Investigation on hot deformation behavior of AZ31 magnesium alloy

The hot compressive deformation of extruded AZ31magnesium alloy with the mass fractions of Al and Zn equal to 3 % and 1 % respectively is studied by a Gleeble-1500D thermal mechanical simulator over the temperature range from 200 ℃ to 400 ℃ and the strain rate from 10-3 s-1 to 100 s-1. The true stress-strain curves of the strain of 65 % are tested. The deformation activation energy is obtained and the flow stress model is established by analyzing the effects of strain rate and temperature on the flow stress. Zener-Hollomon parameter is introduced to describe the softening behaviors of AZ31 magnesium alloy resulted from dynamic recrystallization during the hot compressive deformation, whose natural logarithm is linear with the critical strain of dynamic recrystallization.