Twinning and recrystallization behavior of AZ31 Mg-rolled sheets during the corrugated wide limit alignment process

Abstract

In this study, tensile twins (TTs) were induced in hot-rolled AZ31 Mg sheets via the corrugated wide limit alignment (CWLA) process. The microstructure evolution demonstrated that, compared to the as-received AZ31 Mg alloy sample, the twinned sample exhibited a rolling direction-tilted texture with {101‾2} TT boundaries in the 15–23% range. Moreover, distinct twin variants appeared in the matrix grains. Dynamic recrystallization (DRX) occurred during CWLA treatment when the temperature reached 300 °C, and a refined microstructure was formed. Discontinuous DRX was the primary mechanism observed during the CWLA process, and twin-assisted DRX was also initiated in the deformation stage. After CWLA deformation, the formability was improved. The 0.2% yield strength decreased by 46 MPa, the ultimate tensile strength increased by 30 MPa, and the fracture elongation remained the same as that of the annealed as-received samples, all of which resulted in enhanced formability of the alloy sheets.