The microstructure and wear behavior of WC-reinforced diamond composite coating

Herein, diamond and diamond/WC composite coating were deposited on the surface of 45 steel by induction brazing. The microstructures of the composite coating were studied by scanning electron microscope, energy dispersive spectrometer, and X-ray diffractometer, and the wear resistance of the composite coating was assessed by rubber wheel abrasion test. The microstructure investigation indicates that both Cr3C2 and Cr7C3 carbides are formed at the interface between the diamond and BNi-2 alloy matrix, and Ni2W4C and NiW was formed at the interface between WC and BNi-2 alloy matrix. When WC is added to the diamond coating, the microhardness of the BNi-2 alloy matrix increases, and the microhardness of the BNi-2 alloy matrix reaches 583 HV0.2, which is 7.6% higher than that of the coating without WC. In addition, after 120 min wear test, the wear loss of the diamond WC composite coating is 0.337g, which is reduced by 31.5%. In the wear tests, abrasive wear was the main wear mechanism for composite coating. WC particles in diamond/WC composite coating improved the wear resistance and hardness of the alloy matrix.