Comparative Study on Two Constitutive Models for Predicting Elevated-temperature Flow Behavior of TC4 Titanium Alloy

In order to establish a constitutive model to accurately predict the elevated-temperature flow behaviour of titanium alloy TC4, the hot compression test was carried out at the temperature of 500 ℃-900 ℃ and the strain rate of 0.01 s^-1-1 s^-1 with the Gleeble-3800 thermal simulator. Based on the experimental data, two constitutive models of modified Z-A and modified J-C were established. The predictability of the two constitutive models was compared and analyzed by the correlation coefficient R, average absolute relative error ARRE and relative error RE. The results show that the modified J-C constitutive model can accurately predict the flow behavior of TC4 titanium alloy under the above deformation conditions, and the correlation coefficient R, average absolute relative error ARRE and relative error RE of the model are 0.9997, 1.4536% and 0.0457, respectively. The research results provide a reference for the initial design of numerical models to predict the elevated-temperature flow behaviour of titanium alloy TC4, and are of great significance for the numerical simulation and parameter optimization of its hot forming process.