Study On The Tribological Properties Of Nano LaF₃ And Serpentine Lubricating Oil Additive

The normal operation of marine machinery and equipment can not do without lubricating oil.The performance of lubricating oil directly affects the service life of equipment.With the development of nanotechnology,more and more researches focus on nanoparticles as lubricant additives.This paper selects nano rare earth compound LaF₃ and serpentine silicate as lubricating oil additives added to base oil,evaluates its tribological properties by friction and wear test for nano LaF₃ and serpentine used as lubricating oil additives and provides a theoretical basis for its practical application.The main research contents and results are as follows:?1?LaF₃ nanoparticles were prepared by method combined chemical precipitation method and physical ball milling method.The nano serpentine was prepared by omnidirectional planetary ball mill.The particle size of nano LaF₃ and nano serpentine was characterized by laser particle size analyzer.Nano LaF₃ and serpentine phase composition was characterized by using X-ray diffractometer.?2?The modification effect of Span-80,Tween-80,peregal OS-15 three kinds of surfactants on the nano LaF₃ and serpentine was compared.Their transmittance and absorbance were evaluated by visible spectrophotometer.The results found that peregal OS-15 is the best modifier.The reason is that the ether group has good adsorption effect on nanoparticles,forming steric hindrance stabilization mechanism.?3?The paper designs orthogonal test with three factors and five levels.The friction coefficient and wear scar diameter two results were evaluated by four ball friction wear test.The experimental results optimize the parameters of anti-wear and friction reducing performance:nano LaF₃ and serpentine total amount was 0.6%,nano LaF₃ and serpentine added proportion is 3:1,total nanoparticles and peregal OS-15 added proportion is 2:1.Compared with the base oil,the friction coefficient of lubricating oil with nano LaF₃ and serpentine is reduced by 43.0%,the wear scar diameter decreased by 38.8%.?4?Antiwear and antifriction properties of base oil and nano additive lubricating oil were compared by reciprocating friction and wear tester.It was found that the friction coefficient and wear rate of nano additive lubricating oil samples are better than that of base oil samples.The test cylinder sleeve samples were observed in metallurgical microscope and SEM,the results show that the basic oil sample was wear-out and there are many scratches on the friction surface.Energy spectrum scanning showed that there are four elements on the surface of nano additive lubricating oil sample:F,La,Si,Mg.The possible mechanism of friction reduction and anti-wear of nano LaF₃ and serpentine is that the nano particles enter into the friction pair during the friction and wear process,repair and fill the scratch caused by friction in time to play the antiwear and antifriction effect.