Hot Deformation Behavior and Elastic-viscoplastic Constitutive Model of As-Cast Titanium Alloy

In this work, the hot compression experiments of as-cast Ti-6554 alloy are carried out with the temperature range of 950-1 150 ℃ and the strain rate range of 0.001-10 s^-1. An elastic-viscoplastic constitutive model to describe the hot deformation of titanium alloy is established based on the theory of finite deformation and flow curve. The hot deformation behaviors of titanium alloy in the flow curve such as flow softening, steady flow, work hardening, discontinuous yield and adiabatic temperature rise are captured using a one-dimensional linear regression Arrhenius equation with strain corrected. In addition, the finite element subroutine of the constitutive model is developed to simulate the hot compression process of samples at different strain rates and temperatures. The experimental results are in good agreement with the predicted ones, proving that the established constitutive model can accurately capture the complex flow characteristics of titanium alloy during hot deformation.