Study on the deformation behavior of AZ31B-O magnesium alloy with the VPSC model

Abstract

The mechanical anisotropy of the magnesium alloy AZ31B-O was investigated using the Viscoplastic-Self-Consistent (VPSC)-Twinning and Detwinning (TDT) model. The anisotropic behavior of the material under uniaxial strain was studied using five distinct sheet orientations. In order to investigate the mechanical behavior under uniaxial compression, four alternative specimen orientations were employed. The VPSC model with the TDT mechanism was used to simulate the uniaxial tension and compression experiments. For tensile strain, the magnesium alloy samples were mainly regulated by base slip and prismatic slip. In compression of magnesium alloy samples, it was dominated by basal slip and {10–12} twinning. In all compression specimens, the grain c-axes are parallel to the compression axis regardless of the initial orientation. The r-values under different uniaxial strain paths have been also predicted by using the VPSC-TDT model. The negative r-values under uniaxial compression along RD to TD were further explained. The contribution of {10–12} twinning to plastic strain and the extra hardening induced by {10–12} extension twinning were discussed in depth. This study confirms that the extra hardening induced by {10–12} extension twinning will perform an important function when the twin volume fraction reaches a degree of about 50% with the active pyramidal slip at the same time.