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

• Tension responses of TC11 are investigated over a wide range of strain rates.
• Tension behavior of TC11 shows a positive strain-rate dependence.
• Transition of rate sensitivity is observed at moderate strain rates.

The effect of strain rate on the tension stress–strain responses of the Ti–6.6Al–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.