超音速火焰喷涂WC-12Co、WC-10Co4Cr和Cr3C2-25NiCr涂层在不同介质中摩擦行为研究

Friction Behavior of WC-12Co、WC-10Co4Cr and Cr3C2-25NiCr coatings under different media*

摘要:

为了研究硬面涂层在不同介质中的摩擦行为，以WC-12Co、WC-10Co4Cr和Cr3C2-25NiCr硬面材料为原料，采用超音速火焰喷涂制备得到了三种不同成分的硬面涂层。通过显微硬度计、摩擦磨损仪和扫描电镜等对涂层性能分析，结果表明，涂层中的孔隙率和粘结相的含量密切相关，当粘结相含量为12wt.%（Co）时，其孔隙度为1.11%；粘结相含量为14wt.%（CoCr）时，其孔隙度为0.98%；粘结相含量为25wt.%（NiCr）时，其孔隙度降低为0.92%。空气中，WC-10Co4Cr的硬度最高，其摩擦系数最小；Cr3C2-25NiCr的硬度最小，其摩擦系数最大。1mol/L HCl的环境中，NiCr的耐腐蚀性能最好，使Cr3C2-25NiCr涂层的摩擦系数稳定；而纯Co和CoCr的耐腐蚀性能较差，使WC-10Co4Cr和WC-12Co涂层的摩擦系数呈现出波浪状的变化规律。1mol/L NaOH的环境的摩擦过程中，硬质相的腐蚀会使涂层表面的硬度下降，使摩擦系数增加。

Abstract:

In order to study the friction behavior of hard surface coatings under different media, the coatings were prepared by HVOF with WC-12Co, WC-10Co4Cr and Cr3C2-25NiCr materials as raw materials. The properties of the coatings were analyzed by micro-hardness tester, wear tester, scanning electron microscope and so on. The results showed that the porosity of the coating was closely related to the content of the binder phase. In air, WC-10Co4Cr had the highest hardness and the lowest friction coefficient, while Cr3C2-25NiCr had the lowest hardness and the highest friction coefficient. In the environment of 1mol/L HCl, the best corrosion resistance of NiCr binder made the friction coefficient of Cr3C2-25NiCr coating stable, and the poor corrosion resistance of pure Co and CoCr made the friction coefficient of WC-10Co4Cr and WC-12Co coatings with high and low fluctuations. In the friction process under 1mol/L NaOH environment, the corrosion of hard phase could reduce the hardness and increase the friction coefficient.