On the mechanical behavior of cold deformed aluminum 7075 alloy at elevated temperatures

In the present study, elevated temperature deformation behavior and microstructural evolution of 7075 aluminum alloy at annealed and cold rolled conditions were examined. Isothermal uniaxial tensile tests at a temperature range of 200-350 °C and at a strain rate range of 0.001-0.1 s−1 were conducted to investigate the effects of deformation parameters on the mechanical behavior. High temperature flow was noticeably strain rate sensitive especially for the rolled condition. Cold work was shown to have a remarkable influence on increasing the peak stress up to 250 °C. At and above this temperature the rolled microstructure enabled higher ductility reaching over 50% accompanied by a stress plateau. The ductility drop at 350 °C at the slowest deformation rate was attributed to impurity rich regions with possible formation of secondary phases due to dynamic precipitation.