Sealing Performance of Different Materials and Seal Products on Electroplated Chrome and High-Velocity Oxy-Fuel-Sprayed WC-10Co-4Cr Coatings

This study first assessed the friction and wear properties of two polytetrafluoroethylene materials sliding against electroplated chrome and high-velocity oxy-fuel-sprayed WC-10Co-4Cr coatings. Subsequently, the sealing performance of three different structure seals made from these two polytetrafluoroethylene materials was investigated on both electroplated chrome and high-velocity oxy-fuel-sprayed WC-10Co-4Cr coatings. The study results indicate the following: in terms of changes in the counter-face surface roughness, both the electroplated chrome and high-velocity oxy-fuel-sprayed WC-10Co-4Cr surfaces exhibited an increase in surface roughness after sliding, demonstrating the phenomenon of “soft material wearing hard material.” Moreover, the changes in surface roughness were greater after sliding against wollastonite mineral-filled polytetrafluoroethylene than against polyether ether ketone-filled polytetrafluoroethylene, indicating that wollastonite mineral-filled polytetrafluoroethylene was more likely to cause damage to the metal surface. Regarding the friction coefficient and wear amount, under dry friction conditions, both materials exhibited higher friction coefficients but lower wear rates on high-velocity oxy-fuel-sprayed WC-10Co-4Cr surfaces, while showing lower friction coefficients but higher wear rates on electroplated chrome surfaces. This behavior was related to the ease of transfer film formation and the stability of the transfer films formed by polytetrafluoroethylene materials on the two surfaces. In terms of the products’ sealing performance, test results showed that, for composite seals with polytetrafluoroethylene as the counter-face, sealing performance was better on high-velocity oxy-fuel-sprayed WC-10Co-4Cr surfaces than on electroplated chrome surfaces. For seals with rubber as the counter-face, there was little difference in sealing performance between high-velocity oxy-fuel-sprayed WC-10Co-4Cr and electroplated chrome surfaces.