TRI-OBJECTIVE OPTIMIZATION OF CARBON STEEL SPOT-WELDED JOINTS

The investigation was intended to optimize tri-objective of the welding parameters on tensile-shear (TS) strength, Fusion Zone (FZ) size and Heat Affected Zone (HAZ) size development in resistance spot welding (RSW) process of similar sheet metals joint. The experimental studies were conducted on varying weld time, electrode force and weld current for 1.2mm thickness of low carbon steel. The experimental tests, conducted according to the settings of process parameters were carried out according the L9 Taguchi orthogonal array in randomized way. The optimum process parameter for triobjective was obtained using multi signal to noise ratio (MSNR) and further analyzed the significant level using analysis of variance (ANOVA). Response Surface Method (RSM) was employed to developed second order model at optimal welding parameters. The confirmation tests results demonstrate that the tri-objective Taguchi method used to optimize the welding parameters and enhance the welding performance is practical and effective in RSW process.