5 34

3.0 35

– 36

Kr

K

Ca

Sc

Ti

V

Cr

Mn

Fe

Co

Ni

Cu

Zn

Ga

Ge

As

Se

Br

0.8

1.0

1.3

1.5

1.6

1.6

1.5

1.8

1.8

1.8

1.9

1.6

1.6

1.8

2.0

2.4

2.8

–

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

53

54

Rb

Sr

Y

Zr

Nb

Mo

Tc

Ru

Rh

Pd

Ag

Cd

In

Sn

Sb

Te

I

Xe

0.8 55

1.0 56

1.2 57–71

1.4 72

1.6 73

1.8 74

1.9 75

2.2 76

2.2 77

2.2 78

1.9 79

1.7 80

1.7 81

1.8 82

1.9 83

2.1 84

2.5 85

– 86

Cs

Ba

La–Lu

Hf

Ta

W

Re

Os

Ir

Pt

Au

Hg

Tl

Pb

Bi

Po

At

Rn

0.7 87

0.9 88

1.1–1.2 89–102

1.3

1.5

1.7

1.9

2.2

2.2

2.2

2.4

1.9

1.8

1.8

1.9

2.0

2.2

–

Fr

Ra

Ac–No

0.7

0.9

1.1–1.7

R-4 • Reserve Questions and Problems Reserve Problem 21 (a) Calculate %IC of the interatomic bonds for the intermetallic compound TiAl3.

(b) On the basis of this result, what type of interatomic bonding would you expect to be found in TiAl3?

• Van der Waals • metallic • ionic • covalent

CHAPTER 3 STRUCTURES OF METALS AND CERAMICS Reserve Problem 01a (question pool)

Reserve Problem 02a (question pool)

Which structure is most consistent with a polycrystalline structure?

Which structure is most consistent with an amorphous structure?

(a)

(a)

(b)

(b)

(c)

(c)

(d)

(d)

Reserve Questions and Problems • R-5 Reserve Problem 03

Reserve Problem 07a (question pool)

Which of the following microstructures is expected to be most similar to a single crystal in terms of structure and properties? Assume all of the options offer the same volumes and only consider grain boundaries as a crystalline defect for this question. (a) Textured polycrystal with about 10,000 grains

Which of the following partial lattices does not exhibit 6-fold symmetry? (a)

(b) Random polycrystal with about 1,000,000 grains (c) Random polycrystal with about 1,000,000,000 grains (d) Amorphous

Reserve Problem 04a (question pool) Which of the following is the primitive unit cell for the lattice that is depicted?

(b)

Reserve Problem 05a (question pool) Which of the following candidate unit cells is invalid? (c)

(d)

Reserve Problem 06a (question pool) Which of the following unit cells exhibits the highest symmetry?

R-6 • Reserve Questions and Problems Reserve Problem 08

Reserve Problem 09c-1 (question pool)

Using atomic weight, crystal structure, and atomic radius data tabulated inside the front cover, compute the theoretical densities of lead, chromium, copper, and cobalt, and then compare these values with the measured densities listed in this same table. The c/a ratio for cobalt is 1.623.

Which of the following options is consistent with the unit cell plane depicted below?

Reserve Problem 09a-1 (question pool) Which of the following options is consistent with the unit cell plane depicted below? (a) SC {100} (b) BCC {100} (c) FCC {100} (d) SC {110} (e) BCC {110} (f) FCC {110} (g) SC {111} (h) BCC {111} (i) FCC {111}

(a) SC {100} (b) BCC {100} (c) FCC {100} (d) SC {110} (e) BCC {110} (f) FCC {110} (g) SC {111} (h) BCC {111} (i) FCC {111}

Reserve Problem 09d-1 (question pool) Which of the following options is consistent with the unit cell plane depicted below?

Reserve Problem 09b-1 (question pool) Which of the following options is consistent with the unit cell plane depicted below?

(a) SC {100} (b) BCC {100} (c) FCC {100} (d) SC {110} (e) BCC {110}

(f) FCC {110} (g) SC {111} (h) BCC {111} (i) FCC {111}

(a) SC {100} (b) BCC {100} (c) FCC {100} (d) SC {110} (e) BCC {110} (f) FCC {110} (g) SC {111} (h) BCC {111} (i) FCC {111}

Reserve Questions and Problems • R-7 Reserve Problem 10a-1 (question pool)

Reserve Problem 10c-1 (question pool)

Which of the following options is consistent with the unit cell plane depicted below?

Which of the following options is consistent with the unit cell plane depicted below?

(a) SC {100} (b) BCC {100} (c) FCC {100} (d) SC {110} (e) BCC {110} (f) FCC {110} (g) SC {111} (h) BCC {111} (i) FCC {111}

(a) SC {100} (b) BCC {100} (c) FCC {100} (d) SC {110} (e) BCC {110} (f) FCC {110} (g) SC {111} (h) BCC {111} (i) FCC {111}

Reserve Problem 10b-1 (question pool)

Reserve Problem 10d-1 (question pool)

Which of the following options is consistent with the unit cell plane depicted below?

Which of the following options is consistent with the unit cell plane depicted below?

(a) SC {100} (b) BCC {100} (c) FCC {100} (d) SC {110} (e) BCC {110} (f) FCC {110} (g) SC {111} (h) BCC {111} (i) FCC {111}

(a) SC {100} (b) BCC {100} (c) FCC {100} (d) SC {110} (e) BCC {110} (f) FCC {110} (g) SC {111} (h) BCC {111} (i) FCC {111}

R-8 • Reserve Questions and Problems Reserve Problem 11a-1 (question pool)

Reserve Problem 11c-1 (question pool)

Which of the following options is consistent with the unit cell plane depicted below?

Which of the following options is consistent with the unit cell plane depicted below?

(a) SC {100} (b) BCC {100} (c) FCC {100} (d) SC {110} (e) BCC {110} (f) FCC {110} (g) SC {111} (h) BCC {111} (i) FCC {111}

Reserve Problem 11b-1 (question pool) Which of the following options is consistent with the unit cell plane depicted below?

(a) SC {100} (b) BCC {100} (c) FCC {100} (d) SC {110} (e) BCC {110} (f) FCC {110} (g) SC {111} (h) BCC {111} (i) FCC {111}

(a) SC {100} (b) BCC {100} (c) FCC {100} (d) SC {110} (e) BCC {110} (f) FCC {110} (g) SC {111} (h) BCC {111} (i) FCC {111}

Reserve Problem 11d-1 (question pool) Which of the following options is consistent with the unit cell plane depicted below?

(a) SC {100} (b) BCC {100} (c) FCC {100} (d) SC {110} (e) BCC {110} (f) FCC {110} (g) SC {111} (h) BCC {111} (i) FCC {111}

Reserve Questions and Problems • R-9 Reserve Problem 12a-1 (question pool)

Reserve Problem 12c-1 (question pool)

Which of the following options is consistent with the unit cell plane depicted below?

Which of the following options is consistent with the unit cell plane depicted below?

(a) SC {100} (b) BCC {100} (c) FCC {100} (d) SC {110} (e) BCC {110} (f) FCC {110} (g) SC {111} (h) BCC {111} (i) FCC {111}

(a) SC {100} (b) BCC {100} (c) FCC {100} (d) SC {110} (e) BCC {110} (f) FCC {110} (g) SC {111} (h) BCC {111} (i) FCC {111}

Reserve Problem 12b-1 (question pool)

Reserve Problem 12d-1 (question pool)

Which of the following options is consistent with the unit cell plane depicted below?

Which of the following options is consistent with the unit cell plane depicted below?

(a) SC {100} (b) BCC {100} (c) FCC {100} (d) SC {110} (e) BCC {110} (f) FCC {110} (g) SC {111} (h) BCC {111} (i) FCC {111}

(a) SC {100} (b) BCC {100} (c) FCC {100} (d) SC {110} (e) BCC {110} (f) FCC {110} (g) SC {111} (h) BCC {111} (i) FCC {111}

R-10 • Reserve Questions and Problems Reserve Problem 13a-1 (question pool)

Reserve Problem 13c-1 (question pool)

Which of the following options is consistent with the unit cell plane depicted below?

Which of the following options is consistent with the unit cell plane depicted below?

(a) SC {100} (b) BCC {100} (c) FCC {100} (d) SC {110} (e) BCC {110} (f) FCC {110} (g) SC {111} (h) BCC {111} (i) FCC {111}

(a) SC {100} (b) BCC {100} (c) FCC {100} (d) SC {110} (e) BCC {110} (f) FCC {110} (g) SC {111} (h) BCC {111} (i) FCC {111}

Reserve Problem 13b-1 (question pool)

Reserve Problem 13d-1 (question pool)

Which of the following options is consistent with the unit cell plane depicted below?

Which of the following options is consistent with the unit cell plane depicted below?

(a) SC {100} (b) BCC {100} (c) FCC {100} (d) SC {110} (e) BCC {110} (f) FCC {110} (g) SC {111} (h) BCC {111} (i) FCC {111}

(a) SC {100} (b) BCC {100} (c) FCC {100} (d) SC {110} (e) BCC {110} (f) FCC {110} (g) SC {111} (h) BCC {111} (i) FCC {111}

Reserve Questions and Problems • R-11 Reserve Problem 14a-1 (question pool)

Reserve Problem 14c-1 (question pool)

Which of the following options is consistent with the unit cell plane depicted below?

Which of the following options is consistent with the unit cell plane depicted below?

(a) SC {100} (b) BCC {100} (c) FCC {100} (d) SC {110} (e) BCC {110} (f) FCC {110} (g) SC {111} (h) BCC {111} (i) FCC {111}

(a) SC {100} (b) BCC {100} (c) FCC {100} (d) SC {110} (e) BCC {110} (f) FCC {110} (g) SC {111} (h) BCC {111} (i) FCC {111}

Reserve Problem 14b-1 (question pool)

Reserve Problem 14d-1 (question pool)

Which of the following options is consistent with the unit cell plane depicted below?

Which of the following options is consistent with the unit cell plane depicted below?

(a) SC {100} (b) BCC {100} (c) FCC {100} (d) SC {110} (e) BCC {110} (f) FCC {110} (g) SC {111} (h) BCC {111} (i) FCC {111}

(a) SC {100} (b) BCC {100} (c) FCC {100} (d) SC {110} (e) BCC {110} (f) FCC {110} (g) SC {111} (h) BCC {111} (i) FCC {111}

R-12 • Reserve Questions and Problems Reserve Problem 15a-1 (question pool)

Reserve Problem 15d-1 (question pool)

Which of the following options is consistent with the unit cell plane depicted below?

Which of the following options is consistent with the unit cell plane depicted below?

(a) SC {100} (b) SC {110} (c) SC {111}

(d) FCC {100} (e) FCC {110} (f) FCC {111}

Reserve Problem 15b-1 (question pool) Which of the following options is consistent with the unit cell plane depicted below?

(a) SC {100} (b) SC {110} (c) SC {111} (d) FCC {100} (e) FCC {110} (f) FCC {111}

Reserve Problem 16a-1 (question pool) Which of the following options is consistent with the unit cell plane depicted below?

(a) SC {100} (b) SC {110} (c) SC {111}

(d) FCC {100} (e) FCC {110} (f) FCC {111}

Reserve Problem 15c-1 (question pool) Which of the following options is consistent with the unit cell plane depicted below? (a) FCC {100} (b) FCC {110} (c) FCC {111} (d) SC {100} (e) SC {110} (f) SC {111} (a) SC {100} (b) SC {110} (c) SC {111}

(d) FCC {100} (e) FCC {110} (f) FCC {111}

Reserve Questions and Problems • R-13 Reserve Problem 16b-1 (question pool)

Reserve Problem 16d-1 (question pool)

Which of the following options is consistent with the unit cell plane depicted below?

Which of the following options is consistent with the unit cell plane depicted below?

(a) FCC {100} (b) FCC {110} (c) FCC {111} (d) SC {100} (e) SC {110} (f) SC {111}

Reserve Problem 16c-1 (question pool) Which of the following options is consistent with the unit cell plane depicted below?

(a) FCC {100} (b) FCC {110} (c) FCC {111}

(d) SC {100} (e) SC {110} (f) SC {111}

Reserve Problem 17a (question pool) Certain crystal structures are sometimes similar to other crystal structures in a variety of ways. This problem demonstrates one of the similarities that exists between two of the cubic crystal structures discussed in Chapter 3. Specifically, a family of planes in one of these crystal structures is equivalent to a family of planes in the other crystal structure.

For now, we are just considering how equal-sized spheres, but you may also consider this as atoms of the same element packing together to form two crystals, each of which exhibits one of these different crystal structures.

The figure below depicts a plane of atoms of radius R in some crystal. The plane intersects the atoms through their centers. Therefore, we do not see atoms above and below this plane. We just see the circular cross-sections of the atoms that lie within the plane.

(a) FCC {100} (b) FCC {110} (c) FCC {111} (d) SC {100} (e) SC {110} (f) SC {111}

R-14 • Reserve Questions and Problems If we consider only simple cubic (SC), body-centered cubic (BCC), and face-centered cubic (FCC) crystal structures as options, and we have no more information to rely on, what are the two possible identities for the plane shown above?

Select all that apply. (a) SC {100} (b) BCC {100} (c) FCC {100} (d) SC {110} (e) BCC {110} (f) FCC {110} (g) SC {111} (h) BCC {111} (i) FCC {111}

Reserve Problem 22: BCC unit cell volume If the atomic radius of a metal that has the bodycentered cubic crystal structure is 0.181 nm, calculate the volume of its unit cell.

Reserve Problem 23: FCC unit cell volume

Reserve Problem 18: Atomic radius–simple cubic For a metal that has the simple cubic crystal structure, calculate the atomic radius if the metal has a density of 2.05 g/cm3 and an atomic weight of 77.84 g/mol.

Reserve Problem 19: Cubic unit cell Some metal is known to have a cubic unit cell with an edge length of 0.437 nm. In addition, it has a density of 4.37 g/cm3 and an atomic weight of 54.85 g/mol.

Indicate the letter of the metal listed in the following table that has these characteristics.

Metal

Crystal Structure

Atomic Radius (nm)

A B C D

BCC FCC FCC HCP

0.219 0.309 0.155 0.125

Reserve Problem 20: Crystal Lengths III In terms of the atomic radius, R, determine the distance between the centers of adjacent atoms for the BCC crystal structure along the [110] direction.

4*R*

From the list below select all possible sets of indices for this plane. (a) (001) (b) (11–1) (c) (111) (d) (–1–1–1) (e) (101) (f) (100)

√2 √3

Reserve Question 21: Miller indices III Below is shown the atomic packing of a plane for the simple cubic crystal structure; atoms drawn to full size are represented by the circles.

If the atomic radius of a metal that has the facecentered cubic crystal structure is 0.123 nm, calculate the volume of its unit cell.

Reserve Problem 24: Hexagonal close-packed structure For the hexagonal close-packed crystal structure: (a) How many atoms are associated with the unit cell? (b) What is the coordination number? (c) What is the atomic packing factor?

Reserve Problem 25: Orthorhombic unit cell A hypothetical metal has an orthorhombic unit cell for which the a, b, and c lattice parameters are 0.472, 0.732, and 0.826 nm, respectively. (a) If there are 8 atoms per unit cell and the atomic packing factor is 0.549, then determine the atomic radius. (b) If the density is 6.04 g/cm3, then calculate the metal’s atomic weight.

Reserve Problem 26: Rhodium structure Rhodium has an atomic radius of 0.1345 nm, a density of 12.41 g/cm3 and an atomic weight of 102.91 g/mol.

What is rhodium’s crystal structure? (a) Simple cubic (b) BCC (c) FCC

Reserve Problem 27: Unit cell length A hypothetical metal has a cubic unit cell, a density of 6.79 g/cm3, a coordination number of 6, and an atomic weight of 78.57 g/mol. Calculate the unit cell edge length for this material.

Reserve Questions and Problems • R-15 Reserve Problem 28

Reserve Problem 34a (question pool)

Iron has a BCC crystal structure, an atomic radius of 0.124 nm, and an atomic weight of 55.85 g/mol.

Compute and compare its theoretical density with the experimental value found inside the front cover of the book.

Consider the ideal barium titanate (BaTiO3) structure. What is the coordination number of the Ti4+ ion in terms of surrounding O2– ions? (a) 1 (e) 5 (b) 2 (f) 6 (c) 3 (g) 7 (d) 4 (h) 8

Reserve Problem 29 Niobium (Nb) has a BCC crystal structure, an atomic radius of 0.143 nm and an atomic weight of 92.91 g/mol.

Calculate the theoretical density for Nb.

Reserve Problem 30 Rhenium has an HCP crystal structure, an atomic radius of 0.137 nm, and a c/a ratio of 1.615. Compute the volume of the unit cell for Re.

Reserve Problem 31 The unit cell for MgFe2O4 (MgO-Fe2O3) has cubic symmetry with a unit cell edge length of 0.836 nm. If the density of this material is 4.52 g/cm3, compute its atomic packing factor. For this computation, you will need to use ionic radii listed in Table 3.4.

Reserve Problem 35 Consider the ideal barium titanate (BaTiO3) structure. What is the coordination number of the Ba2+ ion in terms of surrounding Ti4+ ions? (a) 4 (d) 10 (b) 6 (e) 12 (c) 8

Reserve Problem 36 Which of the following options correctly depicts a {110} plane from a diamond cubic unit cell? (a)

Reserve Problem 32 For each statement below, choose the bonding type that best completes each phrase. (a) The crystal structures of ______ ceramics are constrained by bond angles associated with the locations of shared electrons within the material. (b) The coordination number of ______ ceramics are constrained by the relative sizes of the compound’s component species. (c) The crystal structures of ______ ceramics are constrained by the relative charges of the compound’s component species. (d) The crystal structures of ______ ceramics are constrained by ratio of the compound’s charged component species such that the structure maintains charge neutrality.

(b)

Reserve Problem 33 Consider the fluorite (CaF2) crystal structure. The coordination number of Ca2+ ions is __[a]__, and the coordination number of F– ions is __[b]__.

(c)

R-16 • Reserve Questions and Problems (d)

(e)

Reserve Problem 37 Compute the PPF of {110} planes for the diamond cubic crystal structure. (a) 0.29 (b) 0.34 (c) 0.42 (d) 0.56 (e) 0.68 (f) 0.71 (g) 0.74 (h) 0.82

Reserve Problem 38 Compute the planar density of atoms, in atoms per square centimeter, on a {110} plane of a defect-free diamond cubic crystal, whose atoms have a radius of [R] nanometers.

Reserve Problem 39 (f)

Compute the PPF of {100} planes for the diamond cubic crystal structure. (a) 0.29 (b) 0.34 (c) 0.42 (d) 0.56 (e) 0.68 (f) 0.71 (g) 0.74 (h) 0.82

(g)

Reserve Problem 40 Compute the planar density of atoms, in atoms per square centimeter, on a {100} plane of a defect-free diamond cubic crystal, whose atoms have a radius of [R] nanometers.

Reserve Question 41: Lattice parameters I Which crystal system(s) listed below has (have) the following relationship for the unit cell edge lengths? (h)

a=b=c (a) Cubic (b) Hexagonal (c) Tetragonal (d) Rhombohedral (e) Orthorhombic (f) Monoclinic (g) Triclinic

Reserve Questions and Problems • R-17 Reserve Question 42: Lattice parameters II

Reserve Question 46: Unit cell geometries III

Which crystal system(s) listed below has (have) the following relationship for the unit cell edge lengths?

Which crystal system(s) listed below has (have) the following interaxial angle relationship?

a=b≠c (a) Cubic (b) Hexagonal (c) Tetragonal (d) Rhombohedral (e) Orthorhombic (f) Monoclinic (g) Triclinic

α = β = 90°, γ = 120° (a) Cubic (b) Hexagonal (c) Tetragonal (d) Rhombohedral (e) Orthorhombic (f) Monoclinic (g) Triclinic

Reserve Question 43: Lattice parameters III Which crystal system(s) listed below has (have) the following relationship for the unit cell edge lengths? a≠b≠c (a) Cubic (b) Hexagonal (c) Tetragonal (d) Rhombohedral (e) Orthorhombic (f) Monoclinic (g) Triclinic

Reserve Question 47: Unit cell geometries IV Which crystal system(s) listed below has (have) the following interaxial angle relationship? α = β = γ ≠ 90° (a) Cubic (b) Hexagonal (c) Tetragonal (d) Rhombohedral (e) Orthorhombic (f) Monoclinic (g) Triclinic

Reserve Question 44: Unit cell geometries I Which crystal system(s) listed below has (have) the following interaxial angle relationship? α ≠ β ≠ γ ≠ 90° (a) Cubic (b) Hexagonal (c) Tetragonal (d) Rhombohedral (e) Orthorhombic (f) Monoclinic (g) Triclinic

Reserve Question 45: Unit cell geometries II Which crystal system(s) listed below has (have) the following interaxial angle relationship? α = β = γ = 90° (a) Cubic (b) Hexagonal (c) Tetragonal (d) Rhombohedral (e) Orthorhombic (f) Monoclinic (g) Triclinic

Reserve Question 48: Unit cell geometries V Which crystal system(s) listed below has (have) the following interaxial angle relationship? α = γ = 90° ≠ β (a) Cubic (b) Hexagonal (c) Tetragonal (d) Rhombohedral (e) Orthorhombic (f) Monoclinic (g) Triclinic

Reserve Problem 49 Sketch a tetragonal unit cell, and within that cell indi1 1 1 1 3 cate locations of the 2 1 2 and 4 2 4 point indices.

Reserve Problem 50 Sketch an orthorhombic unit cell, and within that cell 1 1 1 1 indicate locations of the 1 2 0 and 4 3 4 point indices.

R-18 • Reserve Questions and Problems Reserve Problem 51: Crystal lengths II

Reserve Question 55: Cubic direction indices 03

In terms of the atomic radius, R, determine the distance between the centers of adjacent atoms for the BCC crystal structure along the [111] direction.

What are the indices for the direction represented by the vector that has been drawn within a unit cell?

A negative index is indicated with a minus sign (“–”) in front of (rather than over) the index number.

2*R

Reserve Problem 52: SC indices

z

For the simple cubic crystal structure, in terms of the atomic radius, R, determine the distance between the centers of adjacent atoms along the [120] direction.

2 * R * √5

c

Reserve Question 53: Cubic direction indices 01 What are the indices for the direction represented by the vector that has been drawn within a unit cell?

A negative index is indicated with a minus sign (“–”) in front of (rather than over) the index number.

y

a b x

z

(a) [111]

c

(b) [1–11] y

a

(c) [11–1] (d) [–111]

b

Reserve Question 56: Cubic direction indices 04

x

What are the indices for the direction represented by the vector that has been drawn within a unit cell?

A negative index is indicated with a minus sign (“–”) in front of (rather than over) the index number.

(a) [–102] (b) [120] (c) [121] (d) 102

z

Reserve Question 54: Cubic direction indices 02 What are the indices for the direction represented by the vector that has been drawn within a unit cell?

A negative index is indicated with a minus sign (“–”) in front of (rather than over) the index number.

c

z a b x c

(a) [0–11] a b x

(a) [–002] (b) [120]

(c) [101] (d) [012]

y

(b) [1–11] (c) [01–1] (d) [–111]

y

Reserve Questions and Problems • R-19 Reserve Question 57: Cubic direction indices 05 What are the indices for the direction represented by the vector that has been drawn within a unit cell?

A negative index is indicated with a minus sign (“–”) in front of (rather than over) the index number.

A negative index is indicated with a minus sign (“–”) in front of (rather than over) the index number. z

z

c y

a c

b x

1 2

a

y

b x

(a) [–0–2–1]

(c) [–0–1–1]

(b) [–1–1–1]

(d) [–0–0–2]

Reserve Question 60: Cubic direction indices 08 What are the indices for the direction represented by the vector that has been drawn within a unit cell?

A negative index is indicated with a minus sign (“–”) in front of (rather than over) the index number.

(a) [210] (b) [200] (c) [–210] (d) [2–11]

z

Reserve Question 58: Cubic direction indices 06

1, 1 2 2

What are the indices for the direction represented by the vector that has been drawn within a unit cell?

A negative index is indicated with a minus sign (“–”) in front of (rather than over) the index number.

c y

a

z b x

Reserve Question 61: Cubic direction indices 09

c y a

What are the indices for the direction represented by the vector that has been drawn within a unit cell?

A negative index is indicated with a minus sign (“–”) in front of (rather than over) the index number. z

b x

1 3

(a) [0–21] (b) [001] (c) [201] (d) [021]

1 2

a

Reserve Question 59: Cubic direction indices 07 What are the indices for the direction represented by the vector that has been drawn within a unit cell?

c

b x

(a) [–321]

(c) [–431]

(b) [–420]

(d) [–430]

y

R-20 • Reserve Questions and Problems Reserve Question 62: Cubic direction indices 10

Reserve Problem 64

What are the indices for the direction represented by the vector that has been drawn within a unit cell?

A negative index is indicated with a minus sign (“–”) in front of (rather than over) the index number.

Select the orthorhombic unit cell illustrating a [12– 1] direction. Note: all angles are 90°. z

(a)

z

c O c

1, 1 2 2

2 3

A

a

B

b

x

y

a

y

b

C

x z

(b)

(a) [1–5–3]

O

(b) [1–4–2]

B

A

(c) [1–6–3]

c

(d) [1–6–4] y

Reserve Question 63: Cubic direction indices 11 What are the indices for the direction represented by the vector that has been drawn within a unit cell?

A negative index is indicated with a minus sign (“–”) in front of (rather than over) the index number.

C

a

b

x

z

(c)

z c O c

1, 1 2 2

2, 2 3 3

a

a

b

B

x

y

C

b x

y

A

z

(d)

(a) [–1– 43]

C

(b) [1–42]

c

(c) [0–43] O

(d) [0–41]

B

A b x

y a

Reserve Questions and Problems • R-21 Reserve Problem 65

Reserve Problem 67

Select a monoclinic unit cell illustrating a [0–11] direction. z (a)

Determine the indices for the directions shown in the following cubic unit cell:

P

+z c O

 y

2 3





1 2

1 3

A

b

1 3

C

a 2 3

x

B

D

z

(b)

2 3

O c

y





+y 1, 1 2 2

1 3

+x

P



Reserve Problem 68

b

(a) What are the direction indices for a vector 1 1 1 that passes from point 10 3 to point 2 1 2 in a tetragonal unit cell? (b) Repeat part (a) for a rhombohedral unit cell.

a x z

(c)

Reserve Problem 69 P

For tetragonal crystals, cite the indices of directions that are equivalent to each of the following directions: (a) [001] (b) [110] (c) [010]

c 

O





y

a

b

x

Reserve Problem 70

Reserve Problem 66 What are the indices for the directions indicated by the two vectors in the sketch below? +z

Direction 1 0.4 nm

+y 0.3 nm

+x

0.5 nm

Direction 2

Convert the [100] and [111] directions into the fourindex Miller–Bravais scheme for hexagonal unit cells.

R-22 • Reserve Questions and Problems Reserve Problem 71

Reserve Problem 72

Determine indices for the directions shown in the following hexagonal unit cells.

1. Select the orthorhombic unit cell with a (210) plane identified:

z

(a)

z

(a)

a2

c

a3 a1 z

(b)

y a b x a2

z

(b)

a3 a1 c

z

(c)

y

a a2

x

b

a3 a1

z

(c)

z

(d)

c

a2

y

a3 a1

a b x

Reserve Questions and Problems • R-23 2. Select the monoclinic unit cell with a (002) plane identified. z

(a)

Reserve Problem 75 Determine the Miller indices for the planes shown in the following unit cell: +z

c



 

a

b

1 2

x

B A

z

(b)

+y 2 3

c +x 





Reserve Problem 76

a

b

Find the indices of the direction that results from the intersection of each of the following pairs of planes within a cubic crystal: (a) The (100) and (010) planes (b) The (111) and (11–1) planes (c) The (10–1) and (001) planes

x z

(c)

c



Reserve Problem 77

 

Consider the reduced-sphere unit cell shown in the figure, having an origin of the coordinate system positioned at the atom labeled O. For the following sets of planes, determine which are equivalent:

a

b x

+z

Reserve Problem 73 What are the indices for the two planes drawn in the sketch below?

90°

+z Plane 2

Plane 1 0.40 nm O 90°

90° 0.30 nm

0.2 nm

+y

+x

+x 0.4 nm 0.4 nm

0.30 nm

(a) (00–1), (010), and (–100) (b) (1–10), (10–1) and (–1–10) (c) (–1–1–1), (–11–1), (–111) and (1–11)

+y

R-24 • Reserve Questions and Problems Reserve Problem 81

The accompanying figure shows three different crystallographic planes for a unit cell of a hypothetical metal. The circles represent atoms:

Identify the (a) (1−101) and (b) (11−20) planes in hexagonal unit cell. z

(a) 1.

0.46 nm

0.50 nm

0.40 nm

Reserve Problem 78

a2

0.30 nm 0.40 nm

0.35 nm (001)

a1

(101)

(110)

a3

(a) To what crystal system does the unit cell belong? (b) What would this crystal structure be called? (c) If the density of this metal is 8.95 g/cm3, determine the atomic weight.

z

2.

Reserve Problem 79 Convert the (a) (010) and (b) (101) planes into the four-index Miller–Bravais scheme for hexagonal unit cells.

a2 a3

Reserve Problem 80

a1

Determine the indices for the planes shown in the following hexagonal unit cells:

z

3. z

(a)

z

(c)

a2

a2

a1

a1 z

(b)

a2

a3

a3

a1

z

(d)

a3 z

4. a2

a2

a3

a3 a1

a1

a2 a3 a1

Reserve Questions and Problems • R-25 z

(b) 1.

Reserve Question 82: Cubic plane indices 01 What are the Miller indices for the plane shown below?

A negative index is indicated with a minus sign (“–”) in front of (rather than over) the index number. z a2

a3

c a1 z

2.

y

a b x

(a) (–100) (b) (–110) (c) (011) (d) (010)

a2

a1

Reserve Question 83: Cubic plane indices 02 What are the Miller indices for the plane shown below?

a3

A negative index is indicated with a minus sign (“–”) in front of (rather than over) the index number.

z

3.

z

c a2 a3

a a1

4.

z

(a) (110) (b) (–110) (c) (010) (d) (111)

a2

a1 a3

b x

y

R-26 • Reserve Questions and Problems Reserve Question 84: Cubic plane indices 03

Reserve Question 87: Cubic plane indices 06

What are the Miller indices for the plane shown below?

What are the Miller indices for the plane shown below?

A negative index is indicated with a minus sign (“–”) in front of (rather than over) the index number.

A negative index is indicated with a minus sign (“–”) in front of (rather than over) the index number.

z

z

c

c 1 2

a b

(a) (110) (b) (–110)

b

x

x

(a) (022) (b) (013)

(c) (010) (d) (111)

y

a

y

(c) (012) (d) (103)

Reserve Question 88: Cubic Plane indices 07

Reserve Question 85: Cubic plane indices 04

What are the Miller indices for the plane shown below?

What are the Miller indices for the plane shown below?

A negative index is indicated with a minus sign (“–”) in front of (rather than over) the index number.

A negative index is indicated with a minus sign (“–”) in front of (rather than over) the index number.

z

z

b

(a) (1–20) (b) (1–10)

b

x

(a) (40–3) (b) (41–3)

(c) (0–02) (d) (0–10)

Reserve Question 86: Cubic plane indices 05 What are the Miller indices for the plane shown below?

A negative index is indicated with a minus sign (“–”) in front of (rather than over) the index number.

(c) (41–2) (d) (40–2)

Reserve Question 89: Cubic plane indices 08 What are the Miller indices for the plane shown below?

A negative index is indicated with a minus sign (“–”) in front of (rather than over) the index number.

z

z

1 3

c

c

a x

(a) (102) (b) (1–13)

y

1 2 a

y

a x

c

2 3

c

b

(c) (112) (d) (103)

1 2

y

1 3

a x

(a) (1–13) (b) (–1–13)

b

(c) (–1–23) (d) (1–23)

y

Reserve Questions and Problems • R-27 Reserve Question 90: Cubic plane indices 09

Reserve Question 93: Hexagonal plane indices

What are the Miller indices for the plane shown below?

What are the Miller-Bravais indices for the plane shown below?

A negative index is indicated with a minus sign (“–”) in front of (rather than over) the index number. z

A negative index is indicated with a minus sign (“–”) in front of (rather than over) the index number. z

2 3

c a2

y

a b

x

(a) (2–23) (b) (1–23)

a3 a1

(c) (0–12) (d) (2–32)

Reserve Question 91: Cubic plane indices 10 What are the Miller indices for the plane shown below?

A negative index is indicated with a minus sign (“–”) in front of (rather than over) the index number. z

(a) (000–1) (b) (0010) (c) (0101) (d) (0100)

Reserve Question 94: Miller indices I Below is shown the atomic packing of a plane for the simple cubic crystal structure; atoms drawn to full size are represented by the circles.

c 2 3

1 2

x

y

a

b 2 3

(a) (42–2) (b) (31–3)

(c) (43–3) (d) (24–3)

Reserve Question 92: Cubic plane indices 11 What are the Miller indices for the plane shown below?

A negative index is indicated with a minus sign (“–”) in front of (rather than over) the index number. z

1 2

x

(a) (13–3) (b) (24–3)

Reserve Problem 95

c

2 3

a

b

(c) (14–1) (d) (15–4)

From the list below select all possible sets of indices for this plane. (a) (011) (b) (1–10) (c) (10–1) (d) (–110) (e) (0–11) (f) (110)

y

(a) Derive linear density expressions for FCC [100] and [111] directions in terms of the atomic radius R. (b) Compute and compare linear density values for these same two directions for silver.

R-28 • Reserve Questions and Problems Reserve Problem 96 Figure 3.39 shows the first four peaks of the x-ray diffraction pattern for copper, which has an FCC crystal structure; monochromatic x-radiation having a wavelength of 0.1542 nm was used. (a) Index (i.e., give h, k, and l indices) for each of these peaks. (b) Determine the interplanar spacing for each of the peaks. (c) For each peak, determine the atomic radius for Cu and compare these with the value presented in Table 3.1.

Reserve Problem 97 Below are listed diffraction angles for the first three peaks (first-order) of the x-ray diffraction pattern for some metal. Monochromatic x-radiation having a wavelength of 0.1254 nm was used. (a) Determine whether this metal’s crystal structure is FCC, BCC, or neither FCC or BCC. (b) If the crystal structure is either BCC or FCC, identify which of the metals in Table 3.1 gives this diffraction pattern.

Peak Number

Diffraction Angle (2θ)

1

31.2°

2

44.6°

3

55.4°

Reserve Question 98: Noncrystalline: anisotropic The properties of noncrystalline materials are anisotropic. (a) True (b) False

CHAPTER 4 POLYMER STRUCTURES Reserve Question 01: Double/triple bonds

Reserve Question 02: Hydrocarbon bonding

Hydrocarbon molecules that contain double and/or triple bonds are called (a) unsaturated. (b) saturated.

Which type(s) of bonding is (are) found within hydrocarbon molecules? (a) Ionic bonding (b) Hydrogen boning (c) Covalent bonding (d) Van der Waals bonding (e) Metallic bonding

Reserve Questions and Problems • R-29 Reserve Question 03: Hydrocarbon groups

Reserve Question 06: Repeat unit structures

Select the correct name of each hydrocarbon group that is shown below.

A. R

From the pull-down menus, select the correct name for each repeat unit structure that is shown below.

C

A.

O

H

B.

R

O

C.

R

OH

D.

F

F

C

C

F

F

H

CH3

C

C

H

C

R′

B.

R O

O CH3

E.

OH R

C.

C O

Group A ______ Group B ______ Group C ______ Group D ______ Group E ______

D.

H

H

C

C

H

Cl

H

H

C

C

H

Reserve Question 04: Isomers Hydrocarbon compounds that have the same composition but different atomic arrangements are called ____.

E.

Reserve Question 05: Crystallinity comparisons For the following two polymers: Linear polyethylene Lightly branched isotactic polypropylene Is it possible to determine if one is more likely to crystallize than the other? (a) Yes. Linear polyethylene (b) Yes. Lightly branched isotactic polypropylene (c) No

F.

H

H

C

C

H

H

H

H

C

C

H

CH3

Repeat unit A ______ Repeat unit B ______ Repeat unit C ______ Repeat unit D ______ Repeat unit E ______ Repeat unit F ______

R-30 • Reserve Questions and Problems Reserve Problem 07: Substitution of group

Reserve Question 11: Cis/trans identification

Polyethylene may be fluorinated by inducing the random substitution of fluorine atoms for hydrogen.

Indicate which structure has the cis configuration and which has the trans configuration.

For this polymer, determine the following: (a) The concentration of F (in wt%) that must be added if this substitution occurs for 18.6% of all of the original hydrogen atoms. (b) The concentration of F (in wt%) that must be added to completely fluorinate the material, i.e. to produce polytetrafluoroethylene (PTFE).

Atomic weights for several elements are included in the following table: Carbon 12.01 g/mol Chlorine 35.45 g/mol Fluorine 19.00 g/mol Hydrogen 1.008 g/mol Oxygen 16.00 g/mol

Reserve Question 08: Linear polymers Which of the following may form linear polymers? (a) Rubber (b) Epoxy (c) Polyethylene (d) Phenol-formaldehyde (e) Polystyrene (f) Nylon

Reserve Question 09: Network polymers Which of the following form network polymers? (a) Rubber (b) Epoxy

H

H

C

C

H

H C

C

H

H

H

H

H

H

C

C

C

C

H

H

______

______

Reserve Question 12: Isotactic/syndiotactic/atactic Match the description of each stereoisomer with the name of its configuration classification.

All R groups are on the same side. ______ R groups are alternate sides of the chain. ______ R groups are randomly positioned along the chain. ______

Reserve Question 13: Polymer configuration For most polymers, which configuration predominates? (a) Head-to-head (b) Head-to-tail

Reserve Problem 14 Five pieces of plastic, each one made of a different polymer, feature the same degree of polymerization.

Which one will feature, on average, the shortest molecules when fully extended? (a) PVC

(c) Polyethylene

(b) PE

(d) Phenol-formaldehyde

(c) PTFE

(e) Polystyrene

(d) PP

(f) Nylon

(e) PS (f) They are equal lengths.

Reserve Question 10: Cis/Trans Match the geometrical isomer descriptions with their names.

Groups bonded to adjacent doubly-bonded chain atoms are positioned on the same chain side. ______ Groups bonded to adjacent doubly-bonded chain atoms are positioned on opposite chain sides. ______

Reserve Questions and Problems • R-31 Reserve Problem 15a (question pool)

Reserve Problem 16a (question pool)

Which of the following schematics is consistent with a polymer architecture featuring PE grafted onto a PTFE-PVC block-copolymer primary chain? Each circle is considered to be a repeat unit. (d) (a)

Which of the following schematics is consistent with a polymer architecture featuring PE grafted onto a PP primary chain? Each circle is considered to be a repeat unit. (d) (a)

(b)

(c)

(e)

(b)

(c)

(e)

R-32 • Reserve Questions and Problems Reserve Problem 17a (question pool)

Reserve Problem 18a (question pool)

Which of the following schematics is consistent with a polymer architecture featuring PE grafted onto a PP primary chain? Each circle is considered to be a repeat unit. (d) (a)

Which of the following schematics is consistent with a polymer architecture featuring PE grafted onto a PP-PVC alternating-copolymer primary chain? Each circle is considered to be a repeat unit. (d) (a)

(b)

(c)

(e)

(b)

(c)

(e)

Reserve Questions and Problems • R-33 Reserve Problem 19a (question pool)

Reserve Problem 20a (question pool)

Which of the following schematics is consistent with a polymer architecture featuring PP grafted onto a PP-PVC alternating-copolymer primary chain? Each circle is considered to be a repeat unit. (d) (a)

Which of the following schematics is consistent with a polymer architecture featuring PP-PVC grafted onto a PP primary chain? Each circle is considered to be a repeat unit.

(b)

(a)

(d)

(b)

(e)

(e)

(c) (c)

Reserve Question 21: Polymer crystallinity Is it possible to produce a polymer that is 100% crystalline? (a) True (b) False

R-34 • Reserve Questions and Problems

CHAPTER 5 IMPERFECTIONS IN SOLIDS Reserve Problem 01a (question pool) Consider the schematic nanostructure depicted below.

Reserve Problem 02a (question pool)

Which of the following statements is FALSE regarding this schematic structure?

Which of the following statements is FALSE regarding this schematic structure?

Do not extrapolate the field of view. Consider only what you are shown.

Do not extrapolate the field of view. Consider only what you are shown.

(a) Each of the phases features a similar concentration of vacancies. (b) The microstructure features exactly two components and two different phases. (c) None of the phases present features interstitial impurities. (d) Only one phase boundary is depicted. (e) Two grain boundaries are depicted.

Consider the schematic nanostructure depicted below.

(a) Each of the phases features a similar concentration of vacancies. (b) The microstructure features exactly two components and two different phases. (c) One of the phases present features interstitial impurities. (d) Only one phase boundary is depicted. (e) One grain boundary is depicted.

Reserve Questions and Problems • R-35 Reserve Problem 03a (question pool) Consider the schematic nanostructure depicted below.

Which of the following statements is FALSE regarding this schematic structure?

Do not extrapolate the field of view. Consider only what you are shown.

Reserve Problem 05: Metallic vacancies– temperature The number of vacancies present in some metal at 864°C is 1.1 × 1024 m−3. Calculate the number of vacancies at 463°C given that the energy for vacancy formation is 1.25 eV/atom; assume that the density at both temperatures is the same.

Reserve Question 06: Vacancies vs. self-interstitials In metals, there are significantly more vacancies than self-interstitials. (a) True (b) False

Reserve Problem 07 Using the following data that relate to the formation of Schottky defects in some oxide ceramic (having the chemical formula MO), determine the following: T ( °C)

(g/cm3)

Ns (m−3)

750

5.50

9.21 × 1019

1000

5.44

?

1250

5.37

5.0 × 1022

(a) The energy for defect formation (in eV). (b) The equilibrium number of Schottky defects per cubic meter at 1000°C. (c) The identity of the oxide (i.e., what is the metal M?).

Reserve Problem 08

(a) Each of the phases features a similar concentration of vacancies. (b) The microstructure features exactly three components and two different phases. (c) Both of the phases present features interstitial impurities. (d) Only one phase boundary is depicted. (e) One grain boundary is depicted.

Reserve Problem 04: Energy from temperature The number of vacancies in some hypothetical metal increases by a factor of 5 when the temperature is increased from 1040 K to 1150 K. Calculate the energy (in kJ/mol) for vacancy formation assuming that the density of the metal remains the same over this temperature range.

Which of the following oxides would you expect to form substitutional solid solutions that have complete (i.e., 100%) solubility with MnO? Explain your answers. (a) MgO (b) CaO (c) BeO (d) NiO

Reserve Problem 09 (a) Suppose that Li2O is added as an impurity to CaO. If the Li+ substitutes for Ca2+, what kind of vacancies would you expect to form?

How many of these vacancies are created for every Li+ added? (b) Suppose that CaCl2 is added as an impurity to CaO. If the Cl− substitutes for O2−, what kind of vacancies would you expect to form? How many of the vacancies are created for every Cl− added?

R-36 • Reserve Questions and Problems Reserve Problem 10

Reserve Problem 11: Wt% to concentration

Atomic radius, crystal structure, electronegativity, and the most common valence are given in the following table for several elements; for those that are nonmetals, only atomic radii are indicated.

The concentration of carbon in an iron-carbon alloy is 0.57 wt%. What is the concentration in kilograms of carbon per cubic meter of alloy? The densities of iron and carbon are 7.87 and 2.25 g/cm3, respectively.

Element

Atomic Radius (nm)

Crystal Structure

Electronegativity

Valence

Cu

0.1278

FCC

1.9

+2

C H O

0.071 0.046 0.060

Ag

0.1445

FCC

1.9

+1

Al

0.1431

FCC

1.5

+3

Co

0.1253

HCP

1.8

+2

Cr

0.1249

BCC

1.6

+3

Fe

0.1241

BCC

1.8

+2

Ni

0.1246

FCC

1.8

+2

Pd

0.1376

FCC

2.2

+2

Pt

0.1387

FCC

2.2

+2

Zn

0.1332

HCP

1.6

+2

Reserve Problem 12 The concentration of gallium in silicon is 5.0 × 10−7 at%. What is the concentration in kilograms of gallium per cubic meter?

Reserve Problem 13

Choose which of these elements you would expect to form the following with copper: A substitutional solid solution having complete solubility • Ni • C • O • Zn • H • Ag • Pt • Al • Pd • Cr • Co • Fe A substitutional solid solution of incomplete solubility • Pd • Ni • Al • Zn • Cr • C • Fe • Ag • H • O • Pt • Co An interstitial solid solution • C • Zn • Pd • Ag • Pt • Al • H • Co • Cr • Fe • O • Ni

Some hypothetical alloy is composed of 12.5 wt% of metal A and 87.5 wt% of metal B. If the densities of metals A and B are 4.27 and 6.35 g/cm3, respectively, whereas their respective atomic weights are 61.4 and 125.7 g/mol, determine whether the crystal structure for this alloy is simple cubic, face-centered cubic, or body-centered cubic. Assume a unit cell edge length of 0.395 nm.

Reserve Problem 14 For a BCC iron-carbon alloy that contains 0.15 wt% C, calculate the fraction of unit cells that contain carbon atoms.

Reserve Problem 15 For Si to which has had added 1.5 × 10−6 at% of arsenic, calculate the number of As atoms per cubic meter.

Reserve Problem 16 Electronic devices found in integrated circuits are composed of very high purity silicon to which has been added small and very controlled concentrations of elements found in Groups IIIA and VA of the periodic table. For Si that has had added 8.3 × 1021 atoms per cubic meter of antimony, compute (a) the weight percent and (b) the atom percent of Sb present.

Reserve Problem 17 Iron and vanadium both have the BCC crystal structure and V forms a substitutional solid solution in Fe for concentrations up to approximately 20 wt% V at room temperature. Determine the concentration in weight percent of V that must be added to iron to yield a unit cell edge length of 0.289 nm.

Reserve Problem 18: Linear defects Which of the following is a (are) linear defect(s)? (a) An edge dislocation (b) A Frenkel defect (c) A Schottky defect

Reserve Questions and Problems • R-37 Reserve Problem 19: ASTM grain size I

Reserve Problem 20

A photomicrograph was taken of a specimen at a magnification of 100×, and it was determined that the average number of grains per square inch was 200.

What is this specimen’s ASTM grain size number?

For a single crystal of some hypothetical metal that has the simple cubic crystal structure (Figure 3.3), would you expect the surface energy for a (100) plane to be greater, equal to, or less than a (110) plane?

CHAPTER 6 DIFFUSION Reserve Question 01: Rate of Diffusion

Reserve Problem 04

Diffusion by which mechanism occurs more rapidly in metal alloys? (a) Vacancy diffusion (b) Interstitial diffusion

If [m] atoms of helium pass through a [a] square meter plate area every [t] hours, and if this flux is constant with time, compute the flux of helium in units of atoms per square meter per second.

Reserve Question 02: Temperature effect in diffusion As temperature decreases, the fraction of total number of atoms that are capable of diffusive motion (a) increases. (b) decreases.

Reserve Problem 03 A gas mixture is found to contain two diatomic A and B species for which the partial pressures of both are 0.05065 MPa (0.5 atm). This mixture is to be enriched in the partial pressure of the A species by passing both gases through a thin sheet of some metal at an elevated temperature. The resulting enriched mixture is to have a partial pressure of 0.02026 MPa (0.2 atm) for gas A, and 0.01013 MPa (0.1 atm) for gas B. The concentrations of A and B (CA and CB, in mol/m3) are functions of gas partial pressures (pA2 and pB2, in MPa) and absolute temperature according to the following expressions: CA = 200 √pA2 exp(−

25.0 kJ mol )

RT

CB = 1.0 × 10−3 √pB2 exp(−

30.0 kJ mol RT

)

Furthermore, the diffusion coefficients for the diffusion of these gases in the metal are functions of the absolute temperature as follows: DA (m2 s) = 4.0 × 10−7 exp − ( DB (m2 s) = 2.5 × 10−6 exp(−

15.0 kJ mol RT

)

24.0 kJ mol RT

)

Is it possible to purify the A gas in this manner? If so, specify a temperature at which the process may be carried out, and also the thickness of metal sheet that would be required. If this procedure is not possible, then state the reason(s) why.

Reserve Problem 05 If water molecules pass through a membrane with a steady state flux of [j] mole/(m2 day), how long will it take, in hours, for [m] kg of water to pass through a [a] square centimeter of the membrane?

Reserve Problem 06a (question pool) The cornea is the transparent outer layer of the human eye. Because it must be transparent to light, it does not normally contain blood vessels. Therefore, it must receive its nutrients via diffusion. Oxygen from the surrounding air diffuses to the cornea through the surface tears, whereas other nutrients diffuse to the cornea from the inner parts of the eye, such as the vitreous humor and lens.

During operation, the cornea produces waste in the form of CO2 gas that must be expelled to keep the eye healthy and functioning. This is accomplished by the simultaneous diffusion of CO2 from the cornea to the surrounding atmosphere, which generally features a low CO2 concentration.

It is therefore critical that modern contact lens materials allow sufficient diffusion rates of oxygen and carbon dioxide. Without oxygen, the cornea will warp, lose transparency, and become susceptible to scarring. The body may also react by growing additional blood vessels into the eye, which can damage the cornea.

If an increased steady-state flow rate of O2 (oxygen molecules per second) to the cornea is desired, which of the following contact lens/ambient condition modifications is not likely to be useful?

Note: the flow rate is equal to product of the diffusion flux and an area of interest through which diffusion occurs. (a) Increase the contact lens thickness (b) Increase the diffusivity of oxygen gas by decreasing the contact lens porosity (c) Increase the ambient temperature (d) Increase the ambient partial pressure of oxygen gas (e) All of the suggestions (a-d) are useful for increasing the flow rate of oxygen

R-38 • Reserve Questions and Problems Reserve Problem 07: Non-steady-state–Specific concentration at different T For a steel alloy it has been determined that a carburizing heat treatment of 16 h duration at 757°C will raise the carbon concentration to 0.5 wt% at a point 2.3 mm from the surface. Estimate the time necessary to achieve the same concentration at a 8 mm position for an identical steel and at a carburizing temperature of 1130°C. Assume that D0 is 4.6 × 10−5 m2/s and Qd is 104 kJ/mol.

Reserve Problem 08a (question pool) The figure below features diffusion profiles that developed within four separate plain-carbon steel specimens of equivalent geometry after they separately experienced a carburization process. The specimens were prepared such that the scenario of a one-dimensional semi-infinite solid applies as a solution to Fick’s 2nd Law of Diffusion. Each part originally contained a uniform distribution of carbon, and each part was processed using the same carburization temperature.

In the figure, x = 0 corresponds to the surfaces of the steel parts that were exposed to the carbon-rich atmosphere during the diffusion process.

Answer True or False for each of the following statements. (a) The carburization surface was maintained at 1.00 wt% carbon for each specimen. (b) Comparing the finished specimens at a depth of 0.75 mm, specimen A features the largest carbon concentration. (c) Comparing the finished specimens as a whole, specimen A features the lowest overall amount of carbon. (d) Specimen B experienced a longer carburization time compared to specimen C. (e) The initial concentration of carbon in each part (prior to carburization) was a little less than 0.25 wt% carbon.

Reserve Problem 09 The diffusion coefficient for aluminum in silicon is DAl in Si = 3 × 10−16 cm2/s at 300 K (note that 300 K is about room temperature).

What is a reasonable value for DAl in Si at 600 K ?

Note: Rather than performing a specific calculation, you should be able to justify your answer from the options below based on the mathematical temperature dependence of the diffusion coefficient. (a) D < 3 × 10−16 cm2/s (b) D = 3 × 10−16 cm2/s (c) D = 6 × 10−16 cm2/s (d) D = 1.5 × 10−16 cm2/s (e) D > 6 × 10−16 cm2/s (f) D = 6 × 10−17 cm2/s

Reserve Problem 10a (question pool) Depicted below are five different steady-state concentration profiles for the same gas across five separate and identical plastic membranes at the same temperature. Which concentration profile results in the lowest diffusion flux through the membrane?

Reserve Problem 11 One integrated circuit design calls for the diffusion of arsenic into silicon wafers; the background concentration of As in Si is 2.5 × 1020 atoms/m3. The predeposition heat treatment is to be conducted at 1000°C for 45 minutes, with a constant surface concentration of 8 × 1026 As atoms/m3. At a drive-in treatment temperature of 1100°C, determine the diffusion time required for a junction depth of 1.2 μm. For this system, values of Qd and D0 are 4.10 eV and 2.29 × 10−3 m2/s, respectively.

Reserve Questions and Problems • R-39 Reserve Problem 12

Reserve Problem 13

Phosphorus atoms are to be diffused into a silicon wafer using both predeposition and drive-in heat treatments; the background concentration of P in this silicon material is known to be 5 × 1019 atoms/m3.

The predeposition treatment is to be conducted at 950°C for 45 minutes; the surface concentration of P is to be maintained at a constant level of 1.5 × 1026 atoms/m3. Drive-in diffusion will be carried out at 1200°C for a period of 2.5 h. For the diffusion of P in Si, values of Qd and D0 are 3.40 eV and 1.1 × 10−4 m2/s, respectively. (a) Calculate the value of Q0. (b) Determine the value of xj for the drive-in diffusion treatment. (c) Also for the drive-in treatment, compute the position x at which the concentration of P atoms is 1024 m−3.

Aluminum atoms are to be diffused into a silicon wafer using both predeposition and drive-in heat treatments; the background concentration of Al in this silicon material is known to be 3 × 1019 atoms/m3.

The drive-in diffusion treatment is to be carried out at 1050°C for a period of 4.0 h, which gives a junction depth xj of 3.0 μm. Compute the predeposition diffusion time at 950°C if the surface concentration is maintained at a constant level of 2 × 1025 atoms/m3.

For the diffusion of Al in Si, values of Qd and D0 are 3.41 eV and 1.38 × 10−4 m2/s, respectively.

CHAPTER 7 MECHANICAL PROPERTIES Reserve Problem 01a-1 (question pool)

Reserve Problem 01c-1 (question pool)

Each of the rods depicted below were machined from same stock metal. If the same force is applied axially to each rod, which one will experience the highest stress?

Each of the rods depicted below were machined from same stock metal. If the same force is applied axially to each rod, which one will experience the highest stress?

Reserve Problem 01d-1 (question pool) Reserve Problem 01b-1 (question pool) Each of the rods depicted below were machined from same stock metal. If the same force is applied axially to each rod, which one will experience the highest stress?

Each of the rods depicted below were machined from same stock metal. If the same force is applied axially to each rod, which one will experience the highest stress?

R-40 • Reserve Questions and Problems Reserve Problem 01e-1 (question pool)

(c)

(e)

(d)

(f)

Each of the rods depicted below were machined from same stock metal. If the same force is applied axially to each rod, which one will experience the highest stress?

Reserve Problem 01f-1 (question pool) Each of the rods depicted below were machined from same stock metal. If the same force is applied axially to each rod, which one will experience the highest stress?

Reserve Problem 03: Stress-strain I A specimen of some metal having a rectangular cross section 11.2 mm × 12.4 mm is pulled in tension with a force of 31200 N, which produces only elastic deformation. Given that the elastic modulus of this metal is 63 GPa, calculate the resulting strain.

Reserve Problem 02a (question pool) Each of the rods depicted below were machined from same stock metal. They were originally machined to be the same length, but their cross-sectional areas were different. Which plot correctly depicts the force required to elastically elongate these specimens?

Reserve Problem 04: Maintaining plastic deformation For a bronze alloy, the stress at which plastic deformation begins is 277 MPa and the modulus of elasticity is 117 GPa. (a) What is the maximum load that may be applied to a specimen having a cross-sectional area of 327 mm2 without plastic deformation? (b) If the original specimen length is 148 mm, what is the maximum length to which it may be stretched without causing plastic deformation?

Reserve Problem 05

(a)

(b)

A steel bar 100 mm (4.0 in.) long and having a square cross section 20 mm (0.8 in.) on an edge is pulled in tension with a load of 89,000 N (20,000 lbf), and experiences an elongation of 0.10 mm (4.0 × 10−3 in.).

Assuming that the deformation is entirely elastic, calculate the elastic modulus of the steel.

Reserve Problem 06 Figure 7.35 shows, for a gray cast iron, the tensile engineering stress–strain curve in the elastic region. Determine (a) the tangent modulus at 10.3 MPa (1500 psi), and (b) the secant modulus taken to 6.9 MPa (1000 psi).

Reserve Questions and Problems • R-41 Reserve Question 07 Using the expression to which the modulus of elasticity is proportional, dF =− ( dr )r 0

2A 3 (1−n)

A ( nB )

+

n(n + 1)B A (n+2) (1−n) ( nB )

.

Reserve Problem 08c-1 (question pool) Each of the rods depicted below were machined from same stock metal. They were originally machined to be the same length, but their cross-sectional areas were different. If axial force is applied to each rod such that they all change length by the same amount, which rod experienced the largest force?

rank the magnitudes of the moduli of elasticity for the following hypothetical X, Y, and Z materials from the greatest to the least. The appropriate A, B and n parameters (Equation 7.36) for these three materials are tabulated below; they yield EN in units of electron volts and r in nanometers: Material X

A 2.5

B 2.0 × 10

n 8

Y

2.3

8.0 × 10–6

10.5

Z

3.0

1.5 × 10–5

9

–5

The highest modulus of elasticity is Metal ______ The next highest modulus of elasticity is Metal ______ The least modulus of elasticity is Metal ______

Reserve Problem 08d-1 (question pool) Each of the rods depicted below were machined from same stock metal. They were originally machined to be the same length, but their cross-sectional areas were different. If axial force is applied to each rod such that they all change length by the same amount, which rod experienced the largest force?

Reserve Problem 08a-1 (question pool) Each of the rods depicted below were machined from same stock metal. They were originally machined to be the same length, but their cross-sectional areas were different. If axial force is applied to each rod such that they all change length by the same amount, which rod experienced the largest force?

Reserve Problem 09: Poisson’s ratio II

Reserve Problem 08b-1 (question pool) Each of the rods depicted below were machined from same stock metal. They were originally machined to be the same length, but their cross-sectional areas were different. If axial force is applied to each rod such that they all change length by the same amount, which rod experienced the largest force?

A cylindrical specimen of some metal alloy 10 mm in diameter and 150 mm long has a modulus of elasticity of 100 GPa. Does it seem reasonable to expect a tensile stress of 200 MPa to produce a reduction in specimen diameter of 0.08 mm? Assume that the deformation is totally elastic. (a) Yes (b) No

Reserve Problem 12: Stress for tension test Consider the brass alloy the stress-strain behavior of which is shown in the Animated Figure 7.12. A cylindrical specimen of this alloy 21 mm in diameter and 224 mm long is to be pulled in tension. Calculate the stress (in MPa) necessary to cause a 0.00832 mm reduction in diameter. Assume a value of 0.33 for Poisson’s ratio.

R-42 • Reserve Questions and Problems Reserve Problem 13: Typical relationship between E and G

Reserve Problem 16: Load for elongation

For most metals, the relationship between elastic and shear moduli is approximately which of the following? (a) G = 0.1 E (d) G = 0.4 E (b) G = 0.2 E (e) G = 0.5 E (c) G = 0.3 E

Consider the brass alloy the stress-strain behavior of which is shown in the Animated Figure 7.12. A cylindrical specimen of this material 13.7 mm in diameter and 142.1 mm long is pulled in tension after which the tensile load is released. After the load is released the total length has still increased to 142.4 mm. Calculate the magnitude of the load (in N) necessary to cause this elongation.

Reserve Problem 14

Reserve Problem 17

A cylindrical metal specimen 12.7 mm (0.5 in.) in diameter and 250 mm (10 in.) long is to be subjected to a tensile stress of 28 MPa (4000 psi); at this stress level, the resulting deformation will be totally elastic. (a) If the elongation must be less than 0.080 mm (3.2 × 10−3 in.), which of the metals in Table 6.1 are suitable candidates?

• Brass • Copper • Tungsten • Steel • Titanium • Nickel • Magnesium • Aluminum (b) If, in addition, the maximum permissible diameter decrease is 1.2 × 10−3 mm (4.7 × 10−5 in.) when the tensile stress of 28 MPa is applied, which of the metals that satisfy the criterion in part (a) are suitable candidates?

• Aluminum • Brass • Steel • Magnesium • Copper • Titanium • Nickel • Tungsten

A cylindrical specimen of aluminum having a diameter of 0.505 in. (12.8 mm) and a gauge length of 2.000 in. (50.800 mm) is pulled in tension. Use the load–elongation characteristics shown in the following table to complete parts (a) through (e).

Reserve Problem 15 A cylindrical rod 380 mm (15.0 in.) long and having a diameter of 10.0 mm (0.40 in.), is to be subjected to a tensile load. If the rod is to experience neither plastic deformation nor an elongation of more than 0.9 mm (0.035 in.) when the applied load is 24,500 N (5500 lbf), which of the four metals or alloys listed below are possible candidates?

Material Aluminum alloy Brass alloy Copper Steel alloy

Modulus of Elasticity (GPa) 70 100 110 207

• Aluminum alloy • Brass alloy • Copper • Steel alloy

Yield Strength (MPa) 255 345 250 450

Tensile Strength (MPa) 420 420 290 550

Load in N

Load in lbf

Length in mm

Length in in.

0 7330 15,100 23,100 30,400 34,400 38,400 41,300 44,800 46,200 47,300 47,500 46,100 44,800 42,600 34,400 Fracture

0 1650 3400 5200 6850 7750 8650 9300 10,100 10,400 10,650 10,700 10,400 10,100 9600 8200 Fracture

50.800 50.851 50.902 50.952 51.003 51.054 51.308 51.816 52.832 53.848 54.864 55.880 56.896 57.658 58.420 59.182 Fracture

2.000 2.002 2.004 2.006 2.008 2.010 2.020 2.040 2.080 2.120 2.160 2.200 2.240 2.270 2.300 2.330 Fracture

Plot the data as engineering stress versus engineering strain. Based on your plot, (a) Compute the modulus of elasticity. (b) Determine the yield strength at a strain offset of 0.002. (c) Determine the tensile strength of this alloy. (d) What is the approximate ductility, in percent elongation? (e) Compute the modulus of resilience. (a) ______ GPa (d) ______ %EL (b) ______ MPa (e) ______ J/m3 (c) ______ MPa

Reserve Questions and Problems • R-43 Reserve Problem 18

Reserve Problem 19a-1 (question pool)

A specimen of ductile cast iron having a rectangular cross section of dimensions 4.8 mm × 15.9 mm (3/16 in. × 5/8 in.) is deformed in tension. Using the load–elongation data shown in the following table, complete problems (a) through (e).

Three hypothetical tensile engineering stress-strain curves through failure are depicted below.

Load in N

Load in lbf

Length in mm

Length in in.

0 4740 9140 12,920 16,540 18,300 20,170 22,900 25,070 26,800 28,640 30,240 31,100 31,280 30,820 29,180 27,190 24,140 18,970 Fracture

0 1065 2055 2900 3720 4110 4530 5145 5635 6025 6440 6800 7000 7030 6930 6560 6110 5430 4265 Fracture

75.000 75.025 75.050 75.075 75.113 75.150 75.225 75.375 75.525 75.750 76.500 78.000 79.500 81.000 82.500 84.000 85.500 87.000 88.725 Fracture

2.953 2.954 2.955 2.956 2.957 2.959 2.962 2.968 2.973 2.982 3.012 3.071 3.130 3.189 3.248 3.307 3.366 3.425 3.493 Fracture

Which response is considered to be the most brittle?

Reserve Problem 19b-1 (question pool) Three hypothetical tensile engineering stress-strain curves through failure are depicted below.

Which response is considered to be the most brittle?

Reserve Problem 19c-1 (question pool) Plot the data as engineering stress versus engineering strain. (a) Compute the modulus of elasticity. (b) Determine the yield strength at a strain offset of 0.002. (c) Determine the tensile strength of this alloy. (d) Compute the modulus of resilience. (e) What is the ductility, in percent elongation? (a) ______ GPa (b) ______ MPa (c) ______ MPa (d) ______ J/m3 (e) ______%EL

Three hypothetical tensile engineering stress-strain curves through failure are depicted below.

Which response is considered to be the most brittle?

R-44 • Reserve Questions and Problems Reserve Problem 19d-1 (question pool)

Reserve Problem 20a (question pool)

Three hypothetical tensile engineering stress-strain curves through failure are depicted below.

Tensile engineering stress-strain curves through failure are depicted below.

Which response is considered to be the most brittle?

Which specimen features the most ductile response?

Reserve Problem 19e-1 (question pool) Three hypothetical tensile engineering stress-strain curves through failure are depicted below.

Which response is considered to be the most brittle?

(a) 1340 Steel, Water-Quenched & Tempered at 370oC (b) Stainless Steel (18-8) (c) Aluminum Alloy 2024-T81 (d) Structural Steel (Mild Steel) (e) Magnesium

Reserve Problem 21: True strain A tensile test is performed on a specimen of some metal alloy, and it is found that a true plastic strain of 0.12 is produced when a true stress of 280 MPa is applied. For this alloy, the value of the strain hardening exponent is 0.3.

On the basis of these data, what true plastic strain would be expected for a total true plastic stress of 330 MPa?

Reserve Problem 22: True stress Reserve Problem 19f-1 (question pool) Three hypothetical tensile engineering stress-strain curves through failure are depicted below.

Which response is considered to be the most brittle?

A cylindrical specimen of a metal alloy 48.8 mm long and 9.09 mm in diameter is stressed in tension. A true stress of 327 MPa causes the specimen to plastically elongate to a length of 55 mm. If it is known that the strain-hardening exponent for this alloy is 0.3, calculate the true stress (in MPa) necessary to plastically elongate a specimen of this same material from a length of 48.8 mm to a length of 57.6 mm.

Reserve Problem 23 A three-point transverse bending test is conducted on a cylindrical specimen of aluminum oxide having a reported flexural strength of 390 MPa (56,600 psi).

If the specimen radius is 2.5 mm (0.10 in.) and the support point separation distance is 30 mm (1.2 in.), predict whether or not you would expect the specimen to fracture when a load of 620 N (140 lbf) is applied.

Calculate the value of flexural strength for this test.

Reserve Questions and Problems • R-45 Reserve Problem 24 Using the date in the table below, do the following: (a) Determine the flexural strength for nonporous MgO assuming a value of 3.75 for n in Equation 7.22. (b) Compute the volume fraction porosity at which the flexural strength for MgO is 62 MPa (9000 psi).

Material Silicon nitride (Si3N4) Zirconiaa (ZrO2) Silicon carbide (SiC) Aluminum oxide (Al2O3) Glass-ceramic (Pyroceram) Mullite (3Al2O3–2SiO2) Spinel (MgAl2O4) Magnesium oxide (MgO) Fused silica (SiO2) Soda-lime glass

Flexural Strength MPa ksi 250–1000 35–145 800–1500 115–215 100–820 15–120 275–700 40–100 247 36 185 27 110–245 16–35.5 15b 105b 110 16 69 10

Modulus of Elasticity GPa 106 psi 304 44 205 30 345 50 393 57 120 17 145 21 260 38 225 33 73 11 69 10

Reserve Problem 25 The flexural strength and associated volume fraction porosity for two specimens of the same ceramic material are as follows: σfs (MPa) 100 50

P 0.05 0.20

(a) Compute the flexural strength for a completely nonporous specimen of this material. (b) Compute the flexural strength for a 0.10 volume fraction porosity.

Reserve Problem 26a (question pool) Which polymer listed in the table below would feature the lowest tensile yield point?

Option (a) (b) (c) (d) (e)

Identity PP PP PP PP PP

Degree of Polymerization 3,000 3,000 150,000 275,000 275,000

Architecture Linear Branched Linear Branched Linear

% Crystalline 20 20 45 45 65

Reserve Problem 27a (question pool) Which polymer listed in the table below would feature the highest tensile yield point?

Option (a) (b) (c) (d) (e)

Identity PP PP PP PP PP

Degree of Polymerization 3,000 3,000 150,000 275,000 275,000

Architecture Linear Branched Linear Branched Linear

% Crystalline 20 20 45 45 65

R-46 • Reserve Questions and Problems Reserve Problem 28a (question pool) Which polymer listed in the table below would feature the lowest elastic modulus?

Option (a) (b) (c) (d) (e)

Identity PP PP PP PP PP

Degree of Polymerization 3,000 3,000 150,000 275,000 275,000

Architecture Linear Branched Linear Branched Linear

% Crystalline 20 20 45 45 65

Reserve Problem 29a (question pool) Which polymer listed in the table below would feature the highest elastic modulus?

Option (a) (b) (c) (d) (e)

Identity PP PP PP PP PP

Degree of Polymerization 3,000 3,000 150,000 275,000 275,000

Architecture Linear Branched Linear Branched Linear

% Crystalline 20 20 45 45 65

Reserve Problem 30a (question pool) Which polymer listed in the table below would feature the lowest density?

Option (a) (b) (c) (d) (e)

Identity PP PP PP PP PP

Degree of Polymerization 3,000 3,000 150,000 275,000 275,000

Architecture Linear Branched Linear Branched Linear

% Crystalline 20 20 45 45 65

Reserve Problem 31a (question pool) Which polymer listed in the table below would feature the highest density?

Option (a) (b) (c) (d) (e)

Identity PP PP PP PP PP

Degree of Polymerization 3,000 3,000 150,000 275,000 275,000

Architecture Linear Branched Linear Branched Linear

% Crystalline 20 20 45 45 65

Reserve Questions and Problems • R-47 Reserve Problem 32a (question pool) Which polymer listed in the table below would feature the lowest thermal expansion coefficient?

Option (a) (b) (c) (d) (e)

Degree of Polymerization 3,000 3,000 150,000 275,000 275,000

Identity PP PP PP PP PP

Architecture Linear Branched Linear Branched Linear

% Crystalline 20 20 45 45 65

Reserve Problem 33a (question pool) Which polymer listed in the table below would feature the highest thermal expansion coefficient?

Option (a) (b) (c) (d) (e)

Degree of Polymerization 3,000 3,000 150,000 275,000 275,000

Identity PP PP PP PP PP

Architecture Linear Branched Linear Branched Linear

% Crystalline 20 20 45 45 65

Reserve Problem 34a (question pool)

Reserve Problem 35a (question pool)

Assuming the stress-strain curves provide below all correspond to the same polymer, which tensile test was most likely performed at the highest temperature above Tg? Choose (e) if no tests likely meet this condition.

Assuming the stress-strain curves provide below all correspond to the same polymer tested at the same temperature, which tensile test was most likely performed with the highest strain rate?

80

80

a

70

70 60 b

Stress (MPa)

Stress (MPa)

60 50 40 c

30

b 50 40 c

30

20

20 d

10 0 0

a

0.1

0.2 Strain

d

10

0.3

0 0

0.1

0.2 Strain

0.3

R-48 • Reserve Questions and Problems Reserve Problem 36 (a) Consider a thin-walled cylindrical tube having a radius of 65 mm that is to be used to transport pressurized gas. If inside and outside tube pressures are 100 and 1.0 atm (10.13 and 0.1013 MPa), respectively, compute the minimum required thickness for each of the following metal alloys. Assume a factor of safety of 3.5.

Alloy Steel (plain) Steel (alloy) Cast iron Aluminum Magnesium

Yield Strength, σy (MPa) 375 1000 225 275 175

Density, ρ (g/cm3) 7.8 7.8 7.1 2.7 1.80

Unit Mass Cost, cˉ ($US/kg) 1.65 4.00 2.50 7.50 15.00

• Steel (plain) ______ • Steel (alloy) ______ • Cast iron ______ • Aluminum ______ • Magnesium ______ (b) A tube constructed of which of the alloys will cost the least amount?

• Cast iron • Aluminum • Magnesium • Steel (plain) • Steel (alloy)

CHAPTER 8 DEFORMATION AND STRENGTHENING MECHANISMS Reserve Question 01: Atomic ordering with edge dislocations

Reserve Question 06: Theoretical vs experimental strength

After an edge dislocation has passed through some region of a crystal, the atomic arrangement of that region is disordered. (a) True (b) False

How does the theoretical strength of a solid material compare with its experimental strength? (a) Strengththeoretical < strengthexperimental (b) Strengththeoretical = strengthexperimental (c) Strengththeoretical > strengthexperimental

Reserve Question 02: Dislocation motion The process by which plastic deformation is produced by dislocation motion is called ______.

Reserve Question 03: Edge dislocation movement Relative to the direction of an applied shear stress, the direction of motion of an edge dislocation’s line is (a) perpendicular. (b) parallel.

Reserve Question 04: Screw dislocation movement Relative to the direction of an applied shear stress, the direction of motion of a screw dislocation’s line is (a) perpendicular. (b) parallel.

Reserve Question 07: Edge dislocation strain The atoms surrounding an edge dislocation experience what kind(s) of strain(s)? (a) Shear strains (b) Tensile strains (c) Compressive strains

Reserve Question 08: Screw dislocation strain The atoms surrounding a screw dislocation experience what kind(s) of strain(s)? (a) Shear strains (b) Tensile strains (c) Compressive strains

Reserve Question 09: Ductility vs slip systems Reserve Question 05: Edge dislocation stress In response to an applied shear stress, an edge dislocation moves in which direction relative to its line? (a) Perpendicular (b) Parallel

A metal having a crystal structure with many operable slip systems will be relatively (a) ductile. (b) brittle.

Reserve Questions and Problems • R-49 Reserve Question 10: Slip direction

Reserve Problem 15a (question pool)

For a particular crystal structure, the slip direction is that direction in the slip plane having the (a) lowest linear density. (b) highest linear density.

Each option below depicts a candidate slip plane and direction in a cubic crystal.

Reserve Question 11: Slip plane–atomic packing

Note: the loading axis is depicted with a BLACK dotted line and is always normal to a cube face. (a)

For a particular crystal structure, the slip plane is that plane having the (a) least dense atomic packing. (b) most dense atomic packing.

Which of the following slip system candidates is the least likely to exhibit slip?

Reserve Question 12: Slip planes Dislocations move with the same degree of ease on all crystallographic planes of atoms and in all crystallographic directions. (a) True (b) False

(b)

Reserve Question 13: Slip systems The slip system for a particular crystal structure is that crystallographic plane-direction combination for which atomic distortion accompanying the motion of a dislocation is (a) a minimum. (b) a maximum.

Reserve Problem 14 Determine the angles α, β, and γ that are listed in the cubic unit cell provided.

Enter the angles in degrees.

Note: You should be able to use basic facts about cube geometry and crystallographic convention to solve this, rather than elaborate direction cosine equations.

(c)

(d)

(e)

R-50 • Reserve Questions and Problems Reserve Problem 16a (question pool)

Reserve Problem 17a (question pool)

Each option below depicts a candidate slip plane and direction in a cubic crystal.

The figures below depict hypothetical room-temperature random polycrystalline grain structures (at the same magnification) for the same single-component metal.

Which of these structures is expected to provide the lowest yield stress? (a)

Which of the following slip system candidates is the least likely to exhibit slip?

Note: the loading axis is depicted with a BLACK dotted line and is always normal to a cube face. (a)

(b)

(b)

(c) (c)

(d)

(d) (e)

Reserve Questions and Problems • R-51 Reserve Question 18: Twinning and crystal structures Mechanical twinning occurs in metals having which type(s) of crystal structure(s)? (a) BCC (b) FCC (c) HCP

Reserve Question 19: Grain size vs mechanical properties How does grain size influence strength of a polycrystalline material? (a) Strengthfine-grained < strengthcourse-grained (b) Strengthfine-grained = strengthcourse-grained (c) Strengthfine-grained > strengthcourse-grained

Reserve Question 20: Grain size vs toughness Reducing the grain size of metal improves toughness. (a) true (b) false

Reserve Question 21: Dislocation density As dislocation density increases, the resistance to dislocation movement (a) increases. (b) decreases.

Reserve Question 22: Dislocation interactions On the average, dislocation-dislocation strain interactions are (a) repulsive. (b) attractive.

Reserve Question 23: Ductility vs strain hardening As a metal is strain hardened, its ductility (a) increases (b) decreases

Reserve Question 24: Strain hardening Most metals strain harden at room temperature. (a) true (b) false

Reserve Problem 25 It is necessary to select a metal alloy for an application that requires a yield strength of at least 345 MPa (50,000 psi) while maintaining a minimum ductility (%EL) of 20%. If the metal may be cold worked, decide which of the following are candidates: copper, brass, and a 1040 steel.

• Brass • Copper • 1040 steel

Reserve Problem 26 The average grain diameter and yield strength for a brass material were measured as a function of time at 650°C. Given the following yield strengths for the two specimens, compute the heat treatment time required at 650°C to give a yield strength of 100 MPa. Assume a value of 2 for n, the grain diameter exponent.

Time (min)

Yield Strength (MPa)

Grain Diameter (mm)

30

90

3.9 × 10−2

90

75

6.6 × 10−2

Reserve Question 27: Recovery During the recovery of a cold-worked material, which of the following statement(s) is (are) true? (a) Some of the internal strain energy is relieved. (b) All of the internal strain energy is relieved. (c) There is some reduction in the number of dislocations. (d) There is a significant reduction in the number of dislocations, to approximately the number found in the precold-worked state. (e) The electrical conductivity is recovered to its precold-worked state. (f) The thermal conductivity is recovered to its precold-worked state. (g) The metal becomes more ductile, as in its precold-worked state. (h) Grains with high strains are replaced with new, unstrained grains.

Reserve Question 28: Recrystallization During the recrystallization of a cold-worked material, which of the following statement(s) is (are) true? (a) Some of the internal strain energy is relieved. (b) All of the internal strain energy is relieved. (c) There is some reduction in the number of dislocations. (d) There is a significant reduction in the number of dislocations, to approximately the number found in the precold-worked state. (e) The electrical conductivity is recovered to its precold-worked state. (f) The thermal conductivity is recovered to its precold-worked state. (g) The metal becomes more ductile, as in its precold-worked state. (h) Grains with high strains are replaced with new, unstrained grains.

R-52 • Reserve Questions and Problems Reserve Question 29: Grain growth requirements

Reserve Question 33: Adhesive bonding

Grain growth must always be preceded by recovery and recrystallization. (a) True (b) False

The bonding forces between adhesive and adherend surfaces are thought to be (a) Electrostatic (b) Covalent (c) Chemical

Reserve Problem 30 A hypothetical metal alloy has a grain diameter of 2.4 × 10−2 mm. After a heat treatment at 575°C for 500 min, the grain diameter has increased to 7.3 × 10−2 mm. Compute the time required for a specimen of this same material (i.e., d0 = 2.4 × 10−2 mm) to achieve a grain diameter of 5.5 × 10−2 mm while being heated at 575°C. Assume the n grain diameter exponent has a value of 2.2.

Reserve Problem 31: Tensile strength vs numberaverage molecular weight I Tensile strengths and number-average molecular weights for two polymers are as follows: Tensile strength (MPa) 37.7 131

Number average molecular weight (g/mol) 36800 62400

Estimate the tensile strength (in MPa) for a numberaverage molecular weight of 51500 g/mol.

Reserve Problem 32: Tensile strength vs numberaverage molecular weight II Tensile strengths and number-average molecular weights for two polymers are as follows: Tensile strength (MPa) 138 184

Number average molecular weight (g/mol) 12600 28100

Estimate number average molecular weight (in g/mol) at a tensile strength of 141 Mpa.

Reserve Question 34: Anisotropy of drawing Deformation of a semicrystalline polymer by drawing produces which of the following? (a) Increase in strength in the direction of drawing. (b) Decrease in strength in the direction of drawing. (c) Increase in strength perpendicular to the direction of drawing. (d) Decrease in strength perpendicular to the direction of drawing.

Reserve Question 35: Tensile strength– Deformation How does deformation by drawing of a semicrystalline polymer affect its tensile strength? (a) Increases (b) Decreases

Reserve Question 36: Tensile strength– Degree of crystallinity How does increasing the degree of crystallinity of a semicrystalline polymer affect its tensile strength? (a) Increases (b) Decreases

Reserve Question 37: Tensile strength– Molecular weight How does increasing the molecular weight of a semicrysatlline polymer affect its tensile strength? (a) Increases (b) Decreases

CHAPTER 9 FAILURE Reserve Question 01: Intergranular/transgranular fracture types Which kind of fracture (ductile or brittle) is associated with each of the two crack propagation mechanisms?

• Intergranular ______ • Transgranular ______

Reserve Problem 02: Altering crack radii The fracture strength of glass may be increased by etching away a thin surface layer. It is believed that the etching may alter the surface crack geometry (i.e. reduce crack length and increase tip radius). Calculate the ratio of the etched and original crack tip radii if the fracture strength is increased by a factor of 7 when 28% of the crack length is removed.

Reserve Questions and Problems • R-53 Reserve Problem 03: Crack length in plane strain

Reserve Question 07: Plane strain plate fracture

A structural component in the shape of a flat plate 27.3 mm thick is to be fabricated from a metal alloy for which the yield strength and plane strain fracture toughness values are 535 MPa and 31.3 MPa-m1/2, respectively. For this particular geometry, the value of Y is 1.8. Assuming a design stress of 0.5 times the yield strength, calculate the critical length of a surface flaw.

A plate of an alloy steel has a plane-strain fracture toughness of 50 MPa-m1/2. If it is known that the largest surface crack is 0.5 mm long, and that the value of Y is 1.1, which of the following can be said about this plate when a tensile stress of 1200 MPa is applied? (a) The plate will definitely fracture. (b) The plate will definitely not fracture. (c) It is not possible to determine whether or not the plate will fracture.

Reserve Question 04: Effect of temp on fracture toughness

Reserve Question 08: Stress raisers

How would the plane strain fracture toughness of a metal be expected to change with rising temperature? (a) Increase (b) Decrease (c) Remain constant

Reserve Question 05: Factors in brittle polymers Which of the following factor(s) favor(s) brittle fracture in polymers? (a) Increasing in temperature. (b) Increasing in strain rate. (c) The presence of a sharp notch. (d) Decreasing specimen thickness.

Reserve Question 06: Fracture test–Charpy The results of a laboratory test that is used to assess the mechanical or failure characteristics of metals are shown below. Select labels for both of the plot axes.

X-axis: ______ Y-axis: ______

The effect of a stress raiser is more significant for which of the following types of materials? (a) Brittle materials (b) Ductile materials

Reserve Problem 09 A structural component is fabricated from an alloy that has a plane strain fracture toughness of 45 MPa. It has been determined that this component fails at a stress of 300 MPa when the maximum length of a surface crack is 0.95 mm. What is the maximum allowable surface crack length (in mm) without fracture for this same component exposed to a stress of 300 MPa and made from another alloy with a plane strain fracture toughness of 100.0 MPa? The geometry factor Y is the same in both cases.

Reserve Problem 10 Following are tabulated data that were gathered from a series of Charpy impact tests on a ductile cast iron.

Temperature ( °C)

Impact Energy (J)

−25 −50 −75 −85 −100 −110 −125 −150 −175

124 123 115 100 73 52 26 9 6

(a) Determine a ductile-to-brittle transition temperature as that temperature corresponding to the average of the maximum and minimum impact energies. (b) Determine a ductile-to-brittle transition temperature as that temperature at which the impact energy is 80 J.

R-54 • Reserve Questions and Problems Reserve Problem 11

Reserve Problem 14a (question pool)

Following are tabulated data that were gathered from a series of Charpy impact tests on a tempered 4140 steel alloy.

The figure below depicts a brittle material featuring four elliptical flaws, each featuring the same radius of curvature at their tips. Based on the loading type and the loading axis illustrated, which flaw is most likely to propagate?

Temperature ( °C)

Impact Energy (J)

100

89.3

75

88.6

50

87.6

25

85.4

0

82.9

−25

78.9

−50

73.1

−65

66.0

−75

59.3

−85

47.9

−100

34.3

−125

29.3

−150

27.1

−175

25.0

(a) Determine a ductile-to-brittle transition temperature as that temperature corresponding to the average of the maximum and minimum impact energies. (b) Determine a ductile-to-brittle transition temperature as that temperature at which the impact energy is 70 J.

Reserve Question 15: Fracture test–Tensile The results of a laboratory test that is used to assess the mechanical or failure characteristics of metals are shown below. Select labels for both of the plot axes.

Reserve Problem 12 What is the maximum carbon content possible for a plain carbon steel that must have an impact energy of at least 150 J at 0°C?

Reserve Problem 13 Compute the minimum value of plane-strain fracture toughness required of a material to satisfy the leakbefore-break criterion for a cylindrical pressure vessel similar to that shown in Figure 9.11. The vessel radius and wall thickness values are 250 mm and 10.5 mm, respectively, and the fluid pressure is 3.0 MPa. Assume a value of 3.5 for the factor of safety.

X-axis ______ Y-axis ______

Reserve Questions and Problems • R-55 Reserve Question 16: Fracture test–fatigue

Reserve Question 19: Creep behavior

The results of a laboratory test that is used to assess the mechanical or failure characteristics of metals are shown below. Select labels for both of the plot axes.

Match each of the three stages of creep behavior with the manner in which creep rate changes with increasing time.

Primary (transient creep) • Decreasing creep rate • Constant creep rate • Increasing creep rate Secondary creep • Decreasing creep rate • Constant creep rate • Increasing creep rate Tertiary creep • Decreasing creep rate • Constant creep rate • Increasing creep rate

X-axis ______ Y-axis ______

Reserve Question 20: Fracture test–creep

Reserve Problem 17 A cylindrical rod of diameter 9.5 mm fabricated from a 2014-T6 aluminum alloy is subjected to rotatingbending load cycling; test results (as S-N behavior) are shown in Figure 9.27. If the maximum and minimum loads are +400 N and –400 N, respectively, determine its fatigue life. Assume that the separation between loadbearing points is 72.5 mm.

The results of a laboratory test that is used to assess the mechanical or failure characteristics of metals are shown below. Select labels for both of the plot axes.

Reserve Problem 18 (a) Compare the fatigue limits for polystyrene (Figure 9.29) and the cast iron for which fatigue data are given in the table below: Stress Amplitude [MPa (ksi)]

Cycles to Failure

X-axis: ______ Y-axis: ______

248 (36.0)

1 × 105

Reserve Question 21: Creep elongation

236 (34.2)

3 × 105

224 (32.5)

1 × 106

213 (30.9)

3 × 106

201 (29.1)

1 × 107

A specimen 667 mm long of a low carbon-nickel alloy is to be exposed to a tensile stress of 37 MPa at 538°C. Using the Animated Figure 9.40, determine its elongation after 5300 hours. Assume that the total of both instantaneous and primary creep elongations is 1.5 mm.

193 (28.0)

3 × 107

193 (28.0)

1 × 108

193 (28.0)

3 × 108

(b) Compare the fatigue strengths at 106 cycles for poly(ethylene terephthalate) (PET, Figure 92.9) and 70Cu–30Zn brass (Figure 9.27).

Reserve Question 22: Creep tensile load For a cylindrical low carbon-nickel alloy specimen originally 11 mm in diameter and 503 mm long, what tensile load (in N) is necessary to produce a total elongation of 4.8 mm after 19000 hours at 538°C? Assume that the sum of instantaneous and primary creep elongations is 0.86 mm. The logarithm stress versus logarithm of steady-state creep rate plot for this alloy is in the Animated Figure 9.40.

R-56 • Reserve Questions and Problems Reserve Question 23: Factors affecting creep

Reserve Problem 26

Which of the following affect(s) the creep characteristics of metals? (a) Melting temperature

(d) Ductility

A cylindrical component 75 mm long constructed from an S-590 alloy (Figure 9.40) is to be exposed to a tensile load of 20,000 N. What minimum diameter is required for it to experience an elongation of no more than 10.2 mm after an exposure for 1250 h at 815°C? Assume that the sum of instantaneous and primary creep elongations is 0.7 mm.

(e) Elastic modulus

Reserve Problem 27

(f) Resilience

A cylindrical specimen 7.5 mm in diameter of an S-590 alloy is to be exposed to a tensile load of 9000 N. At approximately what temperature will the steadystate creep be 10−2 h−1?

(b) Grain size (c) Yield strength

Reserve Question 24: Increasing stress or temperature If either stress or temperature is increased, indicate which of the following consequences will result. (a) The instantaneous strain at the time of stress application decreases. (b) The steady-state creep rate increases. (c) The rupture lifetime is diminished.

Reserve Question 25: Temperature for creep Above about what temperature does the creep become an important failure mechanism for a metal? (a) 0.1Tm (b) 0.2Tm (c) 0.3Tm (d) 0.4Tm (e) 0.5Tm

Reserve Problem 28 If a component fabricated from an S-590 alloy (Figure 9.39) is to be exposed to a tensile stress of 300 MPa (43,500 psi) at 650°C (1200°F), estimate its rupture lifetime.

Reserve Problem 29 A cylindrical component constructed from an S-590 alloy (Figure 9.39) is to be exposed to a tensile load of 10,000 N. What minimum diameter is required for it to have a rupture lifetime of at least 10 h at 730°C?

Reserve Problem 30 (a) Using Figure 9.39, compute the rupture lifetime for an S-590 alloy that is exposed to a tensile stress of 100 MPa at 925°C. (b) Compare this value to the one determined from the Larson-Miller plot of Figure 9.41, which is for this same S-590 alloy.

CHAPTER 10 PHASE DIAGRAMS Reserve Problem 01 The mineral olivine is a solid solution of the silicate compounds forsterite (Mg2SiO4) and fayalite (Fe2SiO4).

How many chemical components are there in a sample of olivine?

(a) 1 (b) 2 (c) 3 (d) 4

Reserve Questions and Problems • R-57 Reserve Problem 02a (question pool) Which of the following depictions is consistent with a single-component, single-phase 2D crystalline system? (a)

(d)

(b) (e)

(c)

Reserve Problem 03 Seawater, which covers the majority of the earth, is composed primarily of molecules of H2O and equal numbers of Na+ ions and Cl− ions. Suppose we have a thoroughly mixed solution (containing these species only) at 25oC. How many components and how many phases are in such a system? (a) 1 component, 1 phase

(f)

(g) 2 component, 3 phase (h) 2 component, 4 phase (i) 3 component, 1 phase (j) 3 component, 2 phase (k) 3 component, 3 phase (l) 3 component, 4 phase

(b) 1 component, 2 phase

(m) 4 component, 1 phase

(c) 1 component, 3 phase

(n) 4 component, 2 phase

(d) 1 component, 4 phase

(o) 4 component, 3 phase

(e) 2 component, 1 phase

(p) 4 component, 4 phase

(f) 2 component, 2 phase

R-58 • Reserve Questions and Problems Reserve Problem 04

Reserve Problem 08

Select all of the two-phase material systems from the list below. Select all that apply. (a) Solid ductile cast iron (ferrite solid solution + embedded graphite spheres)

At a pressure of 0.01 atm, determine (a) the melting temperature for ice, and (b) the boiling temperature for water.

(b) Solid sodium chloride (salt, NaCl) (c) Liquid bronze (Cu + Sn liquid solution) (d) Solid gray cast iron (ferrite solid solution + embedded graphite flakes) (e) Solid aluminum featuring dissolved silicon (f) Solid lead-tin solder (a mixture of Pb-rich and Sn-rich solid solutions) (g) Partially melted aluminum (h) Frozen water with trapped air bubbles (i) Epoxy embedded with carbon fibers

Reserve Problem 05 Complete the following statements regarding conditions that must be satisfied in order for a solid solution to exhibit extensive solubility.

Reserve Question 09: Liquidus line A liquidus line separates which of the following combinations of phase fields? (a) Liquid and Liquid + α (b) α and Liquid + α (c) α and α + β (d) Liquid + α and α + β

Reserve Question 10: Solvus line A solvus line separates which of the following pairs of phase fields? (a) Liquid and Liquid + α (b) α and Liquid + α (c) α and α + β (d) Liquid + α and α + β

The solute and host species must have very [w] sizes.

Reserve Problem 11

The solute and host species must attempt to pack with [x] crystal structure.

How many kilograms of nickel must be added to 5.66ks of copper to yield a liquidus temperature of 1200°C? Use Animated Figure 10.3a.

The solute and host species must feature [y] valence electron configuration.

The solute and host species must feature [z] ability to attract electrons (electronegativity). w = similar, different x = a similar (or the same), a different y = a similar (or the same), a different z = a similar, a different

Reserve Question 06: Solvent/solute For a solution, which of the following is present in the higher concentration? (a) Solvent (b) Solute

Reserve Problem 07 Consider a specimen of ice that is at −10°C and 1 atm pressure. Using Figure 10.2, the pressure–temperature phase diagram for H2O, determine the pressure to which the specimen must be raised or lowered to cause it (a) to melt, and (b) to sublime.

Reserve Question 12: Information on phase diagrams Which of the following kinds of information may be determined with the aid of a phase diagram? (a) The phase(s) present at a specified temperature and composition. (b) The composition(s) of phase(s) present at a specified temperature and composition. (c) The fraction(s) of phase(s) present at specified temperature and composition.

Reserve Questions and Problems • R-59 Reserve Problem 13: Pb-Sn phase diagram– composition In the Animated Figure 10.8 is shown the lead-tin phase diagram. For an alloy of composition 25 wt% Sn–75 wt% Pb, select the phase(s) present and their composition(s) for each of the temperatures cited. (a) 300°C? • L = 25.0 wt% Sn–75.0 wt% Pb • L = 25.0 wt% Sn–75.0 wt% Pb; α = 10.0 wt% Sn–90.0 wt% Pb • L = 10.0 wt% Sn–90.0 wt% Pb; α = 10.0 wt% Sn–90.0 wt% Pb • L = 90.0 wt% Sn–10.0 wt% Pb; α = 10.0 wt% Sn–90.0 wt% Pb (b) 200°C? • α = 17.0 wt% Sn–83.0 wt% Pb; L = 55.7 wt% Sn–44.3 wt% Pb • α = 17.0 wt% Sn–83.0 wt% Pb; β = 55.7 wt% Sn–44.3 wt% Pb • α = 18.3 wt% Sn–81.7 wt% Pb; β = 97.8 wt% Sn–2.2 wt% Pb • L = 25.0 wt% Sn–75.0 wt% Pb; α = 25.0 wt% Sn–75.0 wt% Pb (c) 183°C? • α = 25.0 wt% Sn–75.0 wt% Pb; β = 25.0 wt% Sn–75.0 wt% Pb • L = 25.0 wt% Sn–75.0 wt% Pb; α = 25.0 wt% Sn–75.0 wt% Pb; β = 25.0 wt% Sn–75.0 wt% Pb • α = 18.3 wt% Sn–81.7 wt% Pb; β = 97.8 wt% Sn–2.2 wt% Pb • L = 61.9 wt% Sn–38.1 wt% Pb; α = 18.3 wt% Sn–81.7 wt% Pb; β = 97.8 wt% Sn–2.2 wt% Pb (d) 100°C? • α = 25.0 wt% Sn–75.0 wt% Pb; β = 25.0 wt% Sn–75.0 wt% Pb • L = 25.0 wt% Sn–75.0 wt% Pb; α = 25.0 wt% Sn–75.0 wt% Pb; β = 25.0 wt% Sn–75.0 wt% Pb • α = 5.1 wt% Sn–94.9 wt% Pb; β = 98.7 wt% Sn–1.3 wt% Pb • L = 25.0 wt% Sn–75.0 wt% Pb; α = 5.1 wt% Sn–94.9 wt% Pb; β = 98.7 wt% Sn–1.3 wt% Pb

Reserve Problem 14: Pb-Sn phase diagram–Phases In Animated Figure 10.8 is shown the lead-tin phase diagram. Using this diagram, determine which of the following phase(s)/phase combination(s) (alpha, beta, liquid, alpha + liquid, beta + liquid, alpha + beta, and alpha + beta + liquid) will be present for an alloy of composition 61.9 wt% Sn–38.1 wt% Pb that is at equilibrium at 185°C?

Reserve Question 15: Phases present at eutectic point At a eutectic point on a binary temperature-composition phase diagrams, how many phases are present when the system is at equilibrium? (a) 0 (c) 2 (b) 1 (d) 3

Reserve Problem 16 A 45 wt% Pb–55 wt% Mg alloy is rapidly quenched to room temperature from an elevated temperature in such a way that the high-temperature microstructure is preserved. This microstructure is found to consist of the phase and Mg2Pb, having respective mass fractions of 0.65 and 0.35. Determine the approximate temperature from which the alloy was quenched.

Reserve Problem 17 Two intermetallic compounds, AB and AB2, exist for elements A and B. If the compositions for AB and AB2 are 34.3 wt% A–65.7 wt% B and 20.7 wt% A–79.3 wt% B, respectively, and element A is potassium, identify element B. • Phosphorus • Sulfur • Arsenic • Antimony

Reserve Problem 18 An intermetallic compound is found in the magnesiumgallium system that has a composition of 41.1 wt% Mg–58.9 wt% Ga. Specify the formula for this compound.

• MgGa • Mg2Ga • MgGa2 • Mg3Ga2

R-60 • Reserve Questions and Problems Reserve Problem 19

Reserve Problem 23

Specify the liquidus, solidus, and solvus temperatures for the following alloy: 1.5 wt% C – 98.5 wt% Fe. If no temperature, please put in “0.0”.

Liquidus temperature ______ Solidus temperature ______ Solvus temperature ______

Specify the number of degrees of freedom for the following alloys: (a) 95 wt% Ag-5 wt% Cu at 780°C (b) 80 wt% Ni-20 wt% Cu at 1400°C (c) 44.9 wt% Ti-55.1 wt% Ni at 1310°C (d) 61.9 wt% Sn-38.1 wt% Pb at 183°C (e) 2.5 wt% C-97.5 wt% Fe at 1000°C

Reserve Question 20: Eutectoid reaction A eutectoid reaction involves which of the following phases? (a) One liquid and one solid (b) One liquid and two solid (c) Two liquids and one solid (d) Three solid

Reserve Question 21: Peritectic reaction A peritectic reaction involves which of the following combinations of phase fields? (a) One liquid and one solid (b) One liquid and two solid (c) Two liquids and one solid (d) Three solid

Reserve Question 22: Congruent transformations For a congruent phase transformation there are (a) no composition alterations. (b) compositional alterations.

Reserve Problem 24 The mass fractions of total ferrite and total cementite in an iron–carbon alloy are 0.88 and 0.12, respectively.

Is this a hypoeutectoid or hypereutectoid alloy?

Reserve Problem 25 A steel alloy is known to contain 93.8 wt% Fe, 6.0 wt% Ni, and 0.2 wt% C. Assume that there are no alterations in the positions of other phase boundaries with the addition of Ni. (a) What is the approximate eutectoid temperature of this alloy? (b) What is the proeutectoid phase when this alloy is cooled at temperature below the eutectoid? (c) Compute the relative amounts of the proeutectoid phase and pearlite.

CHAPTER 11 PHASE TRANSFORMATIONS Reserve Problem 01 It is known that the kinetics of some transformation obeys the Avrami equation and that the value of k is 6.0 × 10−8 (for time in minutes). If the fraction transformed is 0.75 after 200 min, determine the rate of this transformation.

Diffusion-dependent with no change(s) in phase composition(s) • Eutectoid reaction • Recrystallization • Martensitic transformation

Reserve Question 02: Types of phase transformations Match each transformation description below with name of a transformation of this type.

Reserve Question 03: Equilibrium in solid

Diffusion-dependent with change(s) composition(s) • Martensitic transformation • Eutectoid reaction • Recrystallization

Equilibrium structures are commonly achieved in solid systems. (a) True (b) False

Diffusionless • Recrystallization • Martensitic transformation • Eutectoid reaction

in

phase

Reserve Question 04: Heat treatment Below is shown the isothermal transformation diagram for a 0.45 wt% C iron-carbon alloy. List the microconstituent(s) present for the heat treatment labeled (a) on this diagram. It is not necessary to state the proportion(s) of the microconstituents.

Reserve Questions and Problems • R-61 900 1600

Temperature (°C)

700

(a)

A+F

300

1400

(c) P B (c)

600 500 (b) 400

(a)

(c)

A

1200

A+P 1000 A+B

(b)

(c) 50%

800

M(start) M(50%)

(b)

(c)

600 (b)

M(90%)

400

200 100 0 0.1

Temperature (°F)

800

200

(b) 1

(c) 10

102

103

(a) 104

(a) How long will it take for the austeniteto pearlite reaction to go to 50% completion?

To 100% completion?

50% completion: ______ 100% completion: ______ (b) Estimate the hardness of the alloy that has completely transformed to pearlite.

Reserve Question 06: Fe microstructures I Schematic room temperature microstructures for four iron-carbon alloys are shown below. Rank these alloy microstructures (by letter) from most ductile to the least ductile.

Fe3C

Fe3C

(b) 105

Time (s)

Reserve Problem 05 Suppose that a steel of eutectoid composition is cooled to 550°C (1020°F) from 760°C (1400°F) in less than 0.5 s and held at this temperature.

𝛼

𝛼 Fe3C (A)

(B)

(a) C, D, A, B (b) B, D, A, C (c) A, B, D, C (d) D, B, C, A

𝛼

Fe3C

Fe3C

𝛼 𝛼

Fe3C (C)

(D)

(e) C, A, B, D (f) B, A, D, C (g) A, B, C, D (h) D, C, B, A

CHAPTER 12 ELECTRICAL PROPERTIES Reserve Problem 01

Reserve Question 03: Conductivities

Select the word combination that best completes this statement.

Match each of the conductivity values/ranges with its associated class of materials.

Electric current is a measure of [a] _______ passing per unit [b]_______, and the base units of current are [c]______ per [d]______, otherwise known as an [e]_______.

• Time • Volts • Ampere • Resistance • Second • Ohm • Charge • Coulomb • Voltage

10−20 to 10−10 (Ω-m)−1 • Semiconductors

Reserve Problem 02a (question pool) The current-voltage behavior of specimens [a]–[e] is depicted in the figure below.

Which of these specimens features the lowest resistance?

• Metals • Insulators 107 (Ω-m)−1 • Metals • Insulators • Semiconductors 10−6 to 104 (Ω-m)−1 • Insulators • Semiconductors • Metals

R-62 • Reserve Questions and Problems Reserve Question 04: Band structures Match each of the following energy band structures with the type of material it represents.

(A) Empty conduction band

Band gap

Filled valence band

• Semiconductor • Metal • Insulator (B) Empty conduction band Band gap Filled valence band

• Metal • Insulator • Semiconductor

Reserve Question 06: Energy name ______ energy is the name of energy corresponding to the highest filled electron state at 0 K.

Reserve Question 07: Free electrons 01 Are energies for electrons that participate in the conduction process (i.e., free electrons) greater or less than the Fermi energy? (a) Greater than (b) Less than

Reserve Question 08: Holes Are energies for holes greater or less than the Fermi energy? (a) Greater than (b) Less than

Reserve Question 09: Insulator band gap An insulator has an energy band gap that is relatively (a) wide. (b) narrow.

Reserve Question 10: P band For a material that contains N atoms, how many electron states will there be in a p band?

Reserve Question 11: S band For a material that contains N atoms, how many electron states will there be in an s band?

Reserve Question 12: Semiconductor band gap

(C) Empty band

Band gap Empty states Filled states

• Insulator • Semiconductor • Metal

Reserve Question 05: Electrons for conductivity All electrons present in a material are available to participate in the conduction process. (a) True (b) False

A semiconductor has an energy band gap that is relatively (a) wide (b) narrow

Reserve Question 13: Free electrons in metals Electrons in metals do not require any excitation before becoming conduction electrons that are free. (a) True (b) False

Reserve Question 14: Temperature vs band gap For nonmetallic materials, which of the following is true? (a) The wider the band gap, the lower the electrical conductivity at a given temperature. (b) The wider the band gap, the higher the electrical conductivity at a given temperature.

Reserve Questions and Problems • R-63 Reserve Question 15: Current in perfect crystal

Reserve Question 20: Resistivity contributions

In a perfect crystal (i.e., without any imperfections), application of an electric field will result in a continuously increasing electric current with time. (a) True (b) False

Which of the following have a significant influence on a material’s electrical resistivity? (a) impurity concentration (b) temperature (c) grain size (d) cold work (e) vacancy concentration

Reserve Question 16: Electric field induced electron movement When an electric field is applied, in which direction are the free electrons accelerated? (a) Opposite to the direction of the electric field. (b) In the same direction as the electric field.

Reserve Question 17: Ion mobility At temperatures between 775°C and 1100°C, the activation energy and preexponential for the diffusion coefficient of A2+ in the metal oxide, AO, are 110 kJ/ mol and 7.1 × 10−7 m2/s, respectively. Compute the mobility [in m2/(V-s)] of A2+ at 908°C.

Reserve Problem 21 (a) Using the data in Figure 12.8, determine the values of ρ0 and a from Equation 12.10 for pure copper. Take the temperature T to be in degrees Celsius. (b) Determine the value of A in Equation 12.11 for nickel as an impurity in copper, using the data in Figure 12.8. (c) Using the results of parts (a) and (b), estimate the electrical resistivity of copper containing 1.75 at% Ni at 100°C.

Reserve Problem 22

Reserve Problem 18: Calculating resistivity contributions

Conductivity in a metal is almost always reduced by the introduction of defects into the lattice.

Estimate the electrical resistivity (in Ω-m) of metal Y containing 1.3 at% of metal Z at 138°C, given the following data: ρ0 (Ω-m)

a (Ω-m/°C)

A (Ω-m)

The factor primarily affected by defects is: (a) free electron concentration (b) electron charge (c) electron mobility (d) electron spin

1.5 × 10−7

6.7 × 10−11

1.2 × 10−6

Reserve Problem 23a (question pool)

Assume that all of the 1.3 at% of metal Z goes into solid solution in metal Y. Use scientific notation.

Compute the number of electrons that each aluminum atom donates, on average, to a bulk piece of aluminum metal. Room temperature data for aluminum: The resistivity of aluminum is 2.63 × 10−8 Ω-m

Reserve Problem 19: Multi-component conductivity

The electron mobility of aluminum is 0.0012 m2/(V-s)

Some two-phase metal alloy is known to be composed of α and β phases; mass fractions of these phases are 0.74 and 0.26, respectively. Room-temperature electrical resistivity and density data for these phases are tabulated below. Using this information, calculate the electrical resistivity (in Ω-m) of the alloy at room temperature (use scientific notation).

The mass density of aluminum is 2.7 g/cm3 The atomic weight of aluminum is 27 g/mol

Reserve Problem 24 Compute the number of electrons that each atom donates, on average, to a bulk piece of hypothetical metal. Room temperature data for the metal: The resistivity of the metal is [r] Ω-cm

Phase

Resistivity (Ω-m)

Density (g/cm2)

α

1.7 × 10−7

8.31

The electron mobility of the metal is [m] cm2/(V-s)

β

6.7 × 10−8

8.18

The mass density of the metal is [d] g/cm3 The atomic weight of the metal is [w] g/mol

R-64 • Reserve Questions and Problems Reserve Question 25: Electric field induced hole movement

Reserve Question 32: n-type semiconductor– Conduction

When an electric field is applied, in which direction are the free electrons accelerated? (a) Opposite to the direction of the electric field. (b) In the same direction as the electric field.

For an n-type semiconductor, which type of charge carrier is present in the greater concentration? (a) Hole (b) Electron

Reserve Question 26: Intrinsic semiconductor

Reserve Question 33: n-type semiconductor– electrons/holes

The electrical conductivity of an intrinsic semiconductor is (a) characteristic of the high-purity metal. (b) due to the presence of impurities.

For an n-type semiconductor (a) Concentrationelectrons > concentrationholes (b) Concentrationelectrons = concentrationholes (c) Concentrationelectrons < concentrationholes

Reserve Question 27: Metals vs semiconductors

Reserve Question 34: p-type semiconductor– conduction

How do the electrical conductivities of metals compare with those of semiconductors? (a) σmetals > σsemiconductors (b) σmetals = σsemiconductors (c) σmetals < σsemiconductors

Reserve Question 28: Temperature vs electron/ hole concentrations–Intrinsic How does increasing temperature affect the concentration of both electrons and holes in an intrinsic semiconductor? (a) Increases the concentration. (b) Decreases the concentration. (c) May increase and/or decrease the concentration, depending on the temperature range.

Reserve Question 29: Acceptor impurity Which type of charge carrier will be introduced into a semiconductor by the presence of an acceptor impurity? (a) Electron (b) Hole

Reserve Question 30: Donor impurity Which type of charge carrier will be introduced into a semiconductor by the presence of a donor impurity? (a) Impurity (b) Hole

For a p-type semiconductor, which type of charge carrier is present in the greater concentration? (a) Hole (b) Electron

Reserve Question 35: p-type semiconductor– electrons/holes For a p-type semiconductor (a) Concentrationelectrons > concentrationholes (b) Concentrationelectrons = concentrationholes (c) Concentrationelectrons < concentrationholes

Reserve Question 36: Required impurity concentrations In order for a semiconductor to exhibit extrinsic electrical characteristics, relatively high impurity concentrations are required. (a) True (b) False

Reserve Problem 37 The following electrical characteristics have been determined for both intrinsic and n-type extrinsic indium phosphide (InP) at room temperature: σ (Ω∙m)−1

n (m−3)

p (m−3)

Intrinsic

2.5 × 10−6

3.0 × 1013

3.0 × 1013

Extrinsic (n-type)

3.6 × 10−5

4.5 × 1014

2.0 × 1012

Calculate electron and hole mobilities. μe = ______ μh = ______

Reserve Question 31: Extrinsic semiconductor

Reserve Question 38: Semiconducting devices

The electrical conductivity of an extrinsic semiconductor is (a) characteristic of the high-purity material. (b) due to the presence of impurities.

Which of the following are preferred for semiconducting devices? (a) Single crystals (b) Polycrystalline materials

Reserve Questions and Problems • R-65 Reserve Problem 39

Reserve Question 40: Temperature vs conductivity

Which of the following current-voltage plots is consistent with the behavior of a p-n junction?

As temperature increases, the electrical conductivities of polymers and ionic ceramics (a) Increase (b) Decrease

(a)

Reserve Question 41: Band gap of ionic ceramics/ polymers

(b)

Most polymers and ionic ceramics have energy band gap structures that are most similar to those of (a) Insulators (b) Semiconductors (c) Metals

Reserve Question 42: Charge carriers in ionic ceramics/polymers

(c)

The charge carriers in ionic ceramics and polymers can be (a) Electrons (b) Holes (c) Anion (d) Cations

Reserve Problem 43: Capacitor calculations I

(d)

Consider a parallel-plate capacitor having an area of 2300 mm2 and a plate separation of 3.6 mm, and with a material of dielectric constant 5.8 positioned between the plates. Also, the value of ε0 is 8.85 × 10−12 F/m. (a) What is the capacitance of this capacitor? (b) Compute the electric field that must be applied for a charge of 8.8 × 10−9 C to be stored on each plate.

Reserve Problem 44: Capacitor spacing

(e)

A parallel-plate capacitor using a dielectric material having an εr of 2.8 has a plate spacing of 2.6 mm. If another material having a dielectric constant of 4.5 is used and the capacitance is to not change, what is the new spacing between the plates? The value of ε0 is 8.85 × 10−12 F/m.

R-66 • Reserve Questions and Problems

CHAPTER 13 TYPES AND APPLICATIONS OF MATERIALS Reserve Question 01: Alloy designations I

Reserve Question 08: Cast irons–Typical C

Which type of steel has the designation 4330? (a) Plain carbon steel (b) Alloy steel

Which of the following is the typical range of carbon concentrations for cast iron? (a) 1.0 wt%–1.5 wt% C (b) 1.0 wt%–2.0 wt% C (c) 2.0 wt%–3.0 wt% C (d) 2.0 wt%–3.5 wt% C (e) 3.0 wt%–4.0 wt% C (f) 3.0 wt%–4.5 wt% C

Reserve Question 02: Alloy designations II Which type of steel has the designation 1015? (a) Plain carbon steel (b) Alloy steel

Reserve Question 03: Alloy designations III What is the carbon concentration of a steel having designation 1050? (a) 0.01 wt% C (d) 0.50 wt% C (b) 0.05 wt% C (e) Impossible to say (c) 0.10 wt% C

Reserve Question 04: Alloying elements–stainless steels Which three elements in the list below are primary alloying elements for the stainless steels? (a) Copper (e) Chromium (b) Vanadium (f) Tungsten (c) Nickel (g) Silicon (d) Molybdenum

Reserve Question 05: Carbon constituent in white cast iron In what form is carbon found in white cast irons? (a) Cementite (b) Graphite

Reserve Question 06: Carbon steel strength Which of the sequences below represents the various steels types in order of decreasing hardness? (a) High-carbon > Medium-carbon > Low-carbon (b) High-carbon > Low-carbon > Medium-carbon (c) Medium-carbon > High-carbon > Low-carbon (d) Medium-carbon > Low-carbon > High-carbon (e) Low-carbon > High-carbon > Medium-carbon (f) Low-carbon > Medium-carbon > High-carbon

Reserve Question 07: Cast irons–Minimum C Which of the following is the minimum carbon content for cast irons? (a) 1.0 wt% C (d) 2.14 wt% C (b) 1.56 wt% C (e) 3.42 wt% C (c) 2.00 wt% C (f) 4.96 wt% C

Reserve Question 09: Cold worked stainless steels Which of the following stainless steel types may be strengthened/hardened only by cold working? (a) Ferritic (b) Martensitic (c) Austenitic Reserve Question 10: Conversion of gray to nodular irons Which two of the following elements may be added to gray irons before casting so as to produce ductile (or nodular) irons? (a) Silicon (c) Serium (b) Magnesium (d) Molybdenum Reserve Question 11: Corrosion resistance: low-carbon vs HSLA steels Which type of steel has the greater resistance to corrosion? (a) plain low-carbon (b) high-strength, low-alloy

Reserve Question 12: Disadvantages of ferrous alloys Which of the following factors restrict(s) the use of ferrous alloys? (a) Poor corrosion resistance. (b) Poor mechanical properties. (c) Ores containing iron are rare. (d) Costly and difficult to process.

Reserve Question 13: Ferrous alloy structures All ferrous alloys have similar microstructures. (a) True (b) False

Reserve Questions and Problems • R-67 Reserve Question 14: Ferrous alloys

Reserve Question 21: Magnetic stainless steels

______ is the primary constituent of ferrous alloys.

Which of the following stainless steel types may be magnetized? (a) Ferritic (b) Martensitic (c) Austenitic

Reserve Question 15: Gray iron structures Which of the following microconstituents/phases is (are) most commonly found in gray cast irons? (a) Graphite (d) Austenite (b) Pearlite (e) Martensite (c) Ferrite

Reserve Question 16: Heat-treatable stainless steels 01 Which of the following types of stainless steels may be heat treated to improve their mechanical properties? (a) Ferritic (d) Austenitic (b) Pearlitic (e) Precipitation-hardenable (c) Martensitic

Reserve Question 17: Heat treatment of low-carbon steels The strengths of typical low-carbon steels are often improved by heat treatment. (a) True (b) False

Reserve Question 18: High-carbon steels What is the range of carbon concentrations for highcarbon steels? (a) 0.40 wt%–1.0 wt% C (b) 0.50 wt%–1.1 wt% C (c) 0.50 wt%–1.4 wt% C (d) 0.65 wt%–1.4 wt% C (e) 0.65 wt%–1.7 wt% C

Reserve Question 19: Low-carbon steel structures Which of the following microconstituent(s)/phase(s) is (are) typically found in a low-carbon steel? (a) Ferrite (d) Austenite (b) Pearlite (e) Tempered martensite (c) Martensite

Reserve Question 20: Low-carbon steels Which of the following is the typical carbon concentration for a low-carbon steel? (a) 0.05 wt% C (d) 0.50 wt% C (b) 0.10 wt% C (e) 0.75 wt% C (c) 0.25 wt% C (f) 1.00 wt% C

Reserve Question 22: Mechanical properties of white cast irons Which of the following characteristics best describe the mechanical properties of white cast irons? (a) Hard (c) Ductile (b) Weak (d) Brittle

Reserve Question 23: Medium-carbon steel structures Which of the following microconstituents/phases is typically found in a medium-carbon steel? (a) Ferrite (d) Austenite (b) Pearlite (e) Tempered martensite (c) Martensite

Reserve Question 24: Medium-carbon steels What is the typical carbon concentration range for medium-carbon steels? (a) 0.05 wt%–1.00 wt% C (b) 0.10 wt%–0.50 wt% C (c) 0.25 wt%–0.65 wt% C (d) 0.25 wt%–1.00 wt% C (e) 0.50 wt%–0.75 wt% C

Reserve Question 25: Melting Which of the following ferrous alloy types is most easily melted? (a) Cast irons (b) Low-carbon steels (c) Medium-carbon steels (d) High-carbon steels (e) Stainless steels

Reserve Question 26: Metal alloy production Which metal alloy type is produced in the greatest quantities? (a) Ferrous (b) Copper (c) Aluminum (d) Titanium

R-68 • Reserve Questions and Problems Reserve Question 27: Most common steels Which of the following steel types is produced in the greatest quantities? (a) Low-carbon (b) Medium-carbon (c) High-carbon

Reserve Question 28: Nodular iron structures Which of the following microconstituents/phases are generally found in nodular irons? (a) Graphite (b) Pearlite (c) Ferrite (d) Austenite (e) Martensite

Reserve Question 29: Types of steels Which type of steel contains only residual amounts of alloying elements? (a) Plain carbon steel (b) Alloy steel

Reserve Question 30: white cast irons vs malleable irons Which of the following changes occur(s) when white cast irons are converted to malleable irons? (a) The cementite is converted into graphite. (b) The graphite is converted into cementite. (c) The ductility increases. (d) The ductility remains about the same. (e) The ductility decreases.

Reserve Question 31: Alloy selection For each of the following applications, match the metal or alloy that is most suitable.

Milling machine base • Titanium alloy • Plain carbon steel • Tool steel • Zinc • Tungsten

• Aluminum • Platinum • Gray cast iron • Stainless steel • Brass

Walls of steam boiler • Plain carbon steel • Tool steel • Zinc • Tungsten • Aluminum

• Platinum • Gray cast iron • Stainless steel • Brass • Titanium alloy

High-speed aircraft • Brass • Stainless steel • Gray cast iron • Platinum • Aluminum

• Tungsten • Zinc • Tool steel • Plain carbon steel • Titanium alloy

Drill bit • Titanium alloy • Brass • Stainless steel • Gray cast iron • Platinum

• Aluminum • Tungsten • Zinc • Tool steel • Plain carbon steel

Cryogenic (very low temperature) container • Aluminum • Titanium alloy • Platinum • Plain carbon steel • Gray cast iron • Tool steel • Stainless steel • Zinc • Brass • Tungsten Pyrotechnic (i.e., flares or fireworks) • Tungsten • Aluminum • Zinc • Brass • Tool steel • Stainless steel • Plain carbon steel • Gray cast iron • Titanium alloy • Platinum High-temperature furnace elements to be used in oxidizing environments • Plain carbon steel • Gray cast iron • Tool steel • Stainless steel • Zinc • Brass • Tungsten • Titanium alloy • Aluminum • Platinum

Reserve Question 32: Beryllium copper alloys Which of the following elements, when alloyed with copper, results in an alloy that is precipitation hardenable? (a) Beryllium (b) Zinc (c) Gold (d) Tin (e) Lead

Reserve Questions and Problems • R-69 Reserve Question 33: Brass

Reserve Question 40: Noble metal advantages

Which of the following are primary constituents of brass? (a) Copper and zinc (c) Copper and lead (b) Copper and iron (d) Tin and zinc

Which of the following are desirable characteristics of the noble metals? (a) High strengths. (b) High ductilities. (c) Oxidation resistance. (d) High electrical conductivities.

Reserve Question 34: Bronze compositions Which four of the following elements are alloyed with copper to produce bronze alloys? (a) Zinc (d) Silicon (b) Tin (e) Nickel (c) Aluminum (f) Lead

Reserve Question 35: Cast alloys 01 Which type of nonferrous alloy is amenable to mechanical deformation? (a) Cast (b) Wrought

Reserve Question 41: Noble metals Which of the following are noble metals? (a) silver (g) iridium (b) gold (h) osmium (c) platinum (i) plutonium (d) palladium (j) zirconium (e) rhodium (k) lead (f) ruthenium

Reserve Question 42: Refractory alloys Reserve Question 36: Cast alloys 02 Which type of nonferrous alloy is not often amenable to mechanical deformation? (a) Cast (b) Wrought

Reserve Question 37: Magnesium alloys Which of the following is (are) desirable characteristics of magnesium and its alloys? (a) Very corrosion resistant in a variety of environments. (b) Low melting temperatures. (c) Easily work-hardened. (d) Very high specific strengths.

Reserve Question 38: Mg alloys replacing plastics For which of the following reasons have magnesium alloys replaced engineered plastics having comparable densities? (a) Magnesium alloys are stiffer. (b) Magnesium alloys are more recyclable. (c) Magnesium alloys are cheaper to produce.

Reserve Question 39: Nickel alloys In which of the following environments do nickel and its alloys perform extremely well? (a) Acidic (b) Basic

Which of the following are refractory metals? (a) niobium (e) copper (b) molybdenum (f) titanium (c) tungsten (g) iron (d) tantalum (h) aluminum

Reserve Question 43: Superalloys Which of the following are the primary superalloy metals? (a) Irons (d) Titanium (b) Nickel (e) Copper (c) Cobalt (f) Aluminum

Reserve Question 44: Titanium alloys Which of the following are desirable characteristics of titanium and its alloys? (a) Corrosion resistant. (b) Low melting temperatures. (c) Easily processed, even at high temperatures. (d) High strengths. (e) High ductilities.

Reserve Question 45: Zinc content of brass At room temperature, what is the approximate maximum zinc content of α-brass? (a) 5 wt% Zn (d) 35 wt% Zn (b) 15 wt% Zn (e) 45 wt% Zn (c) 25 wt% Zn

R-70 • Reserve Questions and Problems Reserve Problem 46a (question pool)

Reserve Problem 48a (question pool)

Select T/F for each of the following statements regarding aluminum/aluminum alloys: (a) Aluminum alloys are generally not viable as lightweight structural materials in humid environments because they are highly susceptible to corrosion by water vapor. (b) Aluminum alloys are generally superior to pure aluminum, in terms of yield strength, because their microstructures often contain precipitate phases that strain the lattice, thereby hardening the alloy relative to pure aluminum. (c) Aluminum is not very workable at high temperatures in air, in terms of extrusion and rolling, because a non-protective oxide grows and consumes the metal, converting it to a hard and brittle ceramic. (d) Compared to most other metals, like steel, pure aluminum is very resistant to creep deformation. (e) The relatively low melting point of aluminum is often considered a significant limitation for structural applications.

Select T/F for each of the following statements regarding copper & copper alloys: (a) Copper has a higher elastic modulus than aluminum. (b) The density of copper is closer to that of aluminum than it is to iron. (c) Bronze is an alloy of copper and zinc. (d) Copper and its alloys form a green tarnish over time, consisting of sulfides and carbonates. (e) Copper is relatively resistant to corrosion by neutral and even mildly basic water, making it useful for freshwater plumbing applications.

Reserve Problem 47a (question pool) Select T/F for each of the following statements regarding aluminum/aluminum alloys: (a) Aluminum alloys are generally viable as lightweight structural materials in humid environments because they are not very susceptible to corrosion by water vapor. (b) Aluminum is not very workable at high temperatures in air, in terms of extrusion and rolling, because a non-protective oxide grows and consumes the metal, converting it to a hard and brittle ceramic. (c) Aluminum alloys are generally superior to pure aluminum, in terms of yield strength, because their microstructures often contain precipitate phases that strain the lattice, thereby hardening the alloy relative to pure aluminum. (d) Compared to other metals, like steel, pure aluminum is very resistant to failure via fatigue. (e) Aluminum exhibits one of the highest melting points of all metals, which makes it difficult and expensive to cast.

Reserve Problem 49a (question pool) Select T/F for each of the following statements regarding copper & copper alloys: (a) Copper is much more abundant in the earth’s crust compared to iron or aluminum. (b) Copper is one of just a few metals that can be found in metallic form in nature. (c) Pure and/or annealed copper is more difficult to machine compared to its work-hardened form or its alloys. (d) Copper is a minor component (by weight) of most brass & bronze alloys. (e) Amongst metals and alloys copper is one of the best conductors of heat.

Reserve Problem 50a (question pool) Select T/F for each of the following statements regarding various metals & alloys: (a) Nickel is majority component (by mass) in certain superalloys such as WaspaloyTM. (b) Tungsten is the lowest density metal that has structural use. (c) Tantalum offers extremely good corrosion resistance, especially at low temperatures. (d) Magnesium metal is very similar to aluminum in terms of its physical and mechanical properties. (e) Beryllium metal is commonly used as an alloying agent in copper metal.

Reserve Questions and Problems • R-71 Reserve Question 51: Alumina content of fireclays

Reserve Problem 57

Increasing the alumina (Al2O3) content of fireclays results in (a) an increase in maximum service temperature. (b) a decrease in maximum service temperature.

Find the maximum temperature to which the following two magnesia–alumina refractory materials may be heated before a liquid phase will appear. (a) A spinel-bonded alumina material of composition 95 wt% Al2O3–5 wt% MgO. (b) A magnesia–alumina spinel of composition 65 wt% Al2O3–35 wt% MgO. Consult Figure 10.24.

Reserve Question 52: Alumina in silica refractories The high-temperature performance of silica refractories is compromised by the presence of even small concentrations of alumina (Al2O3). (a) True (b) False

Reserve Question 53: Porosity effects As the porosity of refractory ceramic bricks increases, (a) Strength decreases. (b) Strength increases. (c) Chemical resistance decreases. (d) Chemical resistance increases. (e) Thermal insulation decreases. (f) Thermal insulation increases.

Reserve Question 54: Silica in basic refractories The presence of silica (SiO2) in basic refractory ceramics is beneficial to their high-temperature performance. (a) True (b) False

Reserve Question 55: Slag application of basic refractories Basic refractory ceramics are often used for the containment of slags that are rich in (a) silica. (b) CaO. (c) MgO.

Reserve Question 56: Slag application of silica refractories Silica refractory ceramics are often used for the containment of slags that are rich in (a) silica. (b) CaO. (c) MgO.

Reserve Question 58: Abrasive materials Materials that are used as abrasive ceramics include which of the following? (a) Diamond (b) Silicon carbide (c) Tungsten carbide (d) Aluminum oxide (e) Silica sand (f) Titanium dioxide

Reserve Question 59: Abrasive properties Which of the following are properties required for abrasive ceramics? (a) High wear resistance (b) High temperature stability (c) Low temperature stability (d) High toughness (e) High ductility

Reserve Question 60: Cement consumption Which of the following cement materials is consumed in the largest tonnages? (a) Portland cement (b) Plaster of Paris (c) Lime

Reserve Question 61: Hardening mechanism of lime The hardening of lime is associated with (a) a drying process. (b) A chemical reaction involving water (i.e. hydration). (c) A chemical reaction involving compound other than water.

R-72 • Reserve Questions and Problems Reserve Question 62: Hardening mechanism of Portland cement The hardening of Portland cement is associated with (a) a drying process. (b) A chemical reaction involving water (i.e. hydration). (c) A chemical reaction involving a compound other than water.

Reserve Question 63: Fluorocarbons Which of these polymers are most resistant to attack by chemicals and, as such, are often used as coatings? (a) Fluorocarbons (c) Polyethylene (b) Polystyrene (d) Rubber

Reserve Question 64: Optical transparency For applications that require optical transparency, a polymer must be which of the following: (a) Amorphous. (b) Semicrystalline with very small crystallites. (c) Semicrystalline with very large crystallites. (d) Crystalline.

Reserve Question 65: Plastics Which of the following polymers are classified as plastics? (a) Polyethylene (b) Polypropylene (c) Poly(vinyl chloride) (d) Polystyrene (e) The epoxies (f) The polyesters (g) Rubber (h) Polyisoprene (i) Polychloroprene

Reserve Question 66: Crosslinking of elastomers Elastomers must have some crosslinking. (a) True (b) False

Reserve Question 67: Fiber molecular weight For fiber applications, the molecular weight of a polymer should be (a) Relatively high. (b) Relatively low.

CHAPTER 14 SYNTHESIS, FABRICATION, AND PROCESSING OF MATERIALS Reserve Question 01: Advantages of hot vs cold working Which type of forming operation produces a higher quality surface finish, better mechanical properties, and closer dimensional control of the finished piece? (a) Cold working (b) Hot working

Reserve Question 04: Forging

Reserve Question 02: Cold working

Hot working takes place at a temperature that is above a metal’s (a) melting temperature (b) recrystallization temperature (c) eutectoid temperature (d) glass transition temperature

Cold working takes place at a temperature that is below a metal’s (a) Melting temperature (b) Recrystallization temperature (c) Eutectoid temperature (d) Glass transition temperature

Reserve Question 03: Deformation in hot vs cold working Which type of forming operation has lower deformation energy requirements? (a) Cold working (b) Hot working

Forging operations normally take place at (a) Low temperature (b) Room temperature (c) High temperature

Reserve Question 05: Hot working

Reserve Question 06: Metal forming Which of the following are forming operations? (a) Forging (e) Powder metallurgy (b) Rolling (f) Welding (c) Extrusion (g) Continuous casting (d) Drawing (h) Die casting

Reserve Questions and Problems • R-73 Reserve Question 07: Annealing

Reserve Question 15: Normalizing cooling

Which of the following may occur during annealing? (a) Stresses may be relieved. (b) Ductility may be increased. (c) Toughness may be increased. (d) A specific microstructure may be produced.

A normalizing heat treatment is terminated by cooling in (a) Air (b) A furnace

Reserve Question 08: Annealing temperature How does increasing the annealing temperature influence the rate of an annealing process? (a) Increases the rate (b) Decreases the rate

Reserve Question 09: Full annealing Full annealing is used on which types of steels? (a) Low-carbon steels (b) Medium-carbon steels (c) High-carbon steels

Reserve Question 10: Full annealing temperature Full annealing is accomplished by heating at a temperature approximately how many degrees Celsius above either A3 line (for compositions less than the eutectoid) or A1 line (for compositions greater than the eutectoid) (a) 25°C (d) 55°C (b) 40°C (e) 70°C (c) 50°C

Reserve Question 16: Powder metallurgy The density of a piece produced by powder metallurgy may be the same as the parent material. (a) True (b) False

Reserve Question 17: Spheroidizing A spheroidizing heat treatment is normally used on which type(s) of steels? (a) Low-carbon steels (b) Medium-carbon steels (c) High-carbon steels

Reserve Problem 18 Give the approximate minimum temperature at which it is possible to austenitize each of the following iron–carbon alloys during a normalizing heat treatment: (a) 0.20 wt% C (b) 0.76 wt% C (c) 0.95 wt% C.

Reserve Question 11: Full annealing cooling

Reserve Problem 19

A full annealing heat treatment is terminated by cooling in (a) Air (b) A furnace

Give the approximate temperature at which it is desirable to heat each of the following iron–carbon alloys during a full anneal heat treatment: (a) 0.25 wt% C (b) 0.45 wt% C (c) 0.85 wt% C (d) 1.10 wt% C.

Reserve Question 12: Metals for powder metallurgy For which type of metals is powder metallurgy particularly suited? (a) Metals having high melting temperatures (b) Metals having low melting temperatures

Reserve Question 13: Normalizing Normalizing of a ferrous alloy causes the average grain size to (a) Increase (b) Decrease

Reserve Question 14: Normalizing temperature Normalizing is accomplished by heating at a temperature at least how many degrees Celsius above the upper critical temperature? (a) 25°C (d) 55°C (b) 40°C (e) 70°C (c) 50°C

Reserve Question 20: Cooling rate–Geometry I The smaller the ratio of surface are to the mass of steel specimen, (a) The slower the cooling rate, and consequently, the shallower the hardening effect (b) The slower the cooling rate, and consequently, the deeper the hardening effect (c) The faster the cooling rate, and consequently, the shallower the hardening effect (d) The faster the cooling rate, and consequently, the deeper the hardening effect

R-74 • Reserve Questions and Problems Reserve Question 21: Cooling rate– Geometry II Based upon a specimen’s surface area-to-mass ratio, which geometrical shape is more amenable to hardening by quenching? (a) Irregular with edges and corners (b) Regular and rounded

Reserve Question 22: Jominy end-quench test composition

Reserve Question 27: Quenching media Which of the following sequences correctly indicates the severity of quench order of the three quenching media, from least severe to most severe? (a) Water; oil; air (b) Water; air; oil (c) Oil; water; air (d) Air; oil; water (e) Air; water; oil

An alloy steel (containing Ni, Cr, Mo, etc.) may be hardened to a greater degree than an unalloyed steel.

This behavior is due to the presence of the alloying elements that delay austenite-to-pearlite and austeniteto-bainite reactions. (a) True (b) False

Reserve Question 28: Quenching media–steel

Reserve Question 23: Jominy end-quench test cooling rate

Reserve Question 29: Severity of quench

The rate of heat transfer from the specimen during a Jominy end-quench test is nearly independent of composition. (a) True (b) False

Reserve Question 24: Martensitic content vs strength I For parts that are to be used in relatively high stress applications, what percentage of the part’s interior should be martensite? (a) 40% (e) 80% (b) 50% (f) 90% (c) 60% (g) 100% (d) 70%

Reserve Question 25: Martensitic content vs strength II For parts that are to be used in moderately stressed applications, what percentage of the part’s interior should be martensite? (a) 40% (e) 80% (b) 50% (f) 90% (c) 60% (g) 100% (d) 70%

Reserve Question 26: Quenching During a quenching treatment, it is possible to cool the specimen at a uniform rate throughout the entire piece. (a) True (b) False

Which of the three quenching media is most commonly used for alloy steels? (a) Oil (b) Water (c) Air

The more “severe” a quench, (a) The more rapid the quench. (b) The less rapid the quench.

Reserve Question 30: Glass forming methods Match each product with the glass forming method that is used to produce it.

Dishes • Drawing • Blowing • Pressing • Fiber forming Light bulbs • Blowing • Pressing • Fiber forming • Drawing Rods • Pressing • Fiber forming • Drawing • Blowing Fibers • Blowing • Drawing • Fiber forming • Pressing

Reserve Questions and Problems • R-75 Reserve Question 31: Glass phases Which of the following represents the correct phase transformation sequence as a glass material is heated? (a) Solid; supercooled liquid; liquid (b) Solid; liquid; supercooled liquid (c) Supercooled liquid; solid; liquid (d) Supercooled liquid; liquid; solid (e) Liquid; supercooled liquid; solid (f) Liquid; solid; supercooled liquid

Reserve Question 32: Temperature points relative to glasses Match the viscosity values with the names of their corresponding temperature points.

100 Pa-s • Melting point • Working point • Softening point • Annealing point • Strain point 103 Pa-s • Softening point • Annealing point • Strain point • Working point • Melting point 4 × 106 Pa-s • Working point • Softening point • Annealing point • Strain point • Melting point 1012 Pa-s • Softening point • Melting point • Working point • Strain point • Annealing point 3 × 1013 Pa-s • Annealing point • Strain point • Working point • Melting point • Softening point

Reserve Question 33: Thermal stress reduction Once thermal stresses have been introduced into a ceramic piece, it is impossible to remove them. (a) True (b) False

Reserve Question 34: Thermal tempering The strength of a glass piece may be improved by inducing thermal compressive residual surface stresses. (a) True (b) False

Reserve Question 35: Thermal tempering stresses Thermal tempering results in the introduction of (a) compressive stresses on the surface (b) compressive stresses internally (c) tensile stresses on the surface (d) tensile stresses internally

Reserve Question 36: Thermal tempering temperature During thermal tempering, a glass piece is heated to a temperature (a) below the glass transition temperature (b) above the glass transition temperature (c) below the softening point (d) above the softening point

Reserve Question 37: Particle size of clay products The larger the initial particle size of a clay-based ceramic body that has been dried, (a) the lower the shrinkage (b) the greater the shrinkage

Reserve Question 38: Vitrification As the vitrification of clay-based products increases, which of the following also increase(s)? (a) Shrinkage (c) Durability (b) Strength (d) Density

Reserve Question 39: Water content of clay products During drying, the greater the initial water content of a clay-based ceramic body, (a) the greater the shrinkage (b) the lower the shrinkage

Reserve Question 40: Plastic deformation in powder pressing During the powder pressing of ceramic pieces, plastic deformation of the particles occurs. (a) True (b) False

R-76 • Reserve Questions and Problems Reserve Question 41: Powder pressing

Reserve Question 42: Powder pressing techniques

Which of the following ceramic products are normally produced using powder pressing? (a) Clay ceramics (b) Electronic ceramics (c) Magnetic ceramics (d) Refractory ceramics (e) Glass ceramics

If a ceramic piece is desired that is dense and, in addition, is to experience very little or no grain growth during its processing, which of the following powder pressing techniques should be used? (a) Uniaxial pressing, followed by firing. (b) Isostatic pressing, followed by firing. (c) Hot pressing.

CHAPTER 15 COMPOSTIES Reserve Question 01: Hardness matrix vs dispersed

Reserve Question 06: Critical fiber length

For composite materials, which is phase is normally harder? (a) The matrix phase (b) The dispersed phase

What is the order of magnitude critical length of glass and carbon fibers in composites? (a) 0.01 mm (d) 10.0 mm (b) 0.1 mm (e) 100 mm (c) 1.0 mm

Reserve Question 02: Particle content As particle content is increased, how does the strength a particle-reinforced composite change? (a) it increases (b) it decreases

Reserve Question 03: Cermets In order to produce very hard cermet (ceramic-metal) composites, what volume percent of the particulate phase is normally used? (a) > 50 vol% (b) > 60 vol% (c) > 70 vol% (d) > 80 vol% (e) > 90 vol%

Reserve Question 04: Dispersion-strengthened composite vs precipitation-hardened alloy II Which material retains its strength better at elevated temperatures? (a) A dispersion-strengthened composite (b) A precipitation-hardened alloy

Reserve Question 05: Continuous fibers The length of continuous fibers is typically (a) l > 5 lc (b) l > 15 lc (c) l > 25 lc (d) l > 35 lc (e) l > 45 lc

Reserve Problem 07a (question pool) Such that the bond strength across the fiber-epoxy interface is [s] MPa, and the shear yield strength of the epoxy is [y] MPa, compute the minimum fiber length, in millimeters, to guarantee that the fibers are conveying an optimum fraction of force that is applied to the composite. The tensile strength of these carbon fibers is [f] MPa.

Reserve Problem 08: Reinforcement efficiency I For an aligned fibrous composite, when a stress is applied in a direction that is parallel to the fibers, what is the reinforcement efficiency? (a) 0 (d) 3∕4 (b) 1∕5 (e) 1 3 (c) ∕8

Reserve Problem 09: Reinforcement efficiency II For an aligned fibrous composite, when a stress is applied perpendicular to the fibers, what is the reinforcement efficiency? (a) 0 (d) 3∕4 (b) 1∕5 (e) 1 3 (c) ∕8

Reserve Problem 10: Reinforcement efficiency III For a fibrous composite with fibers that are randomly and uniformly oriented within a specific plane, when a stress is applied in any direction within the plane of the fibers, what is the reinforcement efficiency? (a) 0 (d) 3∕4 1 (b) ∕5 (e) 1 (c) 3∕8

Reserve Questions and Problems • R-77 Reserve Problem 11: Reinforcement efficiency IV

Reserve Problem 18a (question pool)

For a fibrous composite with fibers that are uniformly distributed and randomly oriented in all directions, when a stress is applied in any direction, what is the reinforcement efficiency? (a) 0 (d) 3∕4 1 (b) ∕5 (e) 1 (c) 3∕8

The figure below depicts a continuous aligned fiberreinforced composite featuring carbon fiber and epoxy. If the elastic moduli of the composite components are [m] GPa and [f] GPa, what is the expected modulus, in GPa, for the depicted loading scenario if the fibers comprise [v] vol% of the composite?

Reserve Question 12: Applied load A stress-strain test is performed on an aligned fibrous composite such that the force is applied in the longitudinal direction. During the initial stage of the test, which phase bears most of the load? (a) Fibers (b) Matrix

Reserve Question 13: Composite failure Once the fibers fail in a fibrous composite, catastrophic failure of the piece takes place. (a) True (b) False

Reserve Question 14: Continuous fiber orientation

Reserve Problem 19a (question pool)

How are continuous fibers typically oriented in fibrous composites? (a) Aligned (b) Partially oriented (c) Randomly oriented

The figure below depicts the elastic modulus rulesof-mixtures for an aligned and continuous fiber-reinforced epoxy composite. What is the composite modulus, measured parallel to the fiber alignment axis, for a sample containing 80 vol% fiber? Note that the volume fraction axis is intentionally unlabeled. You should be able to discern this vol% label for yourself based on the logic for producing a structural composite.

Reserve Question 15: Discontinuous fiber orientation How are discontinuous fibers typically oriented in fibrous composites? (a) Aligned (b) Partially oriented (c) Randomly oriented

Reserve Question 16: Discontinuous vs continuous fiber use If the fiber orientation is random, which type of fibers is normally used? (a) Discontinuous (b) Continuous

Reserve Problem 17a (question pool) Select T/F for each of the following statements: (a) Composites are single-phase materials by definition. (b) The term “composite” applies to materials that feature polymeric materials only. (c) Structural composites are, in general, highly regarded for their specific strengths. (d) Composites featuring continuous and aligned fibers for reinforcement generally offer properties that are highly isotropic compared to most metals (random polycrystals).

(a) 5 GPa (b) 7.5 GPa (c) 10 GPa (d) 15 GPa

(e) 20 GPa (f) 25 GPa (g) 30 GPa

R-78 • Reserve Questions and Problems Reserve Problem 20a (question pool)

Reserve Question 22: Fiber types

The figure below depicts the elastic modulus rulesof-mixtures for an aligned and continuous fiberreinforced epoxy composite. What is the composite modulus, measured parallel to the fiber alignment axis, for a sample containing 80 vol% fiber? Note that the volume fraction axis is intentionally unlabeled.

You should be able to discern this vol% label for yourself based on the logic for producing a structural composite.

Match each fiber type with its description.

Whiskers • Polycrystalline or amorphous materials with small diameters • Single crystals with extremely large length-todiameter ratios • Metals having relatively large diameters Fibers • Single crystals with extremely large length-todiameter ratios • Metals having relatively large diameters • Polycrystalline or amorphous materials with small diameters Wires • Metals having relatively large diameters • Polycrystalline or amorphous materials with small diameters • Single crystals with extremely large length-todiameter ratios

Reserve Question 23: Fiber properties

(a) 5 GPa (b) 7.5 GPa (c) 10 GPa (d) 15 GPa (e) 20 GPa (f) 25 GPa (g) 30 GPa

For a composite material, which phase normally has the higher elastic modulus? (a) Fiber phase (b) Matrix phase

Reserve Question 24: Matrix properties For a composite material, how does the ductility of the matrix phase normally compare with the ductility of the dispersed phase? (a) more ductile (b) less ductile

Reserve Question 21: Fiber materials Which of the following materials are typically used as fibers? (a) Graphite/carbon (b) Silicon carbide (c) Silicon nitride (d) Aluminum oxide (e) Glass (f) Boron (g) Steel (h) Tungsten (i) Molybdenum

Reserve Question 25: Aramid fiber composites Aramid fiber-reinforced composites have very high tensile strengths and relatively low compressive strengths. (a) True (b) False

Reserve Questions and Problems • R-79 Reserve Question 26: Aramid fibers Which of aramid and metal fibers have higher strengthto-weight ratios? (a) Aramid fibers (b) Metal fibers

Reserve Question 27: Carbon fiber composites Carbon fiber-reinforced composites have which of the following properties? (a) Relatively high strengths (b) Relatively high stiffnesses (c) High service temperatures (>200°C)

Reserve Question 28: Whisker materials Which of the following materials are typically used as whiskers? (a) graphite/carbon (b) silicon carbide (c) silicon nitride (d) aluminum oxide (e) glass (f) boron (g) steel (h) tungsten (i) molybdenum

Reserve Question 29: Wire materials Which of the following materials are typically used as wires in composites? (a) graphite/carbon (b) silicon carbide (c) silicon nitride (d) aluminum oxide (e) glass (f) boron (g) steel (h) tungsten (i) molybdenum

Reserve Question 30: Ceramic-matrix composites Compared to other ceramic materials, ceramic-matrix composites have better/higher (a) fracture toughnesses (b) oxidation resistance (c) stability at elevated temperatures

Reserve Question 31: Transformation-toughened composites Which of the following materials are typically used as stabilizers in transformation-toughened ceramicmatrix composites? (a) CaO (b) MgO (c) Y2O3 (d) CeO (e) Al2O3 (f) SiC

Reserve Question 32: Carbon-carbon composites Carbon-carbon composites exhibit which of the following properties/characteristics? (a) High tensile moduli at elevated temperatures (b) High tensile strengths at elevated temperatures (c) Resistance to creep (d) Large fracture toughness values (e) High thermal conductivities (f) Low coefficients of thermal expansion (g) Resistance to oxidation at elevated temperatures (h) Low cost

Reserve Question 33: Laminar composites Laminar composites have high strengths in all directions (in three dimensions). (a) True (b) False

R-80 • Reserve Questions and Problems Reserve Problem 34a (question pool)

Reserve Problem 35a (question pool)

The figure below depicts four equal-sized composite plates created by laminating separate sheets of unidirectional Kevlar reinforced polyester. Which of the following laminate configurations would exhibit the lowest strain if elastically loaded with an axial force F, as depicted below? Select (e) if the strains for each of the laminate configurations are equivalent.

The figure below depicts four equal-sized composite plates created by laminating separate sheets of unidirectional Kevlar reinforced polyester. Which of the following laminate configurations is expected to exhibit the most anisotropic mechanical properties?

Select (e) if the laminate configurations exhibit an equivalent degree of anisotropy.

(a)

(a)

(b) (b)

(c)

(c)

(d)

(d)

Reserve Question 36: Sandwich panels The strong outer sheets of sandwich panels are separated by a layer of material that is (a) less dense than the outer sheet material (b) more dense than the outer sheet material

Reserve Questions and Problems • R-81

CHAPTER 16 CORROSION AND DEGRADATION OF MATERIALS Reserve Problem 01: Electrochemical cell temperature An electrochemical cell is constructed such that on one side a pure lead electrode is in contact with a solution containing Pb2+ ions at a concentration of 0.002 M. The other cell half consists of a pure nickel electrode that is immersed in a solution of Ni2+ ions having a concentration of 0.5 M. Given that the standard electrode potentials for lead and nickel are −0.126 and −0.250 V, respectively, at what temperature will the potential between the two electrodes be −0.017 V?

Reserve Question 02: Chemical attack resistance

Reserve Question 05: Galvanic series I Metals near the top of the galvanic series are (a) Cathodic (c) Unreactive (b) Anodic (d) Reactive

Reserve Question 06: Galvanic series II Metals near the bottom of the galvanic series are (a) Cathodic (c) Unreactive (b) Anodic (d) Reactive

Reserve Question 07: Metal oxidation/ reduction

Which material type is more resistant to attack by acidic and alkaline solutions? (a) Polymeric materials (b) Metallic materials

Metal ions in solution may only be oxidized. (a) True (b) False

Reserve Question 03: EMF–least reactive

In a corrosion process, only one reduction reaction is possible. (a) True (b) False

Below are shown, for five metals, reduction reactions and standard electrode potential values. Which of these metals is the least reactive?

Electrode reaction

Standard electrode potential (V )

Au3+ + 3 e− → Au

+1.420

−

+ 2 e → Cu

+0.340

Ni2+ + 2 e− → Ni

−0.250

2+ + 2 e− → Fe

−0.440

Cu Fe

2+

Na+ + e− → Na

(a) Au (b) Cu (c) Ni

−2.924

(d) Fe (e) Na

Reserve Question 04: EMF–most reactive Below are shown, for five metals, reduction reactions and standard electrode potential values. Which of these metals is the most reactive?

Electrode reaction

Standard electrode potential (V )

Au3+ + 3 e− → Au

+1.420

Cu2+ + 2 e− → Cu

Reserve Question 08: Multiple reduction reactions

Reserve Question 09: Overall electrochemical reaction An overall electrochemical reaction must consist of at least (a) A single reduction reaction (b) A single oxidation reaction (c) A single reduction reaction and a single oxidation reaction

Reserve Question 10: Oxidation I Oxidation of an atom involves the (a) Loss of electrons (b) Gain of electrons

Reserve Question 11: Oxidation II Oxidation takes place at the (a) Anode (b) Cathode

+0.340

Reserve Question 12: Oxidation III

2+

−

+ 2 e → Ni

−0.250

2+

−

−0.440

Which of the following is/are oxidation reactions? (a) Fe → Fe2+ + 2 e− (b) Al → Al3+ + 3 e− (c) 2 H+ + 2 e− → H2 (d) H2 → 2 H+ + 2 e−

Ni

Fe

+

+ 2 e → Fe −

Na + e → Na

(a) Au (b) Cu (c) Ni

−2.924

(d) Fe (e) Na

R-82 • Reserve Questions and Problems Reserve Question 13: Oxidation of metals

Reserve Question 20: Environmental effects

Most metals and alloys are subject to oxidation. (a) True (b) False

Which of the following factors may influence the corrosion rates of materials? (a) Fluid velocity (b) Temperature (c) Fluid composition

Reserve Question 14: Reduction I Reduction of an atom involves the (a) loss of electrons (b) gain of electrons

Reserve Question 15: Reduction II Reduction takes place at the (a) anode (b) cathode

Reserve Question 16: Reduction III Which of the following are reduction reactions? (a) Fe → Fe2+ + 2 e− (c) 2 H+ + 2 e− → H2 (b) Al → Al3+ + 3 e− (d) H2 → 2 H+ + 2 e−

Reserve Question 17: Activation and concentration polarizations I Match the polarization conditions with their descriptions Reaction rate is controlled by the slowest step in the electrochemical reaction.

• Activation polarization • Concentration polarization Reaction rate is controlled by the diffusion of ions in solution.

• Activation polarization • Concentration polarization

Reserve Question 18: Passivity–maintenance Once a metal has become passivated, it will always remain so. (a) True (b) False

Reserve Question 19: Passivity–metals Alloys of which of the following metals may passivate? (a) Chromium (b) Iron (c) Nickel (d) Titanium (e) Copper (f) Gold

Reserve Question 21: Forms of corrosion–crevice corrosion Which of the following describes crevice corrosion? (a) Oxidation and reduction reactions occur randomly over the surface. (b) Two metals/alloys of different compositions are coupled while exposed to an electrolyte. (c) Corrosion that results from a difference in concentration of ions or dissolved gases in the electrolyte. (d) Localized corrosion that may be initiated at the surface defect. (e) Corrosion that occurs preferentially along grain boundaries. (f) One element is preferentially removed as a result of corrosion. (g) Corrosion resulting from the combined action of chemical attach and mechanical abrasion or wear. (h) Corrosion resulting from the combined action of an applied tensile stress and a corrosive environment.

Reserve Question 22: Forms of corrosion–erosion corrosion Which of the following describes erosion corrosion? (a) Oxidation and reduction reactions occur randomly over the surface. (b) Two metals/alloys of different compositions are coupled while exposed to an electrolyte. (c) Corrosion that results from a difference in concentration of ions or dissolved gases in the electrolyte. (d) Localized corrosion that may be initiated at the surface defect. (e) Corrosion that occurs preferentially along grain boundaries. (f) One element is preferentially removed as a result of corrosion. (g) Corrosion resulting from the combined action of chemical attach and mechanical abrasion or wear. (h) Corrosion resulting from the combined action of an applied tensile stress and a corrosive environment.

Reserve Questions and Problems • R-83 Reserve Question 23: Forms of corrosion– galvanic corrosion

Reserve Question 25: Forms of corrosion– pitting

Which of the following describes galvanic corrosion? (a) Oxidation and reduction reactions occur randomly over the surface. (b) Two metals/alloys of different compositions are coupled while exposed to an electrolyte. (c) Corrosion that results from a difference in concentration of ions or dissolved gases in the electrolyte. (d) Localized corrosion that may be initiated at the surface defect. (e) Corrosion that occurs preferentially along grain boundaries. (f) One element is preferentially removed as a result of corrosion. (g) Corrosion resulting from the combined action of chemical attach and mechanical abrasion or wear. (h) Corrosion resulting from the combined action of an applied tensile stress and a corrosive environment.

Which of the following describes pitting? (a) Oxidation and reduction reactions occur randomly over the surface. (b) Two metals/alloys of different compositions are coupled while exposed to an electrolyte. (c) Corrosion that results from a difference in concentration of ions or dissolved gases in the electrolyte. (d) Localized corrosion that may be initiated at the surface defect. (e) Corrosion that occurs preferentially along grain boundaries. (f) One element is preferentially removed as a result of corrosion. (g) Corrosion resulting from the combined action of chemical attach and mechanical abrasion or wear. (h) Corrosion resulting from the combined action of an applied tensile stress and a corrosive environment.

Reserve Question 24: Forms of corrosion– intergranular corrosion Which of the following describes intergranular corrosion? (a) Oxidation and reduction reactions occur randomly over the surface. (b) Two metals/alloys of different compositions are coupled while exposed to an electrolyte. (c) Corrosion that results from a difference in concentration of ions or dissolved gases in the electrolyte. (d) Localized corrosion that may be initiated at the surface defect. (e) Corrosion that occurs preferentially along grain boundaries. (f) One element is preferentially removed as a result of corrosion. (g) Corrosion resulting from the combined action of chemical attach and mechanical abrasion or wear. (h) Corrosion resulting from the combined action of an applied tensile stress and a corrosive environment.

Reserve Question 26: Forms of corrosion–selective leaching Which of the following describes selective leaching? (a) Oxidation and reduction reactions occur randomly over the surface. (b) Two metals/alloys of different compositions are coupled while exposed to an electrolyte. (c) Corrosion that results from a difference in concentration of ions or dissolved gases in the electrolyte. (d) Localized corrosion that may be initiated at the surface defect. (e) Corrosion that occurs preferentially along grain boundaries. (f) One element is preferentially removed as a result of corrosion. (g) Corrosion resulting from the combined action of chemical attach and mechanical abrasion or wear. (h) Corrosion resulting from the combined action of an applied tensile stress and a corrosive environment.

R-84 • Reserve Questions and Problems Reserve Question 27: Forms of corrosion–stress corrosion

Reserve Question 30: Corrosion prevention– cathodic protection

Which of the following describes stress corrosion? (a) Oxidation and reduction reactions occur randomly over the surface. (b) Two metals/alloys of different compositions are coupled while exposed to an electrolyte. (c) Corrosion that results from a difference in concentration of ions or dissolved gases in the electrolyte. (d) Localized corrosion that may be initiated at the surface defect. (e) Corrosion that occurs preferentially along grain boundaries. (f) One element is preferentially removed as a result of corrosion. (g) Corrosion resulting from the combined action of chemical attach and mechanical abrasion or wear. (h) Corrosion resulting from the combined action of an applied tensile stress and a corrosive environment.

Cathodic protection reduces the corrosion rate of a metal when an electrical connection is made to another metal that is (a) lower in the galvanic series (b) higher in the galvanic series

Reserve Question 28: Forms of corrosion–uniform corrosion Which of the following describes uniform corrosion? (a) Oxidation and reduction reactions occur randomly over the surface. (b) Two metals/alloys of different compositions are coupled while exposed to an electrolyte. (c) Corrosion that results from a difference in concentration of ions or dissolved gases in the electrolyte. (d) Localized corrosion that may be initiated at the surface defect. (e) Corrosion that occurs preferentially along grain boundaries. (f) One element is preferentially removed as a result of corrosion. (g) Corrosion resulting from the combined action of chemical attach and mechanical abrasion or wear. (h) Corrosion resulting from the combined action of an applied tensile stress and a corrosive environment.

Reserve Question 29: Fresh vs seawater Which water environment is more corrosive? (a) Fresh water (b) Seawater

Reserve Question 31: Corrosion prevention– temperature In most instances, one way to reduce the corrosion rate is to (a) Increase the fluid temperature. (b) Decrease the fluid temperature.

Reserve Question 32: Galvanizing Galvanizing involves applying a layer of what metal to the surface of steel? (a) zinc (b) iron (c) copper (d) nickel (e) aluminum

Reserve Question 33: Pilling–Bedworth ratio I Given the following metal–Pilling-Bedworth ratio combinations, which metals are expected to form protective coatings?

Metal Aluminum Chromium Copper Lithium Molybdenum Silicon Sodium

(a) aluminum (b) chromium (c) copper (d) lithium (e) molybdenum (f) silicon (g) sodium

P-B Ratio 1.28 1.99 1.68 0.57 3.40 2.27 0.57

Reserve Questions and Problems • R-85 Reserve Question 34: Pilling—Bedworth ratio II

Reserve Question 35: Polymer degradation

Given the following metal–Pilling-Bedworth ratio combinations, which metals are not expected to form protective coatings?

Polymer degradation may occur from exposure to or as a result of which of the following? (a) Electrochemical reactions (b) Physiochemical reactions (c) Swelling (d) Heat (e) Radiation

Metal Aluminum Chromium Copper Lithium Molybdenum Silicon Sodium

P-B Ratio 1.28 1.99 1.68 0.57 3.40 2.27 0.57

(a) aluminum (b) chromium (c) copper (d) lithium (e) molybdenum (f) silicon (g) sodium

Reserve Question 36: Swelling The swelling of a polymer results in it becoming (a) Softer (b) Harder

Reserve Question 37: Swelling reduction Polymer deterioration by swelling may be reduced by (a) Increasing the degree of crosslinking (b) Decreasing the degree of crosslinking (c) Increasing the molecular weight (d) Decreasing the molecular weight (e) Increasing the degree of crystallinity (f) Decreasing the degree of crystallinity

CHAPTER 17 THERMAL PROPERTIES Reserve Question 01: Constant pressure vs constant volume heat capacity

Reserve Question 05: Material thermal expansion

For a given material, which heat capacity is greater? (a) At constant pressure, Cp . (b) At constant volume, Cv .

Which of the following material types typically has the largest values of the coefficient of thermal expansion? (a) Polymers (b) Metals (c) Ceramics

Reserve Question 02: Debye temperature I Below the Debye temperature, Cv is virtually independent of temperature. (a) True (b) False

Reserve Question 03: Debye temperature II For most solid materials, the Debye temperature is below room temperature. (a) True (b) False

Reserve Question 04: Electron contributions In which of the following thermal phenomena do free electrons play a role? (a) Thermal conductivity (b) Thermal expansion

Reserve Question 06: Thermal expansion and atomic bonding energy The greater the atomic bonding energy, (a) The larger the interatomic spacing change with increasing temperature. (b) The smaller the interatomic spacing change with increasing temperature. (c) The larger the value of αl. (d) The smaller the value of αl.

Reserve Question 07: Thermal expansion anisotropy When heated, most materials expand equally in all directions. (a) True (b) False

R-86 • Reserve Questions and Problems Reserve Problem 08

Reserve Question 13: Thermal shock resistance

The difference between the specific heats at constant pressure and volume is described by the expression

Which of the following properties lead to a high degree of thermal shock resistance? (a) High fracture strength (b) Low fracture strength (c) High thermal conductivity (d) Low thermal conductivity (e) High modulus of elasticity (f) Low modulus of elasticity (g) High coefficient of thermal expansion (h) Low coefficient of thermal expansion

Cp − Cv =

α2v v0 T β

where αv is the volume coefficient of thermal expansion, v0 is the specific volume (i.e. volume per unit mass, or the reciprocal of density), β is the compressibility, and T is the absolute temperature.

Compute the values of Cv, at room temperature (293 K) for copper and nickel using the data in Table 17.1, assuming that αv = 3αl and given that the values for β for Cu and Ni are 8.35 × 10−12 and 5.51 × 10−12(Pa)−1, respectively.

Reserve Question 09: Material thermal conductivity Which of the following material types typically has the largest values of the thermal conductivity? (a) Polymers (b) Metals (c) Ceramics

Reserve Question 10: Thermal conductivity of ceramics In the vicinity of room temperature, how do the thermal conductivities of ceramics change as the temperature increases? (a) they decrease (b) they increase

Reserve Question 11: Thermal conductivity of polycrystalline vs single crystal How do thermal conductivities of single crystals and polycrystalline materials compare? (a) ksingle crystal > kpolycrystalline (b) ksingle crystal < kpolycrystalline

Reserve Question 12: Thermal shock in brittle materials Which of rapid heating or rapid cooling is more likely to inflict thermal shock in brittle materials? (a) Rapid cooling (b) Rapid heating

Reserve Question 14: Thermal stress The heating of a homogeneous and isotropic rod of solid material for which axial motion is restrained, results in which type of thermal stresses? (a) Compressive (b) Tensile

Reserve Problem 15 (a) If a rod of 1025 steel 0.5 m (19.7 in.) long is heated from 20°C to 80°C (68°F to 176°F) while its ends are maintained rigid, determine the type and magnitude of stress that develops.

Assume that at 20°C the rod is stress-free. (b) What will be the stress magnitude if a rod 1 m (39.4 in.) long is used? (c) If the rod in part (a) is cooled from 20°C to −10°C (68°F to 14°F), what type and magnitude of stress will result?

Reserve Problem 16 To what temperature would 23.0 kg of some material at 100°C be raised if 255 kJ of heat is supplied?

Assume a cp value of 423 J/kg-K for this material. (a) 26.2°C (c) 126°C (b) 73.8°C (d) 152°C

Reserve Problem 17 A rod of some material 0.50 m long elongates 0.40 mm on heating from 50°C to 151°C. What is the value of the linear coefficient of thermal expansion for this material? (a) 5.30 × 10–6 (°C)–1 (c) 1.60 × 10–5 (°C)–1 (b) 7.92 × 10–6 (°C)–1 (d) 1.24 × 10–6 (°C)–1

Reserve Questions and Problems • R-87 Reserve Problem 18

Reserve Problem 20a (question pool)

Which of the following sets of properties leads to a high degree of thermal shock resistance? (a) High fracture strength High thermal conductivity High modulus of elasticity High coefficient of thermal expansion (b) Low fracture strength Low thermal conductivity Low modulus of elasticity Low coefficient of thermal expansion (c) High fracture strength High thermal conductivity Low modulus of elasticity Low coefficient of thermal expansion (d) Low fracture strength Low thermal conductivity High modulus of elasticity High coefficient of thermal expansion

Which of the following 1 kg samples is expected to change temperature the least if 100 kJ of heat is perfectly transferred to each of them at a constant pressure of 1 atmosphere. The initial temperature of each specimen is 25oC. (a) Aluminum (b) Copper (c) Gold (d) Borosilicate Glass (e) Polystyrene

Reserve Problem 19a (question pool)

Reserve Problem 22

A 10 meter long square bar of 316 stainless steel (edge length of 5 cm, with a modulus of 193 GPa and a yield point of 290 MPa) was bolted securely in place when its installation temperature was around [I]oC. What is the expected thermal stress in the bar when its service temperature reaches [F]oC? Enter a negative indicate compressive stress, if necessary. The thermal expansion coefficient of 316 stainless steel is 16.0 × 10−6 1/oC.

This ceramic outlier has the highest room-temperature thermal conductivity of about 2,000 watts per meter per kelvin, a value that is five time higher than the best thermally conductive metals. (d) SrTiO3 (a) Al2O3 (b) CaF2 (e) C (diamond) (c) TiO2

Reserve Problem 21a (question pool) If you were to locally heat identical geometry plates of the materials listed below with the same heat source, which would increase in temperature the fastest? (a) Polystyrene (b) Aluminum (c) Copper (d) Gold (e) Borosilicate Glass

CHAPTER 18 MAGNETIC PROPERTIES Reserve Question 01: Ferromagnetics

Reserve Question 02: Antiferromagnetics

Which two of the following are ferromagnetic materials? (a) Aluminum oxide

Which of the following materials display(s) antiferromagnetic behavior? (a) Aluminum oxide (b) Copper (c) Aluminum (d) Titanium (e) Iron (α ferrite) (f) Nickel (g) MnO (h) Fe3O4 (i) NiFe204

(b) Copper (c) Aluminum (d) Titanium (e) Iron (α ferrite) (f) Nickel (g) MnO (h) Fe3O4 (i) NiFe204

R-88 • Reserve Questions and Problems Reserve Question 03: Ferrimagnetics

Reserve Question 07: Domains and crystals

Which of the following are ferrimagnetic materials? (a) Aluminum oxide (b) Copper (c) Aluminum (d) Titanium (e) Iron (α ferrite) (f) Nickel (g) MnO (h) Fe3O4 (i) NiFe204

In a polycrystalline material, each grain will always consist of just a single domain. (a) True (b) False

Reserve Problem 04 The formula for yttrium iron garnet (Y3Fe5O12) may c be written in the form Y3Fea2Fed3 O12 , where the superscripts a, c, and d represent different sites on which the Y3+ and Fe3+ ions are located. The spin magnetic moments for the Y3+ and Fe3+ ions positioned in the a and c sites are oriented parallel to one another and antiparallel to the Fe3+ ions in d sites. Compute the number of Bohr magnetons associated with each Y3+ ion, given the following information: (1) each unit cell consists of eight formula (Y3Fe5O12) units; (2) the unit cell is cubic with an edge length of 1.2376 nm; (3) the saturation magnetization for this material is 1.0 × 104 A/m; and (4) assume that there are 5 Bohr magnetons associated with each Fe3+ ion.

Reserve Question 05: Curie temperature At the Curie temperature, the saturation magnetization abruptly diminishes. Which of the following magnetic material types will have Curie temperatures? (a) Diamagnetics (b) Paramagnetics (c) Ferromagnetics (d) Antiferromagnetics (e) Ferrimagnetics

Reserve Question 06: Neel temperature With increasing temperature antiferromagnetic materials eventually become which of the following? (a) Diamagnetics (b) Paramagnetics (c) Ferromagnetics (d) Antiferromagnetics (e) Ferrimagnetics

Reserve Problem 08 A coil of wire 0.1 m long and having 15 turns carries a current of 1.0 A. (a) Compute the flux density if the coil is within a vacuum. (b) A bar of an iron–silicon alloy, the B-H behavior for which is shown in Figure 18.29, is positioned within the coil. What is the flux density within this bar? (c) Suppose that a bar of molybdenum is now situated within the coil. What current must be used to produce the same B field in the Mo as was produced in the iron–silicon alloy part (b) using 1.0 A?

Reserve Problem 09 The following data are for a transformer steel: H (A/m) 0 10 20 50 100 150

B (tesla) 0 0.03 0.07 0.23 0.70 0.92

H (A/m) 200 400 600 800 1000

B (tesla) 1.04 1.28 1.36 1.39 1.41

(a) What are the values of the initial permeability and initial relative permeability? (b) What is the value of the maximum permeability? (c) At about what H field does this maximum permeability occur? (d) To what magnetic susceptibility does this maximum permeability correspond?

Reserve Problem 10 Estimate saturation values of H for single-crystal iron in [100], [110], and [111] directions.

Reserve Questions and Problems • R-89 Reserve Question 11: Hard/soft materials

Reserve Question 13: Hard magnetic materials

Which type(s) of magnetic materials may be classified as either soft or hard? (a) Diamagnetic (d) Antiferromagnetic (b) Paramagnetic (e) Ferrimagnetic (c) Ferromagnetic

Which of the following characteristics are displayed by hard magnetic materials? (a) A relatively small hysteresis loop.

Reserve Question 12: Soft magnetic materials Which of the following characteristics are displayed by soft magnetic materials? (a) A relatively small hysteresis loop. (b) A relatively large hysteresis loop. (c) Magnetization and demagnetization may be achieved using relatively low applied fields. (d) Magnetization and demagnetization require relatively high applied fields.

(b) A relatively large hysteresis loop. (c) Magnetization and demagnetization may be achieved using relatively low applied fields. (d) Magnetization and demagnetization require relatively high applied fields.

Reserve Problem 14 Using Equation 18.14, determine which of the superconducting elements in Table 20.7 are superconducting at 3 K and in a magnetic field of 15,000 A/m.

CHAPTER 19 OPTICAL PROPERTIES Reserve Problem 01: Wavelength calculations

Reserve Question 05: Light transmission

What are (a) the frequency and (b) the energy (in eV) of a photon of light having a wavelength of 8.8 × 10−7 m? The value for Planck’s constant is 4.13 × 10−15 eV-s. Express your answer to part (a) in scientific notation.

Match the type of light transmission with its description.

Reserve Question 02: Visible wavelength What is the order of magnitude wavelength for visible light? (a) 0.5 Angstroms (b) 0.5 nanometers (c) 0.5 micrometers (d) 0.5 millimeters (e) 0.5 meters (f) 0.5 kilometers

Reserve Question 03: Bulk metal light transmission In the visible spectrum, a thick metal specimen will be (a) Transparent (b) Translucent (c) Opaque

Reserve Question 04: Insulator light transmission In the visible spectrum, an electrical insulator that is a single crystal and without porosity is normally (a) Transparent (b) Opaque (c) Translucent

Transmits light with relative little absorption.

• Translucent • Transparent • Opaque Transmits light diffusely.

• Opaque • Translucent • Transparent Is impervious to light transmission.

• Transparent • Opaque • Translucent

Reserve Question 06: Semiconductor light transmission In the visible spectrum, a semiconductor that is a single crystal and nonporous may be (a) Transparent (b) Translucent (c) Opaque

Reserve Question 07: EM radiation and metals To which of the following electromagnetic radiation types are bulk metals opaque? (a) radio waves (d) ultraviolet radiation (b) microwaves (e) X-rays (c) infrared radiation

R-90 • Reserve Questions and Problems Reserve Question 08: Nonmetallic opaqueness

Reserve Problem 12a (question pool)

Every nonmetallic material becomes opaque to electromagnetic radiation having some wavelength. (a) True (b) False

A collimated beam containing two different frequencies of light travels through vacuum and is incident on a piece of glass. Which of the schematics below depicts the phenomenon of dispersion within the glass in a qualitatively correct manner? Select (e) if none of the options are qualitatively correct.

Reserve Question 09: Ceramics and light transmission

(a)

Match the following material types with their light transmission characteristics.

Single crystal electrical insulators • Opaque • Translucent • Transparent Polycrystalline and nonporous electrical insulators • Translucent • Transparent • Opaque

(b)

Porous electrical insulators • Transparent • Opaque • Translucent (c)

Reserve Question 10: Index of refraction For noncubic crystals, the index of refraction is lowest in the crystallographic direction that has the (a) Highest atomic packing density (b) Lowest atomic packing density

Reserve Question 11: Polymer crystallinity and light transmission A completely amorphous and nonporous polymer will be (a) Transparent (b) Translucent (c) Opaque

(d)

Reserve Questions and Problems • R-91 Reserve Problem 13a (question pool) A beam of light is shined on a thin (sub-millimeter thick) single crystal wafer of material. The light source is special since it can be tuned to provide any wavelength of visible light on demand. The specimen is illuminated such that the frequency of light is decreased over time while the transmitted intensity of the light is measured. If the sample becomes transparent when the frequency is less than [F] THz, what is the band gap of the material, in eV? Assume that an intrinsic excitation of electrons is responsible for the absorption.

Reserve Problem 14 Select the word combination that best completes this statement.

When a semiconductor is exposed to a light source, its intrinsic carrier concentration will increase if the [a] of the light is [b] than band gap of the semiconductor. [a] intensity, energy, wavelength, frequency, voltage, current, resistance [b] greater, less

Reserve Question 15: Fluorescence and phosphorescence Match the luminescence characteristics with their descriptions.

Reemission of photons occurs in much less than one second after excitation.

• Phosphorescence • Fluorescence Reemission of photons occurs in more than one second after excitation.

• Fluorescence • Phosphorescence

Reserve Question 16: Luminescent materials Only pure materials luminesce. (a) True (b) False

CHAPTER 20 ECONOMIC, ENVIRONMENTAL, AND SOCIETAL ISSUES IN MATERIALS SCIENCE AND ENGINEERING There are no Reserve Questions and Problems for this chapter.