Investigation Of The Thermal Conductivity Of Carbon Materials Additives With High Thermal Conductivity In Silicone Oil

The wear and tear of equipment usually happen in industrial production.The reason is that the friction heat increases the temperature of the friction pair continuously,resulting in the lubricant failure and mechanical wear,and even shortening the lifetime of the equipment.To solve the problem,the thermal conductivity additive can be added into the base oil to enhance the thermal conductivity of the lubricating material and thus protect the friction pair.The research in the past decades showed that carbon materials are one of the most promising thermally conductive additives,including carbon nanotubes(CNTs),graphene nanosheets(GNP),and graphite powder(GP).Silicone oil is one kind of base oil with good heat resistance and widely used in the high-temperature condition.Therefore,this paper focus on investigating the thermal conductivity of carbon materials as an additive in dimethyl silicone oil.This article mainly explores thermal conductive lubricating materials from the views of physics and chemistry.The size of particles is optimized to form a more uniform and stable dispersion using ball-milling method.The carbon nanomaterials additives with high thermal conductivity are fabricated using chemical methods,which can reduce phonon scattering and interface thermal resistance effects.The thermally conductive lubricating materials is investigated by Maxwell-Garnett(M-G)thermal conductivity model,and COMSOL software simulates the application of it in heat-dissipating components.To enhance the thermal conductivity of lubricating materials,this paper finally summarizes the exploration method and application evaluation.The results show that:1.Graphite powder,carbon nanotubes and graphene nanosheet-dimethyl silicone oil thermally conductive lubricating materials were prepared by the ball-milling method.Compared with the thermally conductive lubricating materials prepared by the hybrid method,the thermal conductivity is improved,among of them,incorporation of graphene nanosheet additives into silicone oil,the thermal conductivity has been greatly enhanced.2.The thermal conductive additives are prepared using chemical method:(1)enhancing the phonon matching,the 3-aminopropyltriethoxysilane(APSi)which it has Si-O bond same as dimethyl silicone oil is amide grafted by carbon nanotube,to prepare CNTs-APSi thermal conductivity additive,and GNP-APSi is prepared with the same method.(2)the method of chemical binding force,the carbon hydroxyl silicone oil(2140)which has the molecular chain structure like the dimethyl silicone oil and containing hydroxyl groups at the beginning,is esterifying grafted by carbon nanotube,to prepare CNTs-2140 thermal conductivity additive,and GNP-2140 is prepared with the same method.And the performance of thermal conductivity additive was characterized in many aspects.3.The carbon nanotubes-dimethyl silicone oil with thermal conductive and lubricating performance that is prepared by the hybrid method,is conducted through theoretical analysis using the Maxwell-Garnett thermal conductivity model.The thermal conductivity mechanism and influencing factors of materials are analyzed and researched by analytical instrument.M-G model is sorted and revised according to the analyzed results.Finally,the exploration result shows that the predicted values are in consistent with the experimental ones.The COMSOL software simulate the thermally conductive lubricating materials’ industrial applicability,in the heat dissipation components of physical thermal field.The results show that the lubricating material with the best thermal conductivity has the best applicability and the lowest temperature during the heating process of mechanical operation.