Constitutive model for elevated temperature flow stress of AZ41M magnesium alloy considering the compensation of strain

Abstract

The hot deformation behaviors of AZ41M magnesium alloy were studied via hot compression tests on a Gleeble-1500D thermal-mechanical simulation machine under the strain rate of 0.005–1 s−1 and deformation temperature of 573–723 K. According to the experimental results, the flow stress curves show a quintessential flow behavior with dynamic recrystallization softening as the strain increases. And with the decrease of strain rate or the increase of temperature, the flow stress decreases significantly. The effects of strain rate and deformation temperature on hot deformation behavior of AZ41M magnesium alloy were described by the Zener-Hollomon parameter in the exponent-type equation. Furthermore, the effect of strain was incorporated in the constitutive equations by considering all the material constants as different functions of strain. Consequently, the constitutive model of the studied AZ41M magnesium alloy taking the compensation of strain into consideration was proposed. The strain-dependent constitutive model correlates well with the experimental results, thereby confirming that the revised model can provide a precise and accurate prediction for the flow stress of AZ41M magnesium alloy.