| In this work, the experimental techniques including Electron Backscatter Diffraction (EBSD), Optical Microscope (OM) and Axial Extension Test were employed to study the features of microstructure, micro-texture and mechanical properties of FSP and FSW of AZ31magnesium alloy sheets for different initial textures, to explain the reason of the deformation inhomogeneity during a axial extension test using basal slip and extension twinning. And to investigates the influence of welding parameters on microstructures , microscopic textures and mechanical properties of FSW sheets for different initial textures. The main results are as follows:â‘ The initial texture had no obvious effect on the texture evolution of the stir zone (SZ), but it affected the texture of the thermo-mechanical affected zone (TMAZ) significantly.â‘¡The difference in the transverse tensile properties of the AZ31 sheets with different initial texture was reduced after friction-stir processing and welding because similar texture distribution was formed in the SZ. The grains in the center of the SZ were in preferential orientations for basal slip and extension twinning, whereas the grains in the side of the SZ were not, which resulted in inhomogeneous plastic deformation through the SZ.â‘¢The initial texture had little influence on the weld strength of friction-stir welded AZ31magnesium alloy sheets.â‘£The weld strength and the fracture location were different for the AZ31 sheets friction-stir welded with different welding parameters (rotation speed and traveling speed). The weld strength of the AZ31 sheet welded with relatively lower welding parameters was ~78% of the base material, and the fracture located at the interface of the TMAZ and the SZ at the advancing side. For the AZ31 sheets welded with relatively higher parameters, the tensile strength was comparable with the base material, and the fracture located at the base material area.
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