Interfacial Phenomena and Microstructure of Copper/Steel Bimetal Structure Produced by a New Hybrid Additive Manufacturing Process Combining Selective Laser Melting and Directed Energy Deposition

As a novel exploration, the hybrid additive manufacturing (AM) process combining selective laser melting (SLM) and directed energy deposition (DED) was used to produce a copper/steel bimetal structure in this paper. Stainless steel was deposited on the SLMed Cu-Cr alloy substrate successfully by DED. The interfacial phenomena, microstructure, and forming mechanism were investigated systematically. The Cu element of the substrate flowed up due to the Marangoni flow, and liquid phase separation occurred during the process. This work indicates that the microstructure and morphology between the cladding layer of steel and Cu-Cr substrate are significantly influenced by the laser power.