Self-lubricating ceramic coatings with high reliability and long service life are very important to solve the friction, wear and lubrication problems of the mechanical components serving in extreme harsh conditions. However, traditional self-lubricating ceramic coatings have high brittleness, and their mechanical properties would be further degraded because of tribological design, which significantly reduces their service stability and crack resistance. Herein, several kinds of solid lubricants have been in-situ synthesized in the inherent pores and microcracks of thermally sprayed ceramic coatings. Thermally sprayed ceramic coatings with excellent mechanical properties and outstanding tribological performance can be further developed. The morphology, phase composition, element distribution and structure of worn surface have been analyzed to clarify the formation mechanism and evolution of the lubrication films, thus revealing the mechanisms of lubrication and failure of the coatings. The influencing rule and mechanism of the types, contents, sizes and growth patterns of lubricants on the mechanical properties as well as friction and wear properties have been investigated and the new principle of lubrication and anti-wear as well as the new method of controlling friction and wear were put forward. Based on the above studies, the relationship and mechanism among in-situ synthesized lubricants, mechanical properties, lubrication performance and wear life of the coatings have been revealed, which provided a new idea for the design and preparation of thermally sprayed self-lubricating ceramic coatings.

Coating; Thermal spraying; In-situ synthesis; Tribological properties; Lubrication mechanism