Modelling and optimization of submerged friction stir welding parameters for AA6061-T6 alloy using RSM

This paper demonstrates submerged friction stir welding (SFSW) of the AA6061-T6 alloy at optimized water head for achieving higher tensile strength. The experiments were conducted based on three factors, three levels, and the Box-Benham design with the full replication technique, which is used to minimize the number of experiments. The three factors considered are the tool rotational speed (rpm), welding speed (mm min(-1)) and water head (mm). The effect of these factors on the weld of AA6061-T6 was analysed, using response surface methodology (RSM), and a mathematical model was also developed to optimize the submerged friction stir welding process parameters to attain the maximum tensile strength of the joint. The experimental results confirmed the effectiveness of the method. Finally, the temperature distribution and grain size were investigated under the optimized conditions.