The flow behavior and constitutive equations in isothermal compression of 7050 aluminum alloy

The flow behavior of 7050 aluminum alloy was investigated by means of isothermal compression tests. Isothermal compression of 7050 aluminum alloy was carried out on a Gleeble-1500 thermal simulation machine at the deformation temperatures ranging from 593K to 743K, the strain rates ranging from 0.01s^-1 to 20.0s^-1, and the height reductions of 30%, 50% and 70%. The characteristics of stress-strain curves are determined by the interaction of work hardening, dynamic recovery and dynamic recrystallization. The flow stress decreases with the increasing of deformation temperature and the decreasing of strain rate. The relationship between microstructure and processing parameters was analyzed. The constitutive equations for characterizing the flow behavior during the whole deformation process had been established, based on the experimental results and the kinetic analysis. The average relative error between the calculated and the experimental flow stress is 5.73%, which indicates that the constitutive equations can be used to predict the flow behavior of 7050 aluminum alloy accurately during high temperature deformation.