Parameter Optimization Using Multi-objective Taguchi Method and Response Surface Methodology for the Laser Welding of Dissimilar Materials
J-Q. Long, W-H. Huang, J-W. Xiang and J-X. Zhou
In order to improve the quality of the dissimilar materials weld joints, the optimization of laser welding process parameters, such as laser power, welding speed and beam angle, are carried out. A three-dimensional (3-D) finite element method (FEM) model is employed to simulate the steel to Al-alloy laser welding process. The FEM simulations are carried out using commercial FEM software SYSWELD, which takes into account thermal, metallurgical and mechanical aspects. This paper presents an application of multi-objective Taguchi method attempts to consider simultaneously the multiple quality characteristics, namely weld bead distortion and von Mises stress. The Taguchi method with L9 orthogonal array is used to perform the numerical experiment design. The optimal welding parameter for multi-objectives is obtained using multi signal-to-noise ratio and total normalized quality loss. The significant level of the welding parameters is further analysed using analysis of variance (ANOVA); furthermore, the method of response surface methodology (RSM) is used for regression modelling to establish the relationship between the laser welding input parameters like laser power, welding speed and beam angle and for optimizing the process parameters. Based on the numerical experiment confirmation test, the results show that the proposed method can be effectively applied to estimate the weld bead distortion and von Mises stress which can improve the quality of the dissimilar materials weld joints.
Keywords: Laser welding, Al-Mg-Si alloy, DC04 steel, finite element method (FEM), multi-objective Taguchi method, response surface methodology (RSM), dissimilar materials