Evolution of microstructure and hardness of aluminum after friction stir processing

The effects of friction stir processing (FSP) on the microstructure, microtexture and hardness of rolled pure aluminum were investigated. The microstructure and microtexture were characterized using electron backscattered diffraction (EBSD) technique on the transversal section. The stir zone (SZ) contains fine, equiaxed and fully recrystallized grains. The texture component of the base material mainly consists of R, S and brass R textures. Miner copper texture component is also determined. In the center of the stir zone, the dominant texture is (111) parallel to about 70° from ND pointing toward RD. The textures of this location rotating clockwise about 30° and anticlockwise about 60° around the ND result in the textures of the areas, which are 3 mm apart from this location on the retreating side and advancing side, respectively.