Twinning effects on the hot deformation behavior of AZ31 Mg alloy

• Extension, contraction and double twins were generated by the pre-compression before hot deformation.
• The nucleation and growth of DRXed grains near or in twins were characterized.
• Twinning-induced DRX behavior and mechanism were discussed.

Twinning plays an important role in the dynamic recrystallization (DRX) of AZ31 magnesium alloy. To evaluate the effect and the underlying mechanism of twinning, we studied the microstructure and texture evolution of pre-compressed extension twin (ET) and contraction twin (CT) samples under uniaxial compression at 250 °C at a strain rate of 0.001/s. The results suggested that favorable nucleation sites for DRX grains were contraction or double twin boundaries of CT sample rather than extension twin boundaries of ET sample. Based on the different textures in ET and CT samples after hot deformation, we demonstrate that the pre-existing twins can greatly affect the grain orientations of DRX grains such as in the case of CT sample where DRX grains exhibited new orientations after hot deformation.