In-situ preparation of robust self-lubricating composite coating from thermally sprayed ceramic template

Abstract

The self-lubricating ceramic coatings that can control friction and wear have attracted researchers’ widespread attention. However, the poor interfacial bonding between lubricants and ceramics and the deterioration of mechanical properties due to a tribological design limit their practical applications. Here, a robust self-lubricating coating was fabricated by an in-situ synthesis of MoS2/C within inherent defects of thermally sprayed yttria-stabilized zirconia (YSZ) coatings. The edge-pinning by noncoherent endows hybrid coatings with excellent interfacial strength, increasing their hardness (HV) and cohesive strength. Furthermore, owing to the formation of a well-covered robust lubricating film at a frictional interface, a coefficient of friction (COF) can be reduced by 79.6% to 0.15, and a specific wear rate (W) drops from 1.36×10−3 to 6.27×10−7 mm3·N−1·m−1. Combining outstanding mechanical properties and tribological performance, the hybrid coating exhibits great application potential in controlling friction and wear. Importantly, this strategy of introducing the target materials into the inherent defects of the raw materials to improve the relevant properties opens new avenues for the design and preparation of composite materials.

Keywords

• self-lubricating ceramic coatings
• thermal spray
• in-situ synthesis
• mos2/c
• friction and wear
• mechanical properties