Hot compression deformation behavior and processing maps of Al–0.5Mg–0.4Si–0.1Cu alloy

Abstract

To improve the hot working stability of Al–0.5Mg–0.4Si–0.1Cu alloy, isothermal compression tests were performed at the temperature range of 350–500 °C and strain rate of 0.001–10 s−1. Strain-compensated Arrhenius constitutive equation containing Zener–Hollomon parameters was established to describe the hot deformation behavior. Its accuracy was evaluated within the whole strain range and the established constitutive equation can well predict the flow behavior. In addition, intrinsic machinability was further analyzed by constructing processing maps under different true strains based on dynamic material models. Microstructures are in fine agreement with processing maps and flow instability occurred mainly in high strain rate regions due to the presence of adiabatic shear bands and flow localization. Dynamic softening mechanism of the alloy mainly stems from dynamic recovery and partial dynamic recrystallization. Based on processing maps and microstructure observations, optimal process parameters of alloy were obtained, which are beneficial to optimize its hot working parameters.