A modified constitutive model and hot compression instability behavior of Cu-Ag alloy
(College of Material Science and Engineering, Chongqing University, Chongqing 400030, China)
Abstract: The hot compressive deformation behaviors of Cu-6wt.%Ag alloy were studied experimentally in the temperature range of 973-1123 K and the strain rate range of 0.01-10 s-1. The stress increases and reaches the maximum value when the true strain is very small, and then the stress changes slowly and tends to be stable under the action of work hardening, dynamic recovery and recrystallization. The material parameters of the conventional Arrhenius constitutive model are only related to strain under different deformation conditions, and the prediction error is large, which cannot accurately characterize the hot deformation behavior of the alloy. To describe the hot deformation behavior of the alloy accurately, a modified constitutive model was established by considering the simultaneous influence of forming temperature, strain rate and strain. The results indicate that correlation coefficient (R) and the average absolute relative error (AARE) are 0.993 and 4.2%, respectively. The modified constitutive model can accurately describe the hot deformation behavior of Cu-6wt.%Ag alloy.
Key words: Cu-Ag alloy; intragranular recrystallization; crack; modified Arrhenius model