Research on Laser-Hybrid Cladding of Ni-Cr Alloy on Copper

Abstract

In order to improve the wear resistance of the surface of thick copperplate, A layer of Ni-Co-Cr alloy on thick copperplate surface is performed by laser –hybrid cladding process. In laser cladding processing, it is known that it is difficult to get good metallurgical bonding between the layer and copperplate. Micro-arc deposition technology is developed to get a thin alloy layer on the surface of thick copperplate, and then using laser cladding method to make thick coating. Micro organization analysis and wear resistance comparison experiments are taken to the specimen. From the microscopic structure analysis, it can be seen that the deposition and substrate form favorable metallurgy bonding, as a narrow metallurgical bonding zone, about 20μm in width. The micro- structure photos show that the coating is more compact, and crystal grains are refined grain composed of γ-Ni, Cr7C3 and CrB. The micro-hardness of the cladding zone is between 650HV~850HV, which is much higher than the copper substrate. Roughness measurement of the specimens shows that the cladding layer is smoother. The experiment’s result shows that laser-arc hybrid cladding can perform coating of Ni-Cr alloy, metallurgy bonding with the copperplate, on its surface.