8/28/2011
Padding y Chaplet: Chaplets are used to support cores inside the
y Tapering of thinner section towards thicker section
is known as 'padding'.
mould cavity. y Chill: Chills are metallic objects, which are placed in
the the h mould ld to increase i h cooling li rate off castings. i
y This will require extra material.
g is not p g or y If p padding provided, centre line shrinkage porosity will result in the thinner section.
y Riser: It is a reservoir of molten metal provided in the
casting so that hot metal can flow back into the mould cavity when there is a reduction in volume of metal due to solidification Compiled by: S K Mondal Made Easy
Contd…
Compiled by: S K Mondal Made Easy
IES‐2001
IES‐1996 Which of the following methods are used for
The main purpose of chaplets is
obtaining directional solidification for riser design
(a) To ensure directional solidification
1.
Suitable placement of chills
(b) To provide efficient venting
2.
Suitable placement of chaplets
3.
Employing padding
(c) For aligning the mold boxes
Select the correct answer.
(d) To support the cores Ans. (d)
(a) 1 and 2 (b) 1 and 3
(c) 2 and 3
(d) 1, 2 and 3
Ans. (b) Compiled by: S K Mondal Made Easy
IES 2007 Which one of the following is the correct statement? Gate is provided in moulds to (a) Feed the casting at a constant rate (b) Give passage to gases (c) Compensate for shrinkage (d) Avoid cavities Ans. (a) Compiled by: S K Mondal Made Easy
Compiled by: S K Mondal Made Easy
GATE‐2009 Match the items in Column I and Column II. Column I Column II P. Metallic Chills 1. Support for the core Q. Metallic Chaplets 2. Reservoir of the molten metal R. Riser 3. Control cooling of critical sections S. Exothermic Padding 4. Progressive solidification (a) P‐1,Q‐3, R‐2, S‐4 (b) P‐1,Q‐4, R‐2, S‐3 (c) P‐3, Q‐4, R‐2, S‐1 (d) P‐4, Q‐1, R‐2, S‐3 Ans. (d) Compiled by: S K Mondal Made Easy
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