Evolution of microstructure and texture of AZ31 magnesium alloy during hot-rolling process

Abstract

The single-pass hot-rolling was processed on the cast-rolled sheet of AZ31 magnesium alloy. The evolution of microstructure and texture was studied with OM, TEM and XRD. The results show that the cast-rolled sheet has a strong basal texture, and the main deformation mechanism is twinning in hot-rolling with small reduction while the dislocation slip becomes the main deformation mechanism in hot-rolling with large reduction. The thick lenticular {101̄2} twins generated in 10% hot-rolling process seriously weakens the basal texture, while two types of twins {101̄2} and {101̄1}-{101̄2} with different morphologies are produced in 20% rolling process. As the rolling reduction exceeds 20%, the dislocation slip is activated in a wider range, thus intensifying the basal texture. And the fragmentation morphology produced in the rolling process transforms to equal-axis recrystallization grains in following annealing.