Multi-criteria decision-making-based optimization of CMT-WAAM process parameters for SKD61 steel coating

This study investigates the optimization of process parameters for coating SKD61 tool steel using the Cold Metal Transfer-based Wire Arc Additive Manufacturing (CMT-WAAM) technique for component repair applications. Welding current (I) and travel speed (v) were varied to analyze their influence on bead geometry and energy efficiency. Three multi-criteria decision-making (MCDM) methods – i.e. TOPSIS, VIKOR, and GRA – were applied to identify the optimal settings. The results indicate that the parameter combination I = 140 A and v = 0.4 m/min yields the best balance between coating quality and efficiency, achieving bead width (W) = 8.23 mm, height (H) = 2.18 mm, penetration (p) = 2.03 mm, dilution (d%) = 31.38%, deposition shape coefficient (kd) = 0.695, and Volumetric Energy Cost (VEC) = 43.08 J/mm³. These findings provide a reliable basis for efficient process control and parameter selection in CMT-WAAM repair of SKD61 tool steel components.