Study of Friction Stir Spot Welding of Aluminum/Copper Dissimilar Sheets using Taguchi Approach

Friction stir spot welding of dissimilar aluminum and copper sheets was investigated in details using Taguchi approach in this study. Analysis of variance was conducted to identify the effective parameters and their contributions on the mechanical performance. The findings revealed that the outputs followed normal distribution. The results indicated that the rotational speed with the contribution of 87.7% was the most effective parameter on the maximum tensile force tolerated by the welded samples. Dwell time and penetration depth were in second and third ranks from effectiveness viewpoint with the contributions of 8.8 and 2.9%, respectively. The results revealed that the maximum tensile force was significantly improved with the rotational speed. The maximum tensile force was enhanced by almost 228% by increasing the rotational speed from 550 rpm to 1500 rpm. Increasing the dwell time from 10 to 20 s led to improve the maximum tensile force by 31%.The sequence of the parameters was as rotational speed, dwell time and penetration depth from standpoint of influence on the maximum force according to the results of signal to noise ratio analysis. The signal to noise ratio analysis showed that the rotational speed of 1500 rpm, the penetration depth of 2.85 mm, and the dwell time of 20 s were the optimum conditions.