Revealing Deformation Heterogeneity of an Aluminum Alloy During Friction Stir Spot Welding: An EBSD Investigation

Large electron backscatter diffraction area maps were used in the present work to characterize the microstructure and texture near the horizontal and vertical keyhole peripheries of the AA5182 alloy after friction stir spot welding. The findings demonstrate that the horizontal keyhole peripheric comprises a stirred zone (SZ) and a thermo-mechanically affected zone (TMAZ). The SZ started 300 µm away from the keyhole center and became thicker with increasing horizontal distance. The texture gradually changed from shear \({A}_{1}^{*}/{A}_{2}^{*}\) $A_1^{\ast }/A_2^{\ast }$ components at the SZ to rolling cube, goss, and brass components at the TMAZ. The vertical keyhole peripheric is mainly composed of SZ with an onion ring grain structure and is dominated by the C shear component.