Constitutive modeling for the hot deformation behavior of Mg-3.06Zn-0.58Zr-1.07Y alloy

In order to improve the understanding flow behaviors of hot compressive deformation as-homogenized of Mg-3.06Zn-0.58Zr-1.07Y alloy, carried out a series of isothermal compressive tests with 60% height reduction of specimens were performed at constant temperature of 523 K, 573 K, 623 K, 673 K, and 723 K, and strain rates of 0.001, 0.01, 0.1, and 1 s(-1) on Gleeble-1500 thermo-mechanical simulator. The results of the true stress-strain curves show that the flow stress increases with the increasing strain rate and decreasing deformation temperature. The flow behavior at constant strain rate was characterized by the dynamic recrystallization and dynamic recovery softening mechanisms occur simultaneously. The number of the dynamic recrystallization curve increases with increasing strain rate. A nonlinear flow model and its constitutive equation, based on the Arrhenius-type equation, were employed for studying the deformation behavior and relationships between the deformation temperature, strain rate, and flow stress. Finally, the processing map of Mg-3.06Zn-0.58Zr-1.07Y alloy at the strain of 0.3 was obtained through the dynamic materials modeling. The optimal processing temperature and strain rate, using the microstructure and constitutive modeling, were found to be in the rage 623-723 K and 0.1-1 s(-1), respectively.