The impact of submerged friction stir processing on the friction stir welded dissimilar joints

Abstract The submerged friction stir processing (SFSP) technique was employed on the prior friction stir welded (FSW) AA6082/AA8011 dissimilar aluminum alloy joints. The tap water with room temperature was kept at 40 mm depth throughout the processing. The AA6082 was kept at the advancing side during FSW and SFSP process and this was done to enhance the strength of the joint. The SFSP joints were studied comparatively with the FSW joints. The sampling position was also studied for both the FSW joint and SFSP joint. The employment of the submerged friction stir processing resulted in the microstructural grain size refinement. The tensile strength of the SFSP joint was found to be higher than that of AA8011 base metal but lower than that of AA6082 base metal. The tensile strength of the FSW joint was found to be lower than that of both base metals. There was a clear correlation between the tensile properties and the grain size refinement. The SFSP joint exhibited good microhardness properties compared to the FSW joint.