Effect of tool pin profile on mechanical and microstructural properties of cooling assisted friction stir welding of AA6063-T6 weld joint.

Experiments have been performed in air and cooling-assisted condition with three tool pin profiles i.e. square, triangular and threaded cylinder. In this study, an effort has been made to comprehend how the mechanical characteristics, micro-hardness, and microstructure of friction stir welded AA6063-T6 joints are affected by in-process cooling, tool profiles, tool dimensions, and process parameters. For friction stir welding with cooling assistance, process parameters were optimised. For higher tensile and impact strength, a square tool profile with a shoulder to pin diameter ratio of 3:1 is found to be the most effective. The most important welding parameter was found to be rotations per minute (rpm). Microstructural analysis reveals finer grain size and a significant increase in microhardness in the weld nugget zone with cooling assisted FSW. [ABSTRACT FROM AUTHOR]