METALS

01 DuraSync side-acting grips for curved specimens

02 AutoX biax extensometer testing sheet metal for “r” and “n”

03 AutoX automatic extensometer for rebar testing

04 Clip on transverse extensometer

Grips and Fixtures

Wedge grips are the most commonly used grip type for metals testing. These can vary in how they perform. The industrial series DX/HDX testing systems can feature manual or hydraulic wedge grips built into the crosshead. Alternatively, manual, pneumatic, and hydraulic wedge grips are available in a range of capacities up to 2000 kN.

For some applications it may be beneficial to use hydraulic side acting grips. Instron® DuraSync™ grips provide reliable clamping with repeatable alignment with a patented mechanical linkage that protects the grips from damage experienced from side load due to bent, bowed or curved specimens.

Thin wires and foils can often be successfully tested using 2712 Series pneumatic and 2710 screw action tensile grips with smooth faces. Special grips are available for braided wires including 2714-010 wire tire cord grips, 2715 Series wire capstan grips, single and double side-acting grips with wire strand inserts and the SG series of wire and cable snubbing grips. For threaded or buttonhead specimens, 2717 Series, W-5158/W5159 shoulder end holders and W-5102 threaded end holders can be used.

Fatigue tests on metals can be performed using a variety of pre-loaded mechanical and hydraulic grips:

• 2742-301 30 kN hydraulic wedge grips are ideal for fatigue tests on smaller specimens as well as for r&n tests on sheet metals.

• 2742 and 2743 Series mechanical and hydraulic wedge grips provide full reverse-loading capability with a wide range of jaw face types and sizes including carbide-coated.

Fracture mechanics tests on CT specimens are readily performed with 2750 Series clevis grips. 2810 Series bend fixtures are ideal for fracture mechanics testing on bend specimens.

01 AutoX automatic extensometer for rebar testing

02 AutoX biax extensometer testing sheet metal for “r” and “n”

03 Split furnace and side entry extensometer to perform non-ambient testing

04 Long travel clip-on extensometer for rebar testing

Extensometry

Strain measurement is critical when testing metals, as the compliance of the load string will influence the extension measured from the crosshead movement. There are varying gauge lengths required for different standards, and different elongations required depending on the material type. Instron® T1M, T3M and 2630 Series clip-on extensometers are ideal for metals testing, providing accurate and stable strain data.

2663 AVE video extensometers provide a non-contacting solution for static metals testing, including the ablilty to measure transverse strain for plastic strain ratio (r-value) determination.

Automatic contacting extensometers such as the 2665-750 AutoX750 provide fully automatic strain measurement as well as direct control of strain rate in accordance with ISO 6892-1 Method A1 on suitable systems. Repeatability, productivity, flexibility and ease of use are also improved compared to traditional clip-on devices. 2665-751 AutoXBiaxial extensometers can also provide the ability to measure transverse strain for plastic strain ratio (r-value) determination.

Fatigue tests require extensometers with excellent dynamic performance. 2620 Series clip-on extensometers are light and compact and have high resonant frequencies, making them the best choice for fatigue tests including those run in strain control. 2670 Series crack-opening displacement (COD) gauges are suited for fracture mechanics tests and are available in a range of travels, gauge lengths and temperature ranges.

Environmental

Elevated temperature testing of metals can be accomplished using Instron’s furnace systems with associated pull rods and high temperature extensometry.

Software

Software for metals testing includes Bluehill® Universal for static tests. Dynamic tests on metals can be performed using WaveMatrix™ general purpose fatigue testing software as well as fracture mechanics packages aimed at fracture toughness, crack growth and J-integral applications.