Microstructure and properties of laser cladding diamond-metal wear-resistant coating

Abstract

The surface of 10 to 30 μm fine-grained diamond was plated with Cr, and the Cr- plated diamond was then mixed with Ni-Cr-B-Si powder and placed on the surface of carbon steel. A wear-resistant coating was prepared by melting the preset powder on the carbon steel surface using a laser heat source. The results show that the thickened Cr coating on the diamond surface can effectively protect the diamond in the laser high-temperature thermal field, which prenvents oxidation and graphitization of the diamond at high temperatures and achieves a metallurgical bond between the diamond and the metal matrix. The metallography, phase and morphology of the coating are analyzed. It is found that the diamond could significantly improve the cooling rate of the coating, refine the condensing structure, increase hardness, and enhance the wear resistance of the coating. The wear resistance of the cladding coating, with a mass fraction of 20% Cr-plated diamond, is 4.6 times higher than that of the coating without diamond. Additionally, the corresponding friction coefficient is nearly 50% lower.

Keywords

• diamond
• surface metallization
• wear-resistant coating
• laser cladding