Studies on friction stir welding of Dissimilar aluminium alloys Aa5083 h111 and aa6061 t6 for deep Ocean applications

Abstract

Friction Stir Welding (FSW) is a solid - state joining technique of recent origin in the area of metal joining processes. It is an emergent green technology known for its energy efficiency (low heat input), sustainable utilization of natural resources (less material waste and better weld quality) and having lower environmental hazards (avoidance of shielding gases and filler material addition, occurrence of fumesetc). Aluminum alloys are mainly composed of an aluminum element and a moderate amount of magnesium, manganese, silicon and chromium elements. They find use in marine and sub-sea applications due to their corrosion resistance, high strength to weight ratio and wear resistance. AA5083-H111 is one type of aluminum alloy majorly used in the fields of marine related industries and chemical industries because of good corrosive resistance and resistance against chemical attack. AA6061-T6 is another type of aluminum alloy used for general applications and has better weldability characteristics. In this investigation, aluminum alloy materials AA5083-H111 and AA6061-T6 were welded by using the friction stir welding (FSW) method and the microstructure and mechanical properties of the welded joint were analyzed for deep ocean applications. Welding process parameters were optimized using the Taguchi technique based on the experimental work carried out on the AA5083-H111 AA6061-T6 dissimilar aluminum alloy joint. FSW process parameters namely, the Rotational speed, Transverse speed and Tool pin shape were chosen as input parameters and the tensile strength and hardness taken as output parameters, for arriving at the optimal parameters which result in a sound weld joint newline