On selecting proper process parameters for cold metal transfer (CMT)–based wire arc additive manufacturing (WAAM) process

This paper addresses the selection of process parameters for the cold metal transfer (CMT)–based wire and arc additive manufacture (WAAM) process. Experimental tests were conducted using different wire feed and travel speeds with a Fronius-CMT welding source to produce single-weld beads using an H13 filler wire. Optimizing these two parameters enables the achievement of desired bead geometry, improved part quality, and reduced fabrication time and material consumption. Geometric characteristics of the weld bead, such as width, height, and contact angle, were measured using a scanning microscope and analyzed with PolyWorks software. The Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) was employed to determine the optimal process parameters considering heat input, height, width, and contact angle. The results revealed the strong influence of heat input on weld bead geometry. Increased heat input resulted in a greater width and height of the weld bead. However, the relationship between heat input and contact angle was more complex, with the contact angle significantly influenced by the applied power. Higher power values were associated with a decreased contact angle. The parameters were selected, thanks to the TOPSIS, and were used to fabricate an H13 part. Sound metallurgical bonding, absence of large defects, and expected geometries were obtained, validating the proposed method.