Effects of Deformation Rate on the Mechanical Properties of an Industrial Al-Zn-Mg-Cu Alloy

Abstract

The deformation parameters of aluminum alloys during thermal deformation have a significant impact on the alloy's properties. The industrial free forging of the Al-Zn-Mg-Cu alloy was carried out at deformation rates of 10 mm/s and 20 mm/s, respectively, at a deformation temperature of 430°C and a deformation degree of 60% in this study. The microstructure was determined using EBSD, and the mechanical characteristics were examined. According to EBSD observations, the recrystallization fraction of the alloy is nearly identical under both deformation rates; however, the average grain size of the alloy with a deformation rate of 10 mm/s is 10.8 μm larger than that of the alloy with a deformation rate of 20 mm/s. As the deformation rate increased from 10 mm/s to 20 mm/s, the alloy's yield strength and fracture toughness increased. The resistance to fatigue crack propagation, on the other hand, displayed the reverse pattern. That is, the alloy with a 20 mm/s deformation rate had a higher FCP rate than the alloy with a 10 mm/s deformation rate. In summary, the influence of deformation rate on the microstructure and mechanical properties of a high alloy Al-Zn-Mg-Cu alloy was investigated.