Constitutive Model of TC4-DT Titanium Alloy at Elevated Temperature Considering Compensation of Strain

Abstract:

Elevated-temperature flow behavior of TC4-DT titanium alloy was investigated by conducting isothermal hot compression tests at strain rate from 0.01 to 10 s-1 and in the temperature range of 1181~1341 K on Gleeble-3500 simulator. The Arrhenius constitutive equation considering the strain was established based on the experiment data with the material constants expressed by a polynomial fitting of strain. The results show that all the true stress-strain curves exhibit the characteristics of strain hardening followed by flow softening and it is particularly significant at higher strain rates and lower temperatures. The flow stress values predicted by the developed constitutive model demonstrate a well agreement with the experimental results at the strain rates under 1 s-1. The correlation coefficient (R) and average absolute relative error (AARE) are 0.9952 and 5.78%, respectively, which con?rm that the modi?ed constitutive equation could give an accurate and precise estimate of the ?ow stress of TC4-DT titanium alloy.

Key words:TC4-DT titanium alloy; elevated-temperature deformation; strain compensation; constitutive model