Microstructure and mechanical properties of CuSn/18Ni300 bimetallic porous structures manufactured by selective laser melting

This article presents a method for manufacturing CuSn/18Ni300 bimetallic porous structure, and it mainly aims to discover microstructure and mechanical properties of CuSn/18Ni300 bimetallic porous structure. The microstructure, bonding strength and fracture morphology of CuSn/18Ni300 bimetallic parts manufactured by selective laser melting were examined by X-ray diffraction, tensile test and scanning electron microscopy, respectively. Compression behavior and energy absorption behavior were investigated by compression tests. Analyses of microstructure show that CuSn/18Ni300 specimen consists of α-Fe phase, α-Fe/α-Cu mixed area and α-Cu phase. Microhardness at the interface of CuSn/18Ni300 bimetallic porous structure decreases from 18Ni300 part to CuSn part. The bonding strength of CuSn/18Ni300 specimen is 144.1 ± 41.59 MPa, which is much lower than the tensile strength of CuSn specimen. Additionally, we demonstrate that the compression behavior of CuSn/18Ni300 bimetallic porous structure can be subdivided into five stages, including the first linear elasticity, the first collapse plateau, the second linear elasticity, the second collapse plateau and the end densification. The energy absorption of CuSn/18Ni300 porous structure is higher than that of CuSn porous structure, and energy absorption increases as the porosity decreases. These findings provide a solution for optimizing the compression behavior and energy absorption of porous structure.