Micro-texture-mediated dynamic hetero-deformation enabling high strength-ductility in a dilute Mg-Al-Ca-Mn alloy

Abstract

Micro-texture design of hard-/soft-oriented grains improves Mg alloys' mechanical properties, while strength-ductility trade-off persists due to insufficient early-stage strengthening from soft-oriented grains and later-stage strain coordination in hard-oriented grains. Here, a TD-spread basal-textured dilute Mg-1.27Al-0.38Ca-0.45Mn alloy architected by uniformly-mixed basal-/TD-/random-oriented grains was prepared by simple hard-plate rolling and short-time annealing. Interestingly, it features dynamic hetero-deformation as TD-oriented grains initially act as hard domains enhancing strength and later function as soft domains by activating multiple non-basal slips. Facilitated by such hard-to-soft transition of TD-oriented grains, a superior strength-ductility combination (yield strength of ∼218 MPa, elongation of ∼27.3%) was achieved.

Keywords

• Mg alloys
• texture
• deformation behaviors
• strain partitioning
• non-basal slips