Effect of Deformation Heating on the Flow Behavior and Processing Maps of Al–Zn–Mg–Cu Alloy

Abstract

The effects of deformation heating on hot deformation and processing maps of AA7050 aluminum alloy were investigated by hot compression tests at temperatures ranging from 300°C to 450°C with strain rates ranging from 0.001 s⁻¹ to 10 s⁻¹. The results show that deformation heating results in a decrease in flow stress and an increase in deformation resistance. The processing maps and microstructures exhibit that deformation heating may be responsible for flow instability. Compared to the processing maps of AA7050 aluminum alloy with deformation heating, the optimum hot-working area without deformation heating is smaller, which is determined to be at temperatures of 420–450°C and strain rates of 0.001–0.03 s⁻¹. The main deformation mechanisms are dynamic recrystallization (DRX) and dynamic recovery (DRV).

Fig. 5 Effect of deformation heating on the 3D diagram of power dissipation efficiency and instability diagram of AA7050 aluminum alloy: (a), (c) with deformation heating, (b), (d) without deformation heating.