Repairing of exit-hole in dissimilar Al-Mg friction stir welding: process and microstructural pattern

The exit-hole is one major discontinuities in the friction based processes, where all the volume of the tool’s probe is missing with a depth that corresponds to the full thickness of the processed component. This letter presents a new technique to repair the exit-hole of an Al-Mg friction stir welding, without any third body material with inexpensive probeless tooling, inducing forging, stirring, and thermomechanical consolidation of the local spot joint. Intercalated banned type structures with interpenetrating features were achieved. Composite type mixed structure was obtained at repaired zone with a local tensile strength of 159 MPa.