Optimization of process parameters of friction stir welded joints of dissimilar aluminum alloys AA3003 and AA6061 by RSM

The friction stir welding (FSW) has excellent potential compared to other welding processes for joining similar or dissimilar aluminium alloys, which operate severe plastic mixing and high temperature to enhanced the mechanical properties of aluminium alloys. In the present work, RSM was used for the mathematical modelling of the FSW input parameters to fabricate AA3003 and AA6061. The empirical correlation was developed to predict the output responses of the FSWed joints at 95% confidence interval (C.I). The developed model reveals that the tool rotational speed (TRS), and welding speed (WS) were the dominating parameters. The increase in TRS, and decrease in WS leads to increased heat input to the welded joints. The C.I reveals that the ultimate tensile strength (UTS), and microhardness increased with increasing TRS. The optimized value of UTS, % strain nad microhardness was observed as 95.8 MPa, 12.18%, and 74.47 HV, respectively, while the optimized value of TRS, WS, and tilt angle (TA) were 1172 rpm, 57.44 mm-min−1, and 1.252° respectively.