Influence of initial texture on the twin formation and plastic deformation of Mg-3Al-1Zn alloy

The effects of initial texture on the twin formation and plastic deformation of Mg-3Al-1Zn alloys which were manufactured by three different methods (hot rolling, ingot casting and strip casting, respectively) were investigated in this work. X-ray diffraction (XRD) experiment and electron backscattering diffraction (EBSD) analysis showed that a strong basal texture (implying that the basal planes of HCP lattice in grains were located parallel to the rolling direction) was formed in the rolled plate, while weak and random basal texture were formed in a strip cast sheet and cast ingots, respectively. To understand anisotropic properties of each material, two kinds of compression test specimens (RD and ND specimens) were machined from the three materials. Compression tests were carried out at room temperature with fixed strain rate of 0.01/s to various strain levels (0.05, 0.07, 0.12, 0.17 and 0.20). The results showed that twinning and deformation behaviour of Mg-3Al-1Zn alloy were strongly affected not only by the degree of textures but also by the specimen orientation. Electron backscattering diffraction (EBSD) analysis was also used to analyze twin systems formed after plastic deformation, to quantify the amounts of grains favorable for twin formation and to analyze texture evolutions during plastic deformation of three different materials.