Development and Analysis of Butt and Lap Welds in Micro-friction Stir Welding (μFSW)

Manufacturing of the ever smaller components, be it mechanical, electronic, etc., is being chased now a days. Likewise in friction stir welding (FSW), when the thickness of the joining plates is reduced to less than 1 mm, i.e. micro-friction stir welding (mu FSW), the application areas relate to joining thin-walled structures in electrical, electronic and micro-mechanical assemblies and in the packaging industry. The advantages of FSW like it being a solid state process, it not requiring any shielding gases or fluxes and its possibility to weld dissimilar and different thickness alloys emphasize the use of it to weld micro-thickness plates. In the present work, commercial grade AA6XXX series aluminium alloys of thickness 0.44 mm have been welded together in both butt and lap fashion. Tests have been conducted to measure the joint's tensile strength (by conducting both transverse and longitudinal tension tests) and the micro-hardness. The use of lap welds in application areas of mu FSW has been established.