A Comprehensive Review on Fusion Arc Welding of Aluminum Matrix Composites: Challenges, Mechanisms, and Advancements

Aluminum Matrix Composites (AMCs) offer superior mechanical and tribological properties, making them attractive for advanced structural applications. However, challenges in joining techniques, especially fusion arc welding, hinder their broader industrial use. Fusion arc welding of AMCs, particularly using Tungsten Inert Gas (TIG), faces major challenges due to interfacial reactions, porosity, and reinforcement agglomeration. This review evaluates recent strategies to improve weld quality, emphasizing nano-composite filler metals, weld parameter optimization, and post-weld heat treatments. Composite fillers reinforced with TiB₂, TiC, graphene, and high-entropy alloys (HEAs) significantly enhance tensile strength and hardness through grain refinement, Orowan looping, and thermal mismatch strengthening. Among these, HEA-based fillers (10 wt%) demonstrate the best performance, achieving 410 MPa UTS and 22% strain. Post-weld aging and homogenization further improve microstructural uniformity and mechanical properties. Innovations such as artificial intelligence (AI)-based process optimization and hybrid welding are also discussed. This review provides a mechanistic synthesis of recent advancements and identifies promising pathways for overcoming critical welding challenges in AMCs, thus serving as a valuable reference for future research and industrial implementation.