Asymmetry in the hot deformation behavior of AZ31B magnesium sheets

The in-plane tension and compression tests of AZ31B magnesium sheets were carried out at the temperature range of 473-573 K and the strain rate range of 0.001-0.1 s−1. The experimental results show that the mechanical response transforms from asymmetry to symmetry when the temperature is above 573 K. Furthermore, the mechanical response under tension is rate-dependent, but that under compression can be decomposed to two parts of rate-dependent and rate-independent. The flow stress models under tension and compression were proposed to quantitatively describe the deformation behavior of AZ31B magnesium, respectively. Moreover, the microstructure and texture evolution were investigated. The results show that although the asymmetry of mechanical response does not exist at 573 K, the microstructure evolutions during tension or compression are still different, which implies that the mechanism and preferred orientation of dynamic recrystallization (DRX) grains in different deformation directions are different.