Strain path dependence of texture and property evolutions on rolled Mg-Li-Al-Zn alloy possessed of an asymmetric texture

Abstract

The influence of different rolling paths on the texture and property evolutions of extruded Mg-3Li-3Al-Zn alloy sheet possessed of an asymmetric texture was investigated, aiming to explore appropriate process to minimize the planar anisotropy of the sheet. The results indicated that the sheet exhibited quite different texture and property evolutions during undergoing different rolling paths, which was mainly due to the extremely deflected basal poles (nearly titled towards to TD). When the rolling process was conducted along its extrusion direction, the pyramidal 〈c+a〉 slip was easily activated, which would lead to strong re-orientation of the a-axis but limited rotation of the c-axis. As a result, the extremely asymmetric texture feature was retained during the subsequent recrystallization annealing and this type of texture modification showed weak effect on improving the planar anisotropy of the sheet. However, when the sheet was rolled along its transverse direction, the {101¯2} extension twin would became the dominated deformation mechanism, which led to sufficient re-orientation of the c-axis by almost 90°. Finally, a symmetric weak texture was introduced during subsequent annealing. This modified symmetric texture distribution along with the efficient microstructure refinement would give rise to accordant deformation behaviors during loading along different directions and thus could minimize the planar anisotropy of the sheet significantly, as well as improve the comprehensive mechanical properties.