Constitutive Model Prediction and Flow Behavior Considering Strain Response in the Thermal Processing for the TA15 Titanium Alloy

To investigate the flow stress, microstructure, and usability of TA15 titanium alloy, isothermal compression was tested at 1073-1223 K and strain rates of 10, 1, 0.1, 0.01, and 0.001 s(-1), and strain of 0.9. The impact of strain and temperature on thermal deformation was investigated through the exponent-type Zener-Hollomon equation. Based on the influence of various material constants (including , n, Q, and lnA) on the TA15 titanium alloy, the strain effect was included in the constitutive equation considering strain compensation, which is presented in this paper. The validity of the proposed constitutive equation was verified through the correlation coefficient (R) and the average absolute relative error (AARE), the values of which were 0.9929% and 6.85%, respectively. Research results demonstrated that the strain-based constitutive equation realizes consistency between the calculated flow stress and the measured stress of TA15 titanium alloy at high temperatures.