Recent advances in dissimilar welding of aluminum and magnesium alloys with emphasis on interfacial adhesion

The demand for high-strength, lightweight, multi-material structures and corrosion-resistant materials has accelerated the adoption of magnesium and aluminum alloys in marine engineering, automotive, and aerospace industries. Achieving reliable joints between these dissimilar alloys remains challenging due to their distinct metallurgical and physical properties, particularly the tendency to form brittle intermetallic compounds (IMCs). Friction stir welding has developed as an attractive solid-state joining process for aluminum-magnesium alloys. The tensile strength of dissimilar Al/Mg joints was reached up to 65% to 85% of the weaker base metal under optimized conditions, while excessive input heat promotes the materialization of brittle IMC layers of 4–25 μm, leading to a 30%–40% reduction in the joint efficiency and premature failure. This paper fills the gap in previous analyses of microstructural interfaces, joint strength, and welding parameters. It was observed that various works have focused on the mechanical properties and metallurgical characterization of Al/Mg welded joints. This review identifies critical research gaps and proposes future directions on controlling IMCs formation, optimizing process parameters, and developing an advanced FSW process to produce sustainable and durable Al/Mg dissimilar joints for various industrial applications.