The Study On Preparation And Tribological Properties Of GO/MoS₂ Lithium Complex Grease

Friction wear is one of the main causes of material damage and energy consumption,so it is very important to control friction wear to save energy and extend the working life of the machine.The lubricating oil?grease?can effectively reduce the friction,various additives are usually added to the lubricating oil?grease?to improve the lubricating property of the lubricating oil?grease?.With the development of nanotechnology,it has been found that the addition of a certain concentration of nanoparticles to lubricating oil?grease?can effectively improve it's lubricating properties.At present,there are many researches on the antifriction and antiwear properties of nanoparticles added to lubricating oils,but there are few studies on the dispersion stability in lubricating oils.Among them,many kinds of nanoparticles are studied as grease additives,and some achievements have been made.However,there are relatively few studies on compounding nano-additives.Due to the synergy between the various nanoparticles,the compound nanoparticles have an excellent lubricating effect as an additive to the grease.The work was based on the laboratory-designed ultrasound-assisted ball milling and microwave-assisted ball milling test equipment,the GO lubricant oil was obtained by dispersing the GO in the base oil PAO6 using different dispersion methods?surface modification and dispersion,dispersanting agent dispersion,surface modification?.The GO before and after modification were characterized by scanning electron microscopy?SEM?,X-ray diffraction?XRD?and transmission electron microscopy?TEM?etc.The effectiveness of surface modification and the mechanism of stable dispersion The dispersion stability of the GO in the base oil was measured by ultraviolet–visible spectrophotometer?UV-VIS?and Zeta potential,the effectiveness of surface modification and stable dispersion mechanism were discussed separately.The results indicated that the stability of GO treated by surface modification and dispersant dispersion treatment is 44.8%and 35.5%higher than single surface modification dispersion or dispersant dispersion method.In this experiment,the GO/MoS₂ lithium complex grease was prepared by using the reaction kettle.The friction performance of the composite lithium-based grease of GO/MoS₂ at different concentrations and ratios was tested by a four-ball friction tester.The friction of the grinding ball was performed by a metallographic microscope.The surface was observed and the mechanism of friction reduction was discussed and analyzed.The results show that the addition of GO and MoS₂ can effectively improve the friction performance of the composite lithium-based grease,and the optimum concentration of the additive is 0.1 wt%,the ratio is GO:MoS₂=50 wt%:50 wt%,and the wear spot diameter was reduced by 24%,the average friction coefficient was reduced by 45%,and the average friction was reduced by 46%.The two nanoparticles are compounded into the lithium complex grease,and the antifriction performance is significantly improved.Due to the small size effect and extremely thin laminated structure,which enable the particles to easily enter the contact area and fill into the scratch on the surface,reduce the roughness of the contact surface and acts as a self-repairing effect;and the spherical nanoparticles with higher hardness play a role of micro-bearing on the surface of the friction pair,which reduces the friction coefficient and improves the friction-reducing effect of the grease.