An Experimental Study and Joining Parameters Optimization of Friction Stir Weld Butt Joint by Taguchi Approach to Maximize the Mechanical Properties

Friction stir welding is one of the solid-state welding to join the dissimilar alloys with elevated mechanical strength. In this experimental approach, the impact of process parameters on the mechanical characteristics of different metals or alloys formed by friction stir welding between AA5383 and AA7075 is determined, to optimize these parameters and to determine which ones are important using the Taguchi optimization procedure. The friction stir welding joints are generated experimentally at various factors of joining parameters, and that are rotational speed, feed and tilt angle of tool. The Taguchi approach has confirmed that the rotational speed is the most significant parameter than feed and tilt angle. The ANOVA shows that the selected parameters show individual and combined influence over mechanical properties. The prediction equation is proposed for predicting mechanical characteristics by using general linear model, and contour graph examination is employed for checking the effect of input parameters. The optimized joining parameters are determined for maximizing tensile and impact strength and minimizing the hardness of the welded specimens. The general linear analysis-based ANOVA approach has confirmed that the selected process parameters show combined and individual influence on impact strength. The optimized process parameters for maximizing tensile strength and hardness of the welded specimens are 1200 rpm of rotational speed, feed of 20 mm/min and tilt angle of 1.5°. The 1200 rpm of rotational speed, 60 mm/min of feed and 1.5° of tilt angle are the optimized process parameters for maximizing impact strength.