A physically-based constitutive modelling of a high strength aluminum alloy at hot working conditions

The hot deformation behavior of a high strength aluminum alloy (Al-Zn-Mg-Cu) was studied by isothermal hot compression tests performed over a range of temperatures (350-490 °C) and strain rates (0.001-1 s−1). A constitutive equation was established using experimental results to predict the flow stress of the alloy under elevated temperature. In the work hardening-dynamic recovery regime, a physically-based constitutive equation for the flow stress was obtained from the stress-dislocation relation. In the subsequent dynamic recrystallization region, the flow stress after the peak was predicted by employing the kinematics of the dynamic recrystallization in the constitutive model. The stress-strain curves of the alloy predicted by the established models were in good agreement with experimental results. The results indicate that the proposed physically-based constitutive equation can accurately predict the flow behavior of the Al-Zn-Mg-Cu alloy.