Effect of Ambient Temperature on Impact Compressive Strength of Gum Metal
Hidetoshi KOBAYASHI, Keitaro HORIKAWA and Makoto KISHI
Abstract:Recently, a kind of titanium alloy which has outstanding properties, such as low elastic modulus, high strength, super elasticity and super plasticity has been developed by TOYOTA Central R&D, Inc. and named “gum metal”. Because of a new alloy, the mechanical properties of gum metal has not been clarified enough. In this paper, therefore, impact compression tests on gum metal were carried out at a nominal strain rate of about 1200 s-1 and at various ambient temperatures (T =77K`773K) . For comparison, quasi-static compression tests were also performed at 6.7~10-4s-1. The flow stress σ at a strain of ε = 0.05 increased with an decrease in ambient temperature, especially σ ≈ 2050MPa at T =77K. In static tests, work hardening could be observed in a plastic region. In dynamic tests, however, work softening could be seen. It may be considered that adiabatic heating is one of the largest reasons. Key Words:Gum metal, Impact, Compression, Hopkinson bars, Various testing temperatures