Twin-Slip Interaction at Low Stress Stage Deformation in an AZ31 Mg Alloy

Extruded magnesium alloys with strong basal texture present tension and compression asymmetry. Dislocation slip dominates plastic deformation during tension along the extrusion direction (ED), whereas twinning is the main contributor to plastic strain when compressed along the ED. In this work, an extruded AZ31 Mg alloy was prestrained by tension along the ED to 5 and 10% of total strain, followed by compression, in order to investigate twin-slip interaction. The results show that the yield stress in compression only slightly increases with increasing prestrain. Notably, the hardening rate at the low stress stage during compression remains almost unchanged, compared to specimens without prestrain. Our results suggest that the contribution of twin-slip interaction to hardening is negligible in deformation of Mg alloys.