Refill Friction Stir Spot Welding of Similar and Dissimilar Alloys:A Review

Refi ll friction stir spot welding, also known as friction spot welding(FSpW), is a solid-state welding process suitable for spot joining of lightweight materials. Through the eff orts of improving joint quality for similar and dissimilar materials, for example, aluminum and magnesium, this joining technology is well developed. The joining mechanism and process characteristics of FSpW have been widely studied. However, the application of FSpW in industry has not been entirely successful. In this review article, the research of similar and dissimilar material joints, such as, Al/Cu, Al/Ti, Al/Mg and Al/Steel, is summarized. The microstructural features and mechanical properties of the joints, welding tool and the application development are discussed in detail.