Application of high temperature solid lubricants for impregnation of P/M parts

摘要

Modern tribological systems are very often subjected to difficult operating conditions. The most complicated tribological process occurs in mating systems associated with mixed and boundary lubrication This especially concerns units used at elevated temperatures. Under such conditions, conventional methods of lubrication are much less effective;;new solutions are being sought. Recently, the direction of adaptation to lubricating agents consisting of nanoparticles of solid lubricants with a plate structure has arisen as an alter- tive concept [1, 2, 3]. The results of tribological and structural tests of solid lubricants are presented in this work. The work also includes the presentation of results of tests of solid lubricants subjected to an innovative method of mechanical delamination of materials. An effect of the delamination is the presence of nanostructured flakes. Materials of this type exhibit significantly better tribological properties [2, 4]. Tribological tests were conducted on T-10 and T-21 testers (Institute for Sustainable Technologies - National Research Institute, ITeE-PIB in Radom). Testing was performed on MoS2, WS2, h-BN, BaF2, CaF2, and a mixture of MoS2 with an addition of graphite and WS2 with an addition of graphite. The process of micromechanical delamination of lubricants was carried out with a powder burnishing tool (NP-1). SEM tests were performed using an PEI-INSPECT-S microscope with an EDSEDAX attachment, located at the Metal Forming Institute (INOP) in Poznan. The results obtained showed that nanoparticles of solid lubricants - MoS2, WS2, MoS2 with the addition of graphite, and WS2 with the addition of graphite - are materials that will find applications in the modification of the surface layers of parts used for components working in difficult usage conditions. The use of this type of lubricant allows for decreasing the friction coefficient and achieving a value below 0.1, which directly effects a 2-3-time increase in the durability of components cooperating as friction pairs. The obtained graphene-like sulphide nanoparticles of solid lubricants and mixtures with graphite are characterized by a low coefficient of friction, good endurance under heavy loads, high mechanical and chemical stability, and high resistance to wear [3, 4].