Feasibility of Underwater Friction Stir Welding and Its Optimization Using Taguchi Method

In this paper we are approaching to the feasibility of underwater friction stir welding of aluminum alloy which widely has the various applications where strength to density ratio plays a crucial role such as in marine, aircraft and automobile industries. The problems associated with joining of parts through conventional welding method is overcome by use of friction stir welding process yet the friction stir welding encloses the problems such as rapid tool wear especially during plunging period of tool, softening of the weld nugget formed due to decreased rate of cooling hence formation of precipitates takes more time which causes the mechanical properties such as strength, hardness etc are reduced and dissimilar base materials with considerable difference in their melting points are still a challenge to be welded by the present process . To overcome the above difficulties of the modified form of process of friction stir welding is used hence the whole process is performed under water i.e Underwater friction stir welding is used now a days.