Chapter 10 Torsion Tests
Chapter 10 Torsion Tests
Chapter 10 Torsion Tests
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Hot torsion testing<br />
• Under hot-working condition<br />
(T > 0.6T m , εεεε up to <strong>10</strong> 3 s -1 ), torsion test<br />
is often used to obtain data on the flow<br />
properties and fracture.<br />
Cold-working<br />
condition<br />
Warm-working<br />
condition<br />
Hot-working<br />
condition<br />
Torque-twist curves at different<br />
temperatures for a nickel-based alloy<br />
www.kompas.or.kr<br />
Hot torsion testing machine<br />
• In hot working condition (m>>n),<br />
the maximum shear stress is<br />
expressed as follows;<br />
M T τ a ( 3 + m + n)<br />
3<br />
Eq.<strong>10</strong><br />
=<br />
2πa<br />
Where<br />
m is strain rate sensitivity<br />
n is the strain hardening exponent.<br />
in torsion at εεεε =2.5 s<br />
Suranaree University of Technology May-Aug 2007<br />
-1 .<br />
Tapany Udomphol
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