Acoustic emission–based monitoring approach for friction stir welding of aluminum alloy AA6063-T6 with different tool pin profiles

Friction stir welding process is one of the solid-state welding processes, which is suitable to weld a range of similar and dissimilar material combinations by moving a shouldered, rotating tool along the joint line of weld materials. In this work, friction stir welding tools with square, circular, and triangular pin profiles are used to join the aluminum alloy AA6063-T6 flat plates. Acoustic emission technique is applied to monitor and analyze the effect of tool pin profile on tensile strength of the weld joints. A correlation study was made between the different acoustic emission signal parameters with the tensile strength of the weld joints. The proposed approach will be useful for in-process monitoring and control of the weld quality in friction stir welding process.