Experimental analysis and optimization of friction welding parameters for joining dissimilar materials through design of experiments

Friction welding (FW) has emerged as a promising approach for joining materials that are traditionally difficult to weld together due to their distinct properties. This research delves into the optimization of FW parameters for joining two commercial materials: Stainless Steel (SS) and Mild Steel (EN3B). This study investigates the optimization of FW parameters for joining SS and EN3B, aiming to achieve the Ultimate Tensile Strength (UTS), maximum Upset (UP), and optimal Weld Interface Temperature (WIT). Utilizing the Design of Experiments (DOE) approach, a Taguchi L27 Orthogonal Array (OA) was employed to evaluate the effects of five process parameters, which are rotational speed, friction pressure, friction time, forging pressure, and forging time on the three target properties. The results indicate that the optimal parameters for maximizing tensile strength are 1400 rpm rotational speed, 30 MPa friction pressure, 2 s friction time, 140 MPa forging pressure, and 2 s forging time. For achieving the maximum upset, the optimal parameters are 1700 rpm rotational speed, 50 MPa friction pressure, 3 s friction time, 120 MPa forging pressure, and 2 s forging time. To attain the optimal weld interface temperature, the optimal parameters are 1400 rpm rotational speed, 30 MPa friction pressure, 2 s friction time, 100 MPa forging pressure, and 2 s forging time. Pareto analysis revealed that forging time has the most significant influence on tensile strength while forging time and friction pressure have the most significant impact on upset. For weld interface temperature, forging time, friction pressure, and rotational speed were found to be the most influential factors. Confirmation tests conducted using the optimized parameters yielded results that closely matched the predicted values obtained from regression analysis. The error percentages for tensile strength, upset, and weld interface temperature were 0.45%, 6.36%, and 1.52%, respectively, demonstrating the validity of the optimized parameters. The findings of this study provide valuable insights into optimizing FW parameters for joining SS and EN3B, paving the way for the development of high-quality, lightweight, and high-performance components for various industries, including automobile and aerospace.