Optimization and Modeling of Process Parameters in Projection Welding Process using Multi-objective Taguchi method and RSM

Projection welding is a process that is being in industry for sheet and nut joining purpose especially in Automobile and Aerospace industries. This paper presents an alternative method to optimize process parameter of projection welding (PW) towards weld zone development. The optimization approach attempts to consider multiple quality characteristics, namely torque and heat affected zone (HAZ), using multi-objective Taguchi method (MTM). Also this paper presents and experimental investigation for optimization of torsional strength and HAZ of low carbon mild steel by using Taguchi method. The experimental study was conducted for plate thickness 1mm and M6 SQ nut under different electrode pressure, welding current and weld time. The optimum welding parameters were investigated using the Taguchi method with L9 orthogonal array. The optimum value was analyzed by means of multi-objective method, which involved the calculation of total quality normalized loss (TNQL) and multi single to noise ratio (MSNR). Significant level of the welding parameter was further obtained by using analysis of variance (ANOVA). Additionally, the first order model of predicting the weld quality zone development is derived by response surface methodology (RSM). The experimental results confirmed the validity of used Taguchi method for enhancing welding performance and optimizing the welding parameters in projection welding process. The confirmation test indicates that it is possible to increase torque and smaller HAZ significantly.