Enhanced Yield Strength of Mg Alloys via Pre-shearing: Crystal Plasticity Insights on Loading Path and Texture Effects

The potential of magnesium alloys as lightweight structural materials has caught widespread attention owing to their exceptional balance of low density and mechanical strength. However, the process of producing high-strength magnesium alloys remains challenging. Pre-shearing, which induces a twinned microstructure, can alter the deformation characteristics of magnesium alloys and enhance their mechanical properties. This work investigates the influence of pre-shearing on subsequent tensile behavior of magnesium alloys, with a particular focus on yield strength enhancement. Building on experimental investigations conducted on AZ31 Mg alloy plates, a combined twinning–detwinning (TDT) framework and the elastic viscoplastic self-consistent (EVPSC) model are employed to model the subsequent tension along the different loading directions for the pre-sheared AZ31 plate with different textures. Our study reveals that the amount of pre-shearing has different effects on mechanical behaviors and yield strength enhancement for three initial textures. By adjusting the combinations of loading directions, initial textures, and the amounts of pre-shear strain with or without annealing, we can achieve various levels of yield strength enhancement. Additionally, the significant enhancement of yield strength for the pre-sheared material under subsequent tension along the 45 deg makes the pre-shearing a feasible method to optimize the wrought Mg alloy properties.