Deformation Behavior and Processing Map of High Temperature of TC21 Titanium Alloy

The compression test on TC21 titanium alloy was carried out in the temperature range of 860 similar to 940 degrees C and the strain rate range of 0.01 similar to 10s(-1) on Gleeble-1500D hot simulation machine. And the hot deformation behavior was studied. The processing map was calculated and analyzed according the dynamic materials model. It is found that the flow stress of TC21 decreases with the increasing of the temperature and the decreasing of the strain rate. The flow stress curves are characterized by steady state at low strain rate((epsilon)over dot <= 1 s(-1)) but discontinuous yield at high strain rate((epsilon)over dot >1 s(-1)). The processing map established at the true strain of 0.4 shows that there are three regions, instability and safe and peak region, and the efficiencies of power dissipation are 0 similar to 25%, 31%similar to 37% and 43%similar to 49% respectively. The peak region is the optimum hot working zone of TC21 titanium alloy.