Residual stresses in friction stir welding

Abstract: Residual stresses are always produced during welding and often cause problems, either due to distortion or performance degradation. this chapter provides an explanation of the origin of residual stresses during welding, how to measure them and potential problems that may arise due to them. General methods of residual stress mitigation, either through management or control, are discussed along with their applicability to friction stir welding. the effects of the friction stir welding process parameters on the residual stress profile are considered. the chapter concludes with examples of the application of active residual stress control systems using stress engineering methods during friction stir welding.