OPTIMIZATION OF LASER TEXTURING PROCESS PARAMETERS TO MAXIMIZE THE ULTIMATE TENSILE STRENGTH OF LASER TEXTURED AZ31B MAGNESIUM ALLOY JOINTS MADE BY COLD METAL TRANSFER WELDING USING RESPONSE SURFACE METHODOLOGY

摘要

In this work, a mathematical relationship has been formulated between laser texturing process variables and the Ultimate Tensile Strength (UTS) of the AZ3 1B Mg alloy joints made by Cold Metal Transfer welding (CMTW) process. The nominal depth (D), diameter (?) and separation distance (SD) were the input parameters and three-factor and two-level central composite design (CCD) was applied to build up the experimental design matrix. By fixing the already optimized parameters of CMTW viz: current intensity 60A, Welding Speed 6 mm/sec, Gas flow rate 14 L/min and Nozzle to Plate Distance 6 mm and with the experimental matrix using laser texturing process variables, twenty joints were produced using CMTW process. The UTS was measured by standard ASTM procedure. The ANOVA was performed to find out the most significant main and interaction parameters and empirical relationship was determined. The laser texturing process (LST) variables were optimized by making response graphs and contour plots using Minitab software. The formulated mathematical relationship would be useful to forecast the UTS of CMT welded AZ3 1B joints for stipulated confidence limit. The contour plots will be helpful to acquire the optimal conditions of LST process variables.