3D Material Flow in Friction Stir Welds

This study reveals the material flow that occurs as a function of position across a friction stir weld through an analysis of the deviations between the observed orientations of the shear deformation texture as compared to a model of idealized, geometrically predicted texture orientations at each location. Friction stir welding is a shear-dominated process, and the observed shear textures can indicate the local orientation of material flow during the welding process. Deviations of the observed texture from the geometrically predicted texture orientations reveal previously unreported variations in the actual material flow that occurred during welding as a function of position across the weld. The three-dimensional material flow revealed by these texture orientations shows important variations, particularly on the advancing side of the weld, that can provide critical experimental validation for friction stir welding models. [GRAPHICS] .