Dynamic Recrystallization Behavior of TA15 Titanium Alloy under Isothermal Compression during Hot Deformation

Abstract

In order to improve the understanding of the dynamic recrystallization (DRX) behaviors of TA15 titanium alloy (Ti-6Al-2Zr-1Mo-1V), a series of experiments were conducted on a TMTS thermal simulator at temperatures of 1173 K, 1203 K, 1223 K, and 1273 K with the strain rates of 0.005 s−1, 0.05 s−1, 0.5 s−1, and 1 s−1. By the regression analysis for conventional hyperbolic sine equation, the activation energy of DRX in α+β two-phase region is QS=588.7 Kg/mol and in β region is QD=225.8 Kg/mol, and a dimensionless parameter controlling the stored energy was determined as Z/A=ε˙exp(588.7×103)/RT/6.69×1026 in α+β two-phase region and as Z/A=ε˙exp(225.8×103)/RT/5.13×1011 in β region. The DRX behaviors of TA15 titanium alloy were proposed on the strength of the experiment results. Finally, the theoretical prediction results of DRX volume fraction were shown to be in agreement with experimental observations.