Resistance Spot Welding Process Optimization Using Taguchi Robust Method for Joining Dissimilar Material

Abstract

Steel sheet joining were dominantly by resistance spot welding (RSW) method. It is the most implemented in automotive mass production in which the heat is applied to the materials. Joining different material with different properties is a challenge. Thicker material needs more current and time. Meanwhile, the thinner material may burn and weaken if the excessive parameters apply. The purpose of this study is to identify the optimum spot weld parameters for joining dissimilar materials with different thickness that involve high tensile strength steel and low carbon steel in the automotive application. In this study, weld parameters with varying electrode forces, welding currents, and welding times are analyzed by applying a Taguchi robust method for the design of experiment (DOE). The L9 orthogonal array has been chosen due to the particular material specimen and time constraint. In the analysis, the higher value of signal-to-noise (S/N) ratio indicates the good responses of testing parameter when the level changed. Base of the plotted S/N ratio graph for each factor, Taguchi robust method has suggested that A3 (5000V), B3 (25 cycle), and C2 (150N) as the optimum weld parameters. The confirmation test afterward, finally proved that the Taguchi robust method was a liable DOE method and has been successfully optimized the spot weld parameters.