Optimization and Characterization Studies of Dissimilar Friction Stir Welding Parameters of Brass and Aluminum Alloy 6063 Using Taguchi

This paper focuses on optimizing process parameters such as tool rotating speed, preheat-treated workpiece temperature, traverse speed, and tool pin profile for dissimilar friction stir welding (FSW) of brass and AA 6063. The hardness of the friction stir-welded joint created is measured as a response variable. The Taguchi design of experiments approach was utilized to finalize the experimental strategy, and ANOVA was employed to analyze the data. The best input factors for a better weld and a harder FSW workpiece were predicted. The experimental results show that the input factors influenced the hardness and defects in the welds in the following order: tool rotation speed (28.98%), tool pin geometry (22.30%), travel speed (11%), and temperature of the preheat treated workpiece (10.95%), respectively. Optical microscopy identified three distinct zones: the nugget zone, the thermomechanically affected zone, and the heat-affected zone. The nugget zone had a maximum value of hardness (around a 27% increase) due to the formation of very fine recrystallized grains.