An experimental and numerical study of texture change and twinning-induced hardening during tensile deformation of an AZ31 magnesium alloy rolled plate

The increase in flow stress due to work hardening, texture change and twinning has been examined using experiments and a crystal plasticity model. Samples with five different orientations were cut from a thick rolled plate of magnesium alloy AZ31 with a strong basal texture and subjected to tensile deformation. Samples elongated along the normal direction ND (0° samples) deformed mainly by tensile twinning, those deformed along the rolling direction RD (90° samples) deformed mainly by prismatic slip, and samples deformed along different angles from ND to RD (30°, 45° and 60° samples) deformed by both slip and tensile twinning. The mechanical properties and the observed microtextures were compared with the predictions of an original crystal plasticity model and to evaluate the strengthening induced by work hardening, texture rotation and twins. The analysis shows that the twin boundaries introduce additional Hall-Petch hardening that increases the CRSS of the hard slip systems by 30%.