Investigations and Multi-response Optimization of Process Parameters for SS316L Cold Metal Transfer-Wire Arc Additive Manufactured Samples

Wire and arc additive manufacturing (WAAM) utilizes an electric arc as the primary heat source and solid wire as the material feedstock. Despite potential limitations in precision compared to powder-bed systems, WAAM boasts remarkable deposition rates. This characteristic enables the rapid manufacture of large metallic structural parts, making WAAM a preferred choice for academic research and industrial applications. This study explores the impact of three input process parameters-current (I), welding speed (WS), and Contact Tip to Work Distance (CTWD)-each at three varying levels on three key mechanical properties of SS316L austenitic stainless steel fabricated samples. Through experimentation and analysis, the study evaluates three crucial mechanical properties: ultimate tensile strength (UTS), microhardness (MH), and residual stress (RS). The investigation uses Taguchi's Gray Relational Analysis method, employing an L9 orthogonal array design. Analysis of Variance (ANOVA) has been utilized to assess the impact of parameters on gray relational grade (GRG). The ANOVA analysis for the gray relational grade across various responses indicates that the current is the most significant factor, followed by welding speed and contact tip-to-work distance (CTWD). The contributions of current, welding speed, and CTWD are 76%, 21%, and 3%, respectively. The findings from Gray Relational Analysis (GRA) highlight that optimal performance in terms of maximum UTS, MH, and RS is achieved when employing specific parameter configurations: a I (110 A), WS (0.7 m/min), and CTWD of (3 mm).