Application of L6 Orthogonal Array for Optimal Selection of Some Process Parameters in GMAW Process

Desired performance of Gas Metal Arc Welding (GMAW) needs optimum selection of process parameters. A multi-response optimization problem has been formulated in this work in search of an optimal parametric combination to obtain a favourable butt joint by GMAW process using C02 gas shield. Taguchi's L6 orthogonal array design, and the concept of signal-to-noise ratio have been used to derive an objective function to be optimized within the experimental domain. All experimental runs have been repeated twice to check repeatability. The welding performance has been assessed through measurement of microhardness of the weld bead, and ultimate tensile strength of the weldment. The significance of factors on overall output features of the weldment has been evaluated quantitatively by ANOVA which shows that welding voltage has the maximum influence to obtain a sound weld within the range of experimental parameters considered.