Measurement and Prediction of Residual Stresses in Aluminium Friction Stir Welds

Friction stir welding (FSW) is a solid-state process that offers the possibility of creating high quality joints between dissimilar aluminium alloys. However, to date little is known about the distribution of residual stresses within such joints. In this study, a combined modelling and experimental approach has been undertaken in an attempt to clarify this situation and develop a practical predictive tool. The model appears to have captured the asymmetry of the welding process but the peak residual strain is typically 30% higher than measured by synchrotron X-ray diffraction indicating that some optimisation is required.