Role and Effect of Friction Stir Welding Tool pin Profiles on Tensile Characteristics of Dissimilar Al6061-Al2014 Welded Joints

Abstract

Friction stir welding is a non fusion solid state welding technique where sheets are welded with application of frictional heat and pressure together. In this welding process, the tool pin geometry plays a crucial role for development of good quality welded joints. In this work, Al6061 and Al2014 aluminium alloy plates were welded with use of three different tool pin geometries such as straight square, straight hexagonal and taper threaded. Tensile properties and hardness of the welded joints were evaluated. From the results, the welded joints developed with straight square geometry tool tensile properties are better than the welded joint developed with straight hexagonal and taper threaded profiled tools. The better properties are due to pulsating action and higher dynamic volume to static volume ratio of the straight square geometry tool. A microstructural evaluation revealed that formation of more homogeneous distribution throughout the weld nugget for the welded joint made with straight square geometry pin tool.