A Comparative Study of Mechanical Properties and Microstructures of FSW joints with Conventional welded joints
Energy savings and environmental preservation are important issues for us to resolve. Since reducing the weight of vehicles is one of the efficient measures, the use of the combination of steel and aluminium alloy has been increasing in fabricating vehicles. Under this situation, many trials to weld steel to aluminium alloy have been conducted. However, sound joints have not been produced so far, because hard and brittle intermetallic compounds were formed at the weld whenever steel was welded to aluminium by fusion welding. In gas welding process the metals get heated and due to the heating of the metal the strength of the metal decreases and also the microstructure of the metal changes. But in friction stir welding the metal gets less heated compared to the gas welding process. Due to the less heat absorbed by the metal the strength and microstructure changes comparatively less than the gas welding process. So comparatively friction stir welding gives accurate microstructure and tensile strength than the gas welding process. In the present work we tried to compare the micro structure, micro hardness and tensile strength of two Friction Stir welded joint with the gas welded joint. Keywords Friction Stir Welding (FSW) Al alloys, mechanical properties, microstructure.