Hot Compressive Deformation Behavior and Constitutive Equation of Al-9.39Zn-1.92Mg-1.98Cu Alloy

Hot compression tests for the Al-9.39Zn-1.92Mg-1.98Cu alloy were carried out at the temperature ranging from 300 degrees C to 460 degrees C and the strain rate ranging from 0.001 s(-1) to 1 s(-1), and the height reduction degree was 70%. The flow stress was corrected because of the effect of friction. Results show the flow stress decreases with increasing the temperature or decreasing the strain rate. The friction effect becomes more and more obvious with increasing the temperature and decreasing the strain rate. A revised constitutive equation considering the influence of strain is established based on the Arrhenius-type model. Comparing the experimental and predicted flow stresses, the revised constitutive equation has higher accuracy. Their correlation coefficient and average absolute relative error is 0.996 and 2.45%, respectively.