Effect of Tool Shoulder and Pin Cone Angles in Friction Stir Welding using Non-circular Tool Pin

In friction stir welding frictional heat is generated by the rotating tool, sliding over the stationary plate along the weld centre. Tool being the only source of heat producing member, its geometrical design influences the heat generation rate. In this present work, effects of variation in tool shoulder and tool pin taper angles on thermal history during joining are analysed. Tools with triangular and hexagonal tool pins are used to understand the influence of tool pin shape on process temperature. An analytical heat input model is developed for tools with non-circular tool pins and a comparative study is carried out between the hexagonal and triangular tool pins on temperature distribution using a three dimensional Matlab model. Proposed model is validated through experimental analysis. Apart from this, regression model based comparative study is carried out on the variation in temperature response to the change in tool pin shape, tool shoulder and tool pin taper angle.