Optimization of Process Parameters of Friction Stir Welded Joint of Aa2024 and Aa7050 by Response Surface Methodology (RSM)

The friction stir welding of dissimilar aluminum alloys AA2024 and AA7050 was performed by the central composite design (CCD) technique by response surface methodology. Three process parameters i.e. traverse speed (TS), tool rotational speed (TRS), and tilt angle (TA) have been investigated by conducting experiments by CCD. The empirical correlation between input and output responses (tensile strength, micro-hardness, and elongation) has been developed through response surface methodology by designexpert software. The developed models reveal that the TRS and TA have a more dominating effect on the output responses. ANOVA table was employed to check the adequacy of the developed model at 95% confidence level. It was found that the FSWed joint with TRS 1300 rpm, TS of 30 mm/min with tilt angle 2º exhibited the maximum tensile strength. The adequacy of the developed models was validated by the ANOVA technique. The results observed from the confirmatory experiments plotted in the scatter diagram shows agood agreement with the predicted models. The optimized tensile strength (244.74 MPa), % elongation (23.52), and micro-hardness (102.63) was observed at TRS of 1216.56 rpm, TS of 36.71 mm/min and TA is 1.22°.