A state-of-the-art review on solid-state metal joining

This paper aims at providing a state-of-the-art review of an increasingly important class of joining technologies called solid-state (SS) welding, as compared to more conventional fusion welding. Among many other advantages such as low heat input, SS processes are particularly suitable for dissimilar materials joining. In this paper, major SS joining technologies such as the linear and rotary friction welding (RFW), friction stir welding (FSW), ultrasonic welding, impact welding, are reviewed, as well as diffusion and roll bonding (RB). For each technology, the joining process is first depicted, followed by the process characterization, modeling and simulation, monitoring/diagnostics/ nondestructive evaluation (NDE), and ended with concluding remarks. A discussion section is provided after reviewing all the technologies on the common critical factors that affect the SS processes. Finally, the future outlook is presented.