Innovations and Challenges: A Review on Additive Friction Stir Deposition of Aluminum Alloys

Additive Friction Stir Deposition (AFSD) is an emerging solid-state advanced manufacturing process with significant promise for aluminum alloys due to its ability to avoid solidification defects and enable sustainable fabrication, repair, and recycling. Despite rapid progress over the past decade, a comprehensive understanding of how AFSD process parameters govern the microstructure and properties remains fragmented, particularly in relation to precipitation behavior and mechanical performance. This review highlights a decade of research progress in AFSD of aluminum alloys since its invention in 2014, bridging experimental findings with modeling efforts and highlighting process–microstructure–property relationships. It also systematically reviews how variations in process parameters influence the material’s microstructure and hence determine the final properties. By critically evaluating progress and challenges, this review provides a roadmap for researchers and industry practitioners to guide future innovations, ensuring AFSD’s broader adoption across diverse applications.