Hot deformation behavior of high Zn-containing 7A65 Al alloy

Hot deformation behavior and microstructural evolution of as-homogenized 7A65 Al alloy under isothermal compression at temperatures of 573–713 K and strain rates of 0.1–10.0 s⁻¹ were investigated. It was found that the flow stress of 7A65 Al alloy exhibited a typical dynamic recovery characteristic at high-temperature deformation conditions, and a sixth-order polynomial strain compensated Arrhenius constitutive equation was proposed to describe the flow behavior. Based on the dynamic material model and the Prasad standard, the hot processing map was established. The optimal processing conditions were within the temperature range of 633–713 K and the strain rate range of 0.1–0.5 s⁻¹ when the true strain exceeded 0.6. Deformation temperature and strain rate had an obvious effect on the microstructure evolution of 7A65 Al alloy, and the deformed microstructures were mainly composed of deformed grains and recovery structure. The main softening mechanism was dynamic recovery at the temperature of 573–713 K and the strain rate of 0.1–10.0 s⁻¹, but dynamic recrystallization was enhanced with the increase in temperature. Graphic abstract: [Figure not available: see fulltext.].