Research of Laser Cladding on Mold Copper

Abstract—Adopting laser cladding technology, 3 kinds of alloy powder (Ni, Fe, Co) is successfully cladded on the surface of mold copper plate. Metallurgical bonding between cladding layer and Cu substrate is generated. Cladding layer has fine grained structure without micro-crack and bubble. The average hardness of Ni-based cladding layer is 672.3HV0.5, which is 6.5 times of the average hardness of Cu substrate. The major constituent phases of Ni-based cladding layer are γ-Ni austenite phase, CrB compound phase, M7C3 and M23C6 carbonization phase, and Ni3Si phase. The average hardness Fe-based cladding layer is 502.5 HV0.5, which is about 5.5 times of the average hardness of Cu substrate. Co-based cladding layer has higher hardness than Ni-based and Fe-based. The average hardness Co-based cladding layer is 810 HV0.5, which is about 7.2 times of the average hardness of Cu substrate. The main composition of cladding layer is Co, Cr and a bit of Ni, Fe, W. The major constituent phases of cladding layer are γ-Co austenite phase, (Fe, Ni) solid solution phase, CrCo compound phase, CoCx and Cr7C3 carbonization phase, and Mn3Co7 phase