Tension behavior of Ti-6.6Al-3.3Mo-1.8Zr-0.29Si alloy over a wide range of strain rates

The effect of strain rate on the tension stress strain responses of the Ti-6.6A1-3.3Mo-1.8Zr-0.29Si alloy are investigated at strain rates ranging from 0.001 to 940 s(-1). The values of tension yield strength increase with increasing strain rate. There exists the transition of rate sensitivity for flow stress under moderate-rate loading conditions. Moreover, strain rate has greater influence on the initial yielding than the strain hardening behavior. SEM observation shows that the alloy is broken in a manner of ductile fracture and the dimple size decreases with the increase of strain rate. A phenomenologically-based constitutive model is proposed to describe the rate-dependent tension behavior. The model correlations are in good agreement with the experimental data within the tested strain-rate range. (C) 2014 Elsevier B.V. All rights reserved.