Dual interfacial characterization and property in multi-material selective laser melting of 316L stainless steel and C52400 copper alloy

Abstract Manufacturing multi-material part is one of the native advantages of selective laser melting (SLM) due to its layer-by-layer manufacturing method, which is attracting more and more attention in recent years. In an effort to reveal the dual interfacial characterization of dissimilar materials manufactured by SLM with different printing sequences, this paper presents the morphology, microstructure, element distribution, phase composition and microhardness of multi-material interfaces between SLMed 316L steel and C52400 copper alloy. Both interfaces display isolated alloy islands with various shapes and different morphologies. The melt pool at 316L/C52400 interface is deeper and narrower than that at C52400/316L interface. Small 316L and C52400 spheres with a size of 1–5 μm are formed under the surface tension, Marangoni convection in the melt pool and rapid cooling condition, in which many smaller particles with a size of