Materials at High Temperatures 30(2),2013:145-150

Dynamic behaviour of Ti-17 alloy under high strain rates at elevated temperatures
Baolin Wang, Xing Ai, Zhanqiang Liu* and Jun Zhao

ABSTRACT: The dynamic mechanical behaviour of Ti-17 alloy deformedat high strain rates ranging from 6,000 to 12,000 s-1 and temperatures between 473K and 1,073K isstudied using the Split Hopkinson Pressure Bar. The stress–strain curves ofmaterial under temperature–strain rate coupling actions are obtained. The mechanismof effect of temperature and strain rate on the plastic flow stress of Ti-17alloy is discussed. The results show that the Ti-17 alloy has an evident heatsoftening effect, strain rate strengthening effect and strain hardening effect,and flow stress decreases with the temperature increase. But under different strainrates at a given temperature, the flow stress shows an obvious work softeningphenomenon, this is a result of a competition between thermal softening andwork hardening when the dynamic softening effect is sufficient to counteractthe work-hardening effect under high strain rates.

Keywords: high strain rate, high temperature deformation, dynamicmechanical behaviour, Ti-17 alloy

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