Experimental investigation of Tool Geometry on Mechanical Properties of Friction Stir Welding of AA6061

AA 6061 has gathered wide acceptance in the fabrication of the light structures required to high strength. Compared to the fusion welding processes that are used for joining structural aluminium alloys, friction stir welding (FSW) process is an emerging solid state joining process in which the material that is being welded does not melt and recast. In this experimental work, an extensive investigation has been carried out on FSW butt joint. Welded joints were made with the help of tool made of high speed steel (HSS) alloy steel. Tools were of two different pin profiles viz. straight cylindrical, and square. The welded joints were made on aluminum grade AA 6061 plates of 6 mm thick. Tests were conducted to determine the tensile strength, percentage elongation and micro hardness. In my investigation, tool rotation and traverse speeds are kept constant i.e. 2000 rpm and 20 mm/min. The variables are shape of the tool and having passes one sided and both sided. Cylindrical tool pin profile exhibited superior tensile properties compared to other joints, irrespective of tool rotational speed in double pass. The joints fabricated by single pass have shown lower tensile strength and also percentage of elongation compared to the joints fabricated by double pass and this trend is common for all the tool profiles. Keywords-Friction Stir Welding (FSW), Aluminium AA 6061, Tensile strength