Dissimilar micro friction stir welding of ultra-thin Mg AZ31 to Al 6061 sheets

We report the first successful work on micro friction stir welding (μFSW) between ultra-thin (500 μm) Mg AZ31 and Al 6061-T6 alloy sheets. The process resulted in a defect-free fully consolidated butt weld with regions of refined grains and strong metallurgical interlocking. Prepared joints evaluated under tensile testing showed joint efficiency of 54.5% with respect to AZ31 base material. Fracture under tensile testing occurred in stir zone/thermomechanically affected zone interface on Mg advancing side owing to the presence of intermetallic compounds. The prepared joints would have significant potential for structural applications in micro-assemblies and battery packs.