Microstructure Evolution and Dynamic Recrystallization Model of Extruded AZ41M Magnesium Alloy During Hot Deformation

The hot deformation behavior of extruded AZ41M magnesium alloy at strain rate of 0.005–1 s−1 and temperature of 300–450 °C was studied through thermal simulation compression test. The microstructure evolution of the alloy during hot deformation was analyzed with metallographic microscope. The results show that with the decrease in temperature and the increase in strain rate, the peak stress of extruded AZ41M magnesium alloy increases significantly, which shows high sensitivity to temperature and strain rate. There is a typical unimodal dynamic recrystallization in the hot deformation process, which is mainly carried out in the form of discontinuous dynamic recrystallization. According to the experimental results, based on the work hardening rate–flow stress curve, the hot deformation dynamic recrystallization model of extruded AZ41M magnesium alloy is established by linear regression fitting, which includes critical strain equation, peak strain equation, kinetic equation and grain size equation.