中国科学院材料磨损与防护重点实验室/先进润滑与防护材料研究发展中心知识库

The properties of the working surfaces are linked to the safety and lifespan of the modern machines so that variety of coatings are used to protect the parts from breakdown. The NiCoCrAlYTa coating, which has an excellent oxidation resistance, usually undergoes more serious friction and wear due to its lower micro-hardness in contrast to the ceramic coatings. Therefore, the composite coatings reinforced by WC-Co are prepared by HVOF sprayed technology and are also characterized by scanning electron microscope, Raman spectrometer and X-ray diffraction. At the same time, the friction and wear behaviors as well as the mechanisms of different friction pairs are also discussed, in detail. The composite coatings, which mainly consist of γ-(Ni, Co), β-NiAl, γ’-Ni₃Al, WC and W₂C, are dense and uniform. With the increase of WC-17Co, the microhardness of NiCoCrAlYTa/WC-Co composite coating has enhanced from 641.4 HV_300g to 859.7 HV_300g. The wear rates of the composite coatings (10^-5-10^-6 mm³·N^-1m^-1) are far lower than those of the as-sprayed NiCoCrAlYTa coating (10^-4 mm³N^-1m^-1). Overall, the mechanical properties and tribological behaviors of the coatings are greatly improved with the addition of WC-Co.