The Preparation And Tribological Properties Of Anti-friction And Anti-wear Lubricant Additives

Lubricant additives are widely used in the field of friction lubrication because of the advantages to reduce the friction coefficient and wear rate and repair the damages on the wear surface.The most commonly used of the additives is the anti-friction and anti-wear lubricating oil additives.With the development of extreme pressure anti-friction and anti-friction additives,the quality of lubricating oil will be greatly improved.Although conventional sulfur,phosphorus,chlorine and other active elements of additives still occupy an irreplaceable position for a long period of time,these active elements will cause great environmental pollution and difficult to meet the environmental requirements.Therefore,the research and development of new and environmentally friendly lubricating oil additives,especially N-containing heterocyclic borate esters,ionic liquids and micro-nanoparticles,have been widely concerned by many domestic and foreign researchers.In this paper,organic N-containing heterocyclic borate eaters and tetrafluoroborate ionic liquid were prepared by molecular design.The Cu microparticles and SiO2 nanoparticles were also prepared.The tribological performance of the Cu micropaticles and N-containing borate esters or the ionic liquid were studied in detail.In addition,the polytetrafluoroethylene particles which filled with Cu microparticles or Si02 nanoparticles were prepared and their tribological properties in base oil were also discussed.Finally,this paper mainly analyzes the wear surface that lubricated with different lubricant additives by X-ray photoelectron spectroscopy(XPS),to explore the lubrication mechanisms of the lubricant additives.This article main research contents are as follows:(1)The preparation and tribological properties of organic N-containing heterocyclic borate esters and Cu microparticles.Four kinds of organic N-containing heterocyclic borate eaters BNH and Cu microparticles were synthesized in this paper.The tribological properties of the lubricant additives in base oil were studied on the MR-S10B four-ball friction and wear tester.Scanning electron microscopy(SEM),(EDS)and XPS were carried out to analysis the worn surfaces on the steel ball.The results show that the four kinds of N-containing heterocyclic borate esters and Cu microparticles can improve the anti-friction and anti-wear properties of the lubricant oil and there is a complex interrelationships effect between them.The main lubrication mechanism is the formation of the friction chemical reaction film that consist of B2O3,Fe2O3,Fe3O4,organic nitrogen compounds on the worn surfaces.(2)Preparation and tribological properties of ionic liquid and Cu microparticlesThe functionalized tetrafluoroborate ionic liquid[EAMIM]BF4 was prepared by simple substitution reaction.The tribological properties of the ionic liquid and Cu microparticles in sunflower seed oil were studied by the four-ball friction and wear tester.The chemical components of the worn surface was analyzed by XPS and the lubricating mechanisms were also analyzed.The results show that both the ionic liquid and Cu microparticles have the good anti-friction and anti-wear effect and the synergistic effect was existed between them.XPS analysis results show that the additives can react with the metal to generate a friction chemical reaction film that consist of Cu,CuO,Fe2O3,Fe3O4,Fe2B and FeF3,and the self-repairing ability of Cu microparticles also can improve the tribological properties of base oil.(3)Preparation and tribological properties of the filled polytetrafluoroethylene(PTFE)The P VP-protected Cu microparticles and SiO2 nanoparticles were prepared by pre-reduction oxidation method and precipitation method respectively.The tribological performance of the PTFE particles and the PTFE particles filled with Cu microparticles or SiO2 nanoparticles by the four-ball friction and wear machine.It was found that tribological properties of the filled PTFE particles is better than that of the PTFE particles and the XPS analysis of the wear surface showed that the lubricating mechanisms are the transfer film of the self-lubricating of PTFE and the friction chemical reaction film of silicon oxide.In addition,the self-repairing ability of Cu microparticles is also contribute to the improvement of tribological properties of base oil.