GREY-BASED TAGUCHI METHOD FOR OPTIMIZATION OF BEAD GEOMETRY IN LASER BEAD-ON-PLATE WELDING

This study focused on the bead on plate welding of super austenitic stainless steel sheets using laser welding. Taguchi Technique is applied to plan and conduct the experiments. The output variables such as Bead Width (BW), Depth of Penetration (DP) and Aspect Ratio (AR) were measured from the bead on plate weld. These output variables were determined according to beam power, travel speed and focal position. The bead on plate welding was performed on two different shielding gases like argon and helium. The shielding gas affects the weld bead characteristics such as shape, penetrationwelding efficiency etc. It is appropriate to apply Taguchi’s technique to a complex system like welding process. Therefore, this study is made to determine the near optimal welding process parameters (beam power, travel speed and focal position) using grey relational analysis by simultaneously considering multiple output parameters (bead width, depth of penetration and aspect ratio). Taguchi experimental design for determining welding parameters was successful. The gray relational grade helped to quantify the integrated performance of bead on plate welding of laser beam welding process. Confirmation experiment has been conducted to validate the optimized parameters. The predicted and initial parameters have the better aspect ratio. The optimal welding conditions were identified in order to increase the productivity and minimize the total operating cost. The process input parameters effect was determined under the optimal welding combinations.