Crystallographic textures formed in friction stir welding
The paper studies the crystallographic textures formed in friction welding with mixing of materials differing in crystal lattice (face-centered cubic, body-centered cubic, and hexagonal close-packed) and in stacking fault energy. It is found that simple shear textures dominate, though some cases reveal recrystallization textures. It is shown that decreasing the stacking fault energy in fcc metals weakens the texture and changes its type from B/B¯ {112} to A/A¯ {111}. In welding of Mg alloys, there arise exceptionally strong textures whose intensity can be up to 54 times higher than the background level. Texture analysis reveals the following prevailing slip patterns in welding: slip along the plane {112} for bcc metals; basal slip for Mg alloys; prismatic slip for Ti; and concurrent basal and prismatic slip for Zr.