Flow Stress Constitutive Equation of AZ31 Magnesium Alloy for Hot Compression

Abstract

The AZ31 magnesium alloy flow stresses have been investigated in the strain rates of 0.03~3s-1and temperature range of 300~400°C. The result showed that dynamic recovery and dynamic recrystallization occurred obviously during the hot compression of AZ31 magnesium alloy. In order to represent the flow stress of plastic deformation accurately, the constitutive equation was built by using the dynamic recovery model and dynamic recrystallization model, and its parameters of the constitutive equation were determined by multivariate nonlinear regression analysis. The two-step constitutive equation not only expressed the variation of flow stress with strain rate, deformation temperature and strain, but also revealed the characteristic of dynamic recrystallization kinetics of AZ31 magnesium alloy. Its accuracy was higher than the flow stress of hyperbolic sine model, and the maximum relative errors of two constitutive equation models calculation values compared with experiment data were 5% and 6.5% respectively.

The Analysis of Temperature and Strain Rate Influence on Flow Stress of Mg Alloy AZ31

“…3. The experiment has confirmed that flow stress is declining by increasing temperature and the formability of Mg alloy AZ31B is rising [6,7]. Advanced Engineering and Technology recommended temperature interval.…”