Effect of MoS2/PTFE coatings on performance of Si3N4/TiC ceramics in dry sliding against WC/Co

To enhance the tribological performance of Si3N4/TiC ceramics, MoS2/PTFE composite coatings were deposited on the ceramic substrate through spraying method. The micrographs and basic properties of the MoS2/PTFE coated samples were investigated. Dry sliding friction experiments against WC/Co ball were performed with the coated ceramics and traditional ones. These results showed that the composite coatings could significantly reduce the friction coefficient of ceramics, and protect the substrate from adhesion wear. The primary tribological mechanisms of the coated ceramics were abrasive wear, coating spalling and delamination, and the tribological property was transited from slight wear to serious wear with the increase of load because of the lower surface hardness and shear strength. The possible mechanisms for the effects of MoS2/PTFE composite coatings on the friction performance of ceramics were discussed.

Automated summary

The study demonstrated that MoS2/PTFE composite coatings can effectively reduce the friction coefficient of ceramics, resist adhesion wear, and the primary tribological mechanisms include abrasive wear, coating spalling and delamination. With the increase of load, the friction performance tends to deteriorate due to lower surface hardness and shear strength.