High Temperature Deformation Mechanism of 7075 Aluminum Alloy

摘要

This paper presents the high temperature deformation behavior of 7075 aluminum alloy after T6 heat treatment by using electron tensile test machine with a temperature range of 230 - 440 ℃, strain rate of 0.01 s~(-1), deformation of 50 % and 100 %, respectively. The morphology of the fractured surfaces, dislocation and change of sub-grains before and after the tensile test were investigated by using scanning electron microscope (SEM) and electron back scattering diffraction (EBSD) technique. The results show that the fracture mechanism of 7075 aluminum alloy was ductile rupture. The thermal deformation of the 7075 aluminum alloy showed the steady-state flow characteristics, and the flow stress decreased with the increase of deformation temperature. Orientation angle offset of the grain boundary decreased with the increasing of the deformation at 440 ℃, indicating that the continuous dynamic recrystallization occurred inside the 7075 aluminum alloy.