Research on High-Precision Thermoplastic Phenomenological Constitutive Models of TC4 Titanium Alloy

To accurately predict the thermoforming process of TC4 titanium alloy, the high-temperature rheological behavior of TC4 titanium alloy was investigated, and a high-precision thermoforming phenomenological constitutive model was developed. Firstly, high-temperature tensile tests of TC4 titanium alloy were conducted at 973-1123 K with strain rates of 0.01-1 s-1. Based on the experimental data, two constitutive models were established: an Arrhenius constitutive model with strain compensation and a modified Johnson-Cook constitutive model. Sparrow search algorithm (SSA) was employed to optimize the model parameters. Finally, the predictive abilities of the phenomenological constitutive models for TC4 titanium alloy were assessed using statistical analysis. The results indicate that the Arrhenius constitutive model achieves relatively high predictive accuracy despite limited experimental data. However, it has a restricted parameter optimization space. In contrast, the modified Johnson-Cook constitutive with lower predictive accuracy, offers a larger parameter optimization space. The SSA-optimized modified Johnson-Cook constitutive model provides a good fit with experimental results, serving as a solid foundation for high-precision numerical simulations of TC4 titanium alloy thermoforming.