Insights into the texture-dependent strain hardening mechanisms of conform-processed AZ31 Mg alloys: Experimental investigations and VPSC modeling

The texture in magnesium (Mg) alloy affects dislocation nucleation and slip transfer, strain distribution (deformation uniformity), which lead to complex strain hardening behaviors. Basal texture-induced anisotropy has long limited the formability and strain hardening of Mg alloys. In this work, the Conform process, characterized by intense shear deformation and continuous self-heating, was applied to forge, shear, and recrystallize the grain orientations of an AZ31 Mg alloy. The origins of texture evolution and its roles in strain hardening were investigated by integrating multiscale experiments with visco-plastic self-consistent (VPSC) modeling. The results demonstrated that the pronounced basal texture, together with the bimodal grain size distribution in the as-received alloy, imparted a higher yield strength but constrained its strain-hardening capability. The Conform-processed alloy, with a texture inclination angle of 64°, exhibited a synergistic deformation mode, characterized by stronger basal slip, earlier and sustained 〈c + a〉 activity, and increased twin participation that collectively accommodated plastic deformation. This synergy increased dislocation density, with a significant rise in the proportion of 〈a〉 dislocations (from 81.9% to 92.1%) and 〈c + a〉 dislocations (from 18.1% to 40.9%) after Conform processing. These changes in dislocation populations enhanced slip–twin transfer, leading to lower yield strength but improved strain-hardening capacity and tensile ductility. These results demonstrated that Conform process provided an effective strategy for tailoring texture-dependent deformation mechanisms and manufacturing Mg alloys with enhanced strength–ductility synergy.