Modeling of Friction Stir Welding on Conventional Vertical Milling Machine and its Validation

Friction stir welding(FSW) is a solid state welding technique, it uses a rotating tool to generate the necessary heat for the process. FSW is initially used to weld aluminium and its alloys because the defects like porosity, alloy segregation, hot cracking, hydrogen entrapment etc. are not encountered with this process those are mainly appeared in fusion welding processes [1]. Process uses a non consumable rotating tool which slides along with rotation on the faying surface of work-pieces to be weld. To obtain the desired strength, it is essential to have complete control over the relevant process parameters on which the quality of a weldment is based. The process was duly named friction stir welding (FSW), and TWI filed for world-wide patent protection in December of 1991 by TWI. TWI (The Welding Institute) is a world famous institute in the UK that specializes in materials joining technology. Many of the typical problems related to fusion welding of aluminium alloys can be avoided by using non conventional joining techniques. Since FSW is governed by two completely mechanical processes, i.e. mixing and forging, it is possible to join heterogeneous aluminium alloys without filler metal. Using specially designed tools and machines up to 75mm of aluminium can be welded in a single pass. This paper describes a low-cost method of transforming a conventional milling machine into a simple FSW work station It is also a cleaner and more efficient process compared to conventional technique.