| The BN-C-silicone oil composite colloid, which is manufactured by innovation based on the physicochemical characteristics of solid lubricants and the theory of bond energy, as well as the stability of silicone oil at elevated temperature, has enriched the recombining theory of multivariate lubricants and widened the industrial application fields of silicone oil.In the thesis, the development situation of colloid science, the preparation methods of ultra-micro/nano composite particles and their application status in lubrication field were summarized. Based on the review, a new concept about high temperature ultra-micro/nano lubricating colloid was presented. And silicone oil was adopted as the dispersing medium to prepare BN-C-silicone oil composite colloids with high temperature lubricating property by using high energy ball milling method.Based on the similar physical properties and similar crystal structure, together with the complementary lubricating properties, BN and C matched well when they were recombined. According to analyzing the valence electronic structure of BN and BN-C based on Empirical Electron Theory (EET), it was found that the lamellar bonds energy of BN-C compound (0.25673374 kJ/mol) was lower than that of BN (0.33129492kJ/mol), which meat that the slip between layers was easier to happen in BN-C compound. And lower lamellar bonds energy led to the smaller frictional coefficient.To achieve energy enough for the recombination of BN-C ultra-micro/nano particles, the planetary high energy ball mill was improved. An eccentric part was added to improve the impact energy of the planetary high energy ball mill. Then the stress, deformation of the particles and the milling efficiency were discussed through analyzing the kinetics and kinematics of the balls during the milling process. It was found that the milling efficiency was relative with revolution speed, proportion of revolution speed to rotation speed, eccentric distance and the diameter of the milling balls. These could be the theoretical reference for setting the milling technic parameters to prepare the ultra-micro/nano particles.Based on the colloid theory, nonionic surfactants were added to make the BN-C ultra-micro/nano composite particles suspend in silicone oil stably and avoid particle agglomeration. And the proportion of the selected surfactant was discussed. Then the surface modification mechanism of the colloidal particles was also discussed. Through modeling the relation between the size of particles and sedimentation speed, it was found that the BN-C particles could suspend stably in silicone oil if their diameters were less than 284.7 nm. These were the important theoretical basis for the preparation and dispersion stability of the colloid.The diameters of the ultra-micro/nano colloid particles and the elements in the particles were measured by SEM and EDS. And through analyzing the binding status of the colloid particles by using FTIR and XPS, it was found that the new compound was formed by B, C and N combining in atomic ways. The XRD analysis showed that the new compound had hexagonal crystal structure, which was similar to h-BN. Together with the theoretical slip analysis based on EET, this could be used for discussing the lubricating mechanism.The lubricating properties of the prepared composite colloid were measured by using XP-5 friction and wear tester. It was found that the colloid showed good lubricating property at whatever ambient and high temperature. And based on the microscopic analysis, the lubricating mechanism was discussed. Finally, considering the structure characteristic of the sweat-gland ceramic sinter, the lubricity of the colloid infiltrated in the sinter was also studied.
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