Investigate The Friction Stir Welding Joint Of Magnesium And Aluminum Alloys

Abstract

Aluminum alloys of series 6xx.x and magnesium alloy of series AZXX are facing defects whilewelding by traditional methods. The common practice of joining these alloys is Tungsten inert gas welding and Metal inert gas. Promising technology of friction stir welding (FSW) has been invented in 1991 and shows tremendous results in welding of aluminum and magnesium alloys. In this thesis after selection of base material AA6061(A) aluminum alloys and AZ31(B), AZ91(C) Magnesium alloys process parameters is selected to perform Friction Stir Welding. Process parameters are selected from range 1000, 1200 and 1500 rpm of rotational speed and welding speed from range 14, 20, 24 m/min. 1200 rpm rotational speed and 24m/min welding speed shows defect free butt joints after trails.Selection of joint was observed on the behalf of application (Efficiency, Cost, Safety) of automobile. Friction stir welding performed on similar (AA, BB, CC) and dissimilar alloys (AB, BA, BC, CB, AC, CA) joints with non-consumable H-13 tool. The study aimed to investigate the microstructure, corrosion properties and mechanical properties like tensile strength, impact strength, and hardness. Fractography were performed on failure tensile specimen to reveal the nature of failure for quality analysis. It was performed on scanning electronic microscopy (SEM). One way ANOVA post-hoc tukey test was applied for multiple comparisons among three base metals, three similar and six dissimilar butt joints. Analysis concluded that mechanical and corrosion properties were improves significantly.Microstructure was observed on optical microscope for qualitative analysis. Maximum hardness was observed in base metal A (107Hv), in similar joint AA (110Hv) and in dissimilar joint AB (114Hv). However, maximum tensile strength was observed in dissimilar joint CB (192.39MPa). Base metal A has maximum impact strength 14.90 J while its joint showed decline trend and maximum was observed in similar joint AA (9.60J). Based on corrosion rate, the minimum corrosion rate was obs