Microstructure evolution in steel/copper graded deposition prepared using wire arc additive manufacturing

Fabrication of steel and copper bimetallic material through cold metal transfer-based wire arc additive manufacturing (CMT-WAAM) is a novel exploration. In this experiment, a graded structure was obtained successfully by depositing copper layers on the AISI 316L stainless steel. The iron-rich phases were present in the deposit up to the interface of second and third copper layer, and the iron distribution in the copper matrix was comparably more uniform after the first copper layer. The iron phase is deposited in globular and dendritic morphologies. Supersaturated copper phase precipitates were traced inside the globular iron, but no such precipitation was evident in iron dendrites. No metastable or intermetallic phases were detected by XRD analysis. Hardness measurement results were in good agreement with the grain size and phase precipitation within the copper layers.