SOME STUDIES ON FRICTION STIR WELDING OF Al 6082 ALUMINIUM ALLOYS

Abstract

Friction stir welding (FSW) is a relatively new solid-state joining process. This joining technique is energy efficient, environment friendly, and versatile. In particular, it can be used to join aluminium alloys and other metallic alloys that are hard to weld by conventional fusion welding. It is suitable for joining of Al alloys, Mg alloys, Cu alloys, Ti alloys, steel and joining of dissimilar metals and alloys. AA6082 is a heat treatable alloy with major alloying element is magnesium and silicon. In this study optimization of process parameters (tool rotational speed, welding speed, tool shoulder diameter to pin diameter ratio) for tensile strength and micro hardness of friction stir welded specimen was carried out. A mathematical model was developed for predicting tensile strength and micro hardness of friction stir welded AA6082 alloy using design expert software (version 6.0.5). Three factors, three levels central composite design have been used to minimize the number of experimental conditions. The developed mathematical relationship can be effectively used to predict the tensile strength and micro hardness of AA6082 alloy at 95% confidance level. These optimized parameters is further used to friction stir welding of AA6082 alloy with TiC nano particles. These TiC nano particles are added in welding zone during welding. Test result shows that inclusion of TiC nano particles enhances the weld strength and hardness.