Microstructure, texture and mechanical anisotropy of Mg-Gd-Y-Zr sheets processed via different rolling routes and reductions

Abstract

The dependence of microstructure, texture and mechanical anisotropy of Mg-Gd-Y-Zr alloy sheets on rolling routes (unidirectional rolling (UR) and cross rolling (CR)) and reductions (10% and 30% pass reduction) was investigated. Results show that the rolled sheets with pass reduction of 10% mainly consist of coarse deformed grains and 101¯2101¯1 tensile twins, and the UR sheet possesses twins with larger size and higher area fraction. With pass reduction increased to 30%, dynamic recrystallization (DRX) occurred in both UR and CR sheets, therein the CR sheet exhibited the lower DRX ratio due to the high degree of dynamic recovery induced by the CR route. Meanwhile, texture and deformation modes of the rolled sheets also exhibit rolling reduction dependence. For the case of 10% pass reduction, CR and UR sheets show the similar basal texture type and intensity, and thus prismatic ⟨a⟩ slip dominates plastic deformation during tensile tests. For the case of 30% pass reduction, CR sheet possesses a multiple-peak texture with more obvious peak inclination and spreading, while UR sheet shows a single-peak and weaker basal texture. The difference in texture results in the difference in deformation modes during tensile tests, i.e., prismatic ⟨a⟩ slip for UR sheet and basal ⟨a⟩ slip for CR sheet, respectively. Above differences further bring distinction to the mechanical anisotropy of the rolled sheets. For 10% pass reduction, CR and UR induce similar anisotropy. For 30% pass reduction, CR causes a more significant anisotropy than UR.