A physical-based constitutive relation to predict flow stress for Cu-0.4Mg alloy during hot working

The hot deformation behaviors of Cu-0.4Mg alloy are studied by the isothermal compression tests on a Gleeble-1500 thermo-mechanical simulator over wide ranges of temperatures and strain rates. Based on the experimental results, a physical-based constitutive model is developed to predict the flow stress of Cu-0.4Mg alloy under elevated temperature. Results show that under a given strain rate, the flow stress will decrease with increasing temperature, while under a given temperature the flow stress will increase with increasing strain rate. The true stress-strain curves of Cu-0.4Mg alloy demonstrate the typical characteristics of dynamic recovery and dynamic recrystallization. The correlation coefficient (R) and the average absolute relative error (AARE) between the measured and predicted flow stresses are 0.99747 and 3.3846%, respectively. It indicates that the proposed physical-based constitutive model can accurately characterize the hot deformation behaviors including work-hardening, dynamic recovery and dynamic recrystallization for Cu-0.4Mg alloy.