Research Progress in Friction Stir Solid-State Welding and Additive Manufacturing of Copper-Aluminum Transition Components

Copper-aluminum components have significant application value in electrical power and transportation field. However, due to the differences in the physical and chemical properties of copper and aluminum, a large number of brittle intermetallic compounds (IMCs) at the joint interface tend to be formed when the conventional fusion welding methods are used. Which leading to severe degradation of joint performance and limiting the reliable application. As advanced solid-state joining and forming techniques, friction stir welding (FSW) and friction stir additive manufacturing (FSAM), characterized by low heat input, can effectively suppress the formation of IMCs, offering a feasible method for producing high-performance copper-aluminum components. This paper systematically reviews the relevant research progress, analyzes the process principles, technical characteristics, and application prospects, and identifies current major challenges. Furthermore, the mechanical properties, electrical properties, thermal properties, and corrosion resistance of the joints are discussed and the formation mechanisms and control strategies of IMCs are summarized. Finally, the future development directions of FSW and FSAM technologies for copper-aluminum components are discussed.