Hot Deformation Behavior and Processing Map of Al-Zn-Mg-Cu-Zr Alloy

The hot deformation behavior of Al-Zn-Mg-Cu-Zr alloy was studied through isothermal compression experiment. During hot deformation, the temperature variation is ranging from 300 to 450 degrees C, and the strain rate is from 0.01 to 10 s-1. The Zener Hollomon model was applied to describe the flow behavior of Al-Zn-Mg-Cu-Zr alloy during high-temperature plastic deformation. The high accuracy of the constitutive equation has been verified through the establishment of a 6th order polynomial. i.e., the values of correlation coefficient and verage relative error enable to reach 0.9736 and 5.925%, respectively. Moreover, based on the construction of processing map for the aluminum alloy, the optimal temperature and strain rate ranges were determined to be 300-360 degrees C and 0.01-0.1 s-1, respectively. A large amount of recrystallized grains are generated at low strain rate region due to the sufficient time for dynamic recrystallization, in which situation is relatively suitable for processing of workpiece. In addition, more precipitates were formed at 450 degrees C and 0.1 s-1.