Aluminium 6061 alloy is commonly used for construction of aircraft structures, such aswingsandfuselages, more commonly in homebuilt aircraftthan commercial or military aircraft.Aluminium 6061 alloy generally present low weldability by traditional fusion welding process. The development of Friction Stir Welding (FSW) has provided an alternative improved way of satisfactorily producing weld joint in aluminium 6061 alloy. In FSW, the welding tool motion induces frictional heating and severe plastic deformation and metal joining process is done in solid state results, which results in defect free welds with good mechanical properties in aluminium alloy 6061. Unlike in traditional fusion welding, friction stir welds will not encounter problems like porosity alloy segregation and hot cracking, and welds are produced with good surface finish. In this paper, an attempt was made to investigate the impact of process parameters of FSW in the mechanical properties of the joint. The tensile properties, microstructure, hardness of the FSW joints were investigated in the weldment and heat affected zone. The changes of mechanical properties are compared with the parental metal. The welding parameters such as tool rotational speed and welding speed plays a major role in deciding the joint characteristics. This paper focuses on optimization of all these parameters. From this investigation it was found that the joint made from the FSW yielded superior tensile properties and impact strength due to the higher hardness and fine microstructure.

FSW, Welding Speed, Axial Force, Mechanical Properties, Microstructure