Abstract—In the recent past, the scope for welding of aluminum alloys using FSW has increased. A nonconsumable tool is used to generate frictional heat in the abutting surfaces in which the shoulder and the pin are the important parts of the tool. Tool design is one of the most important and critical parameters that influence the FSW process as it determines the joint properties and microstructures. Tool pin profile, axial force, tool rotational speed, and welding speed are a few of the other important parameters that decide the weld quality. Physical FSW tools are manufactured using H13 (Chromium hot worked steel). Using each tool, friction stir welding process is carried out on two base materials AA6351 and AA6061 separately. The various process parameters are optimized by using the Design of Experiments (DOE) approach. As the stirring is the important phenomenon in the FSW, the quality of weld depends on how optimally the material is melted at the joint. A modified tool is designed and fabricated, which resulted in obtaining a better weld joint for the same combinations of parameters. The results obtained with the actual tool and modified tool are compared, and it is found that the results obtained by using the modified tool are much better

Index Terms—Friction stir welding, 6061 & 6351 aluminum alloy, Tool rotational speed, Welding speed, Axial force, Mechanical properties, Tensile strength, Modified tool

Cite: Indira Rani M and R N Marpu, "The Effect of Variation of Tool Geometry on Friction Stir Welded Aluminum Alloys-An Experimental Investigation," International Journal of Mechanical Engineering and Robotics Research, Vol.1, No. 1, pp. 91-98, April 2012.