Constitutive Model of Dynamic Softening Behavior of 7075 Aluminum Alloy during Hot Compression

Hot compression tests of 7075 aluminum alloy were performed on Gleeble-1500 thermal simulater at strain rate of 0.01-10 s-1and deformation temperature of 250-450℃.The true stress-true strain curves during the deformation process were obtained.The constitutive model of the alloy during deformation at high temperatures was obtained through fitting regression and the strain behavior was predicted.The results show that the simulation results of the Fields-Backofen constitutive model agreed well with the test values before the peak value of the flow stress,while the predicted values of the model which contained a softening factor were closer to the test values.