Simulation of mechanical behavior of AZ31 magnesium alloy during twin-dominated large plastic deformation

Experiments and visco-plastic self-consistent (VPSC) simulations were used to quantify the amount of twinning and the relationship to stress-strain behavior in a textured Mg-3Al-1Zn plate. Two different compression directions were utilized to favor {1 0 1¯ 2} extension or {1 0 1¯ 1} compression twinning. {1 0 1¯ 2} twins nucleate at the beginning of plastic deformation and grow to consume the parent grains completely. During compression along the normal direction, {1 0 1¯ 1} twinning and {1 0 1¯ 1}-{1 0 1¯ 2} double twinning start at strain of 0.05, and the number of twins increases until rupture, above strain of 0.15. {1 0 1¯ 1} and {1 0 1¯ 1}-{1 0 1¯ 2} twinning also occur during compression along the transverse direction, start at strain of 0.06 and then multiply in grains totally reoriented by {1 0 1¯ 2} twins. Using suitable parameters, the VPSC model can accurately predict the occurrence of extension, compression and double-twinning as well as the flow stresses and deformed textures. According to VPSC simulations, twinning and slip have the same latent hardening parameters.