Influence of ridges shoulder with polygonal pins on material flow and friction stir weld characteristics of 6082 aluminum alloy

Abstract

In the present paper, the flow of stirred material under ridges shoulder combined with various polygonal pin profiles during friction stir welding (FSW) of 6082 aluminum alloy was investigated through marker insert technique. The marker inserts (copper) were placed in ‘parallel to/along the weld’ and ‘perpendicular to weld configurations’. The axial force and tool torque during the welding were measured and compared for all the tools. Final weldments were subjected to radiographic and sectioned macro and microscopic observation to understand the detailed flow of marker material. The results show that the material driven by pin moves from bottom to top which improves the flow in the top layer of material i.e., shoulder region. The individual effect of pin profiles on material flow was clarified. The welds with square pin tool, (TR)S resulted in superior mechanical properties and uniform weld zone hardness with complete mixing and distribution of material on both advancing side (AS) and retreating side (RS).