Conventional Friction Stir Welding and Bobbin Friction Stir Welding for Joining Space Grade Aluminium Alloy 6061-T6 by an Industry-compatible Way: A Comparative Study

Abstract

Friction Stir Welding (FSW) is a modern solid-state joining process. It joins materials without allowing them to melt, with minimal change in their properties. There are multiple types of FSW based on the method of implementation. In the current study, the two most common techniques of FSW, known as Conventional Friction Stir Welding (CFSW) and Bobbin Friction Stir Welding (BFSW), are employed to fabricate butt joints of space-grade aluminum alloy 6061-T6 by utilizing the conventional milling machine, in-house development of FSW tool and heat treating the high temperature steel (H-13) using low cost steel foil method. Two different types of tools were manufactured, heat treated and FSW was performed. The comparison of the properties attained by the butt joints are presented in this study. Two welds were successful out of four successful experiments performed, which were found to contain an average tensile strength of 128 MPa along with 65-97% of average base metal hardness. It was also concluded that BFSW is more reliable for longer joints.