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Tailoring recrystallization via particle-stimulated nucleation (PSN) and pinning effects from secondary phase particles effectively weakens textures, which is still challenging for low-alloyed rare earth-free Mg alloys. Herein, the texture of a dilute cold-rolled Mg-2.2Al-0.33Ca (wt.%) alloy is found to reduce with the appearance of transverse direction (TD) texture components during static recrystallization. The texture transition is mainly attributed to the preferential growth of TD-oriented recrystallized grains, resulting from the preferential segregation of Al and Ca atoms on basal-oriented grain boundaries with low misorientation angles. The findings provide an in-depth understanding of texture modification in Mg alloys. The anisotropic co-segregation of Al and Ca on grain boundaries is responsible for the texture weakening of a dilute Mg-Al-Ca alloy, which provides a strategy for texture modification in such alloys.

Achieving high strength-ductility synergy in hard-to-deform high-alloyed Mg-Gd-Y-Zn-Zr alloys by rolling remains a great challenge. In this work, a Mg-8.2Gd-3.8Y-1.0Zn-0.4Zr (wt.%) alloy sheet possessing a high yield strength (YS) of ∼385 MPa, ultimate tensile strength (UTS) of ∼420 MPa and elongation of ∼19% was achieved via a single-pass hard-plate rolling (HPR) process. The high YS is mainly from amounts of submicron FGs and strong interactions between densely distributed γ′ precipitates and pyramidal dislocations in CGs. The activation of multiple slip systems, HDI-hardening effect, and crack suppression effect from γ′ particles, endow the excellent ductility. The hard-to-deform WE94 alloy sheet exhibiting a superior strength-ductility synergy has been prepared by a single-pass HPR process. The bimodal grain structure containing substantial ultrafine grains coupling with inhomogeneously-distributed nano-scale precipitates accounts for the superior mechanical properties.

By introducing heterogeneous lamella-structure, we obtained a superior strength-ductility synergy in Mg-alloy associated with excellent strain-hardening ability, i.e. yield strength of ∼251 MPa, tensile strength of ∼393 MPa and elongation of ∼23%. By using advanced characterization techniques, we showed that strengthening was mainly caused by the non-uniform distribution of hetero-deformation induced (HDI) stress associated with grain-boundary disclinations, which are mediated by heterogeneous multi-grain interactions. Induced by grain-boundary disclinations and intergranular slip transfers, a variety of abnormal deformation modes have been activated，which contributed significantly to enhanced ductility. This work suggests a new avenue to evade strength-ductility trade-off dilemma in Mg-alloys. The heterogeneous lamella-structure leads to sustained strain-hardenability in Mg-alloy with unique accommodating deformation modes (extensive abnormal slips and feather-shaped twins), induced by grain-boundary disclinations and intergranular slip transfers.