G. M. D. Cantin, CSIRO Manufacturing and Infrastructure Technology, Adelaide, Australia; S. A. David, E. Lara-Curzio, Oak Ridge National Laboratory, Oak Ridge, TN; W. M. Thomas, TWI, Cambridge, United Kingdom; S. S. Babu, Ohio State University, Columbus, OH

Summary: A variant of the friction stir welding technique called skew-stir^TM has been applied to the welding of lap joints in aluminium. Interfaces in the microstructure, formed by the compression and deformation of the original faying surfaces, were characterised, and their influence on the mechanical properties of the welds was assessed.