Microstructural Features of Dissimilar Thin Sheets Aging Aluminum Alloy – Low Carbon Steel Joined by Friction Stir Welding

The environmental crisis has raised serious concerns regarding fuel consumption, inciting a race to reduce vehicles’ weight. The design of structures combining different materials is a common factor in various industries, where the synergy between steel and aluminum is the starting point for many applications. Metallurgical challenges and the implementation of joining processes for thin sheets are some challenges that friction stir welding has overcome in the last two decades. In this manuscript, the methodology for joining aluminum alloy 6063-T5 and SAE 1020 steel, in thin sheets, employing friction stir welding, is presented. The research evaluated the offset in obtaining joints with complete joint penetration, heat generation, and microstructural changes. Joints with no defects were obtained, with a low thermal input, which favored the formation of tiny grain size in the stir zone, as well as an interface free of intermetallic compounds.