Influence of Thermal Deformation Parameters on Mechanical Properties and Microstructure Evolution of AA7075 Aluminum Alloy during Hot Stamping-Quenching Process.

Hot tensile tests have been performed on AA7075 aluminum alloy to investigate the effects of temperature and strain rate on its deformation behavior during the hot stamping-quenching process. The corresponding mechanical properties and associated microstructures have also been studied. The results indicate that the flow behavior curves exhibit work hardening, a dynamic equilibrium, then a dramatic decrease, ultimately leading to fracture. Ductility of over 30% can be obtained at relatively low deformation temperature and strain rate. The fracture mechanism changes from ductile transgranular fracture to ductile intergranular fracture owing to the weakening of the grain-boundary strength at high temperatures. The strength of the tested samples after artificial aging treatment increases with the deformation temperature after solid-solution heat treatment. It is more appropriate to choose a temperature of 400°C and a strain rate of 0.1–1 s⁻¹ for AA7075 aluminum alloy parts to simultaneously obtain the desired ductility and final strength in this process. [ABSTRACT FROM AUTHOR]