Optimization of friction stir welding AA6082-T6 parameters using analysis of variance and grey relational analysis

Abstract

Friction stir welding (FSW) is a solid-state welding process, which has a significant role in solid-state welding processes for nonferrous alloys. Conventional arc welding processes for aluminum alloys such as metal inert gas (MIG) and tungsten inert gas (TIG) are replaced by FSW. The effect of FSW parameters such as rotational and traverse speeds, tool geometry, plunge depth, tilt angle, etc., on weld quality were considered in several optimization studies. Hence, the effect of fixture position is included in this study. Multi-criteria decision-making (MDCM) techniques such as grey relational analysis (GRA) were used to determine the optimal condition among experimental runs designed by response surface methodology (RSM). The Taguchi method was widely applied with MCDM techniques. Therefore, the experiments were conducted according to response surface methodology. Input parameters were (14, 16 and 18) mm for shoulder diameter (SD), (0.0, 0.2 and 0.4) mm for plunge depth (PD), and (30, 60 and 90) mm for fixture position (FP), which is the distance between fixture bolts used to fix the welded plate. The results obtained by GRA were similar to the ANOVA optimizer, and the optimum process conditions are shoulder diameter of 14 mm, plunge depth of 0.2 mm, and fixture position of 60 mm.