The coefficient of friction of thermal sprayed ceramic coatings is high, and the introduction of traditional lubricants will cause the mechanical properties of the coatings to decline, which severely limits their application. Due to the excellent mechanical properties and high wear resistance of thermal spray ceramic coatings, the development of self-lubricating ceramic coatings with a long service life is critical to solving the problems of friction, wear and lubrication of mechanical parts under harsh working conditions.
The wear and surface engineering research group of Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences has long been devoted to the research on the technology and performance of thermal spray ceramic-based coatings. Recently, the research group prepared YSZ/Ag self-lubricating coating on 316L stainless steel substrate by thermal spraying technology, vacuum impregnation and in-situ synthesis. The study found that Ag particles were distributed in the pores and cracks of the YSZ coating, and the microhardness, fracture toughness and cohesive strength of defects were improved by filling Ag. In addition, due to the formation of a lubricating film during sliding in vacuum, the friction coefficient and wear rate of the coating are significantly reduced after the introduction of Ag. The friction coefficient of the YSZ/Ag coating is about 1/2 of the YSZ coating. The wear rate is about 1/600 of the YSZ coating. At the same time, the introduction of Ag lubricant greatly reduces the wear of the dual ball. Since the Ag lubricant can supplement and repair the formed lubricating film, the YSZ/Ag self-lubricating coating has a relatively long service life (>100,000 slip cycles).
The results of the recent study were published in Applied Surface Science, 2020, 518.