Optimization and analysis of microstructural friction stir welded AA5083 grade aluminium alloy

The present work is the novel approach to optimize the friction stir welding process of aluminium AA5083 alloy by utilizing Taguchi L9 orthogonal array technique. The present work also investigated the mechanical and metallurgical characteristics of the weld joint. The present work involved three input friction stir welding parameters that were varied in the investigation under the Taguchi L9 orthogonal array experimental methodology. The experimental methodology was utilized to predict the optimal input parameters to obtain peak tensile strength and hardness values of the welded joint and the signal to noise (S/N) ratio and results of the Analysis of variance (ANOVA) were also investigated. The optimal tool rotational speed, welding speed and tool tilt angle were 560 rpm, 60 mm/minute and 1 degree respectively for the peak joint tensile strength and 560 rpm, 80 mm/minute and 1 degree for peak joint hardness. The results from ANOVA indicated that the highest influencing input factor of the weld joint was tool tilt angle followed by the welding speed and tool rotational speed. Metallurgical analysis of the joint revealed fine grain structure within the stir zone which directly resulted in the enhancement of the weld joint properties.