Tool Offset Influence on Mechanical and Microstructure Properties of Dissimilar AL6082 and Copper Friction Stir Welded Joints

This work is to find the role of tool offset on mechanical and microstructural behaviour of Friction Stir welded of AA6082 and pure copperbutt joints. The major factors considered in this study are, tool rotation speed, tool travel speed and tool offset. The dissimilar butt welds are produced using cylindrical taperd pin by keeping the copper plates on advancing side of joint. Tensile and Bending tests are conducted to evaluate the strength of weld joints. Microhardness test is done in transverse direction of welds to evaluate the hardness distribution on weld nugget. Experimental investigation reveals that, at toolrotational speed»of 1000 rpm, tool travel speed of 24 mm/min and offset of 1mm towards aluminium side yields the better Tensile Strength of 121 Mpa, Bending Strength of 24.3 Mpa and Hardness of 100 HV are obtained at the nugget zone. Microstructure reveals that if more quantity of copper particles are present in the aluminium section at the stir zone, that attributes to good mechanical properties.