基于流向引导型功能表面的润滑油防爬策略研究

Migration is a phenomenon that a lubricant can spread in a certain direction without external forces. Note that the lubricants for the space machinery are always of limited dosage, lubricants migration loss is one of the major reasons which can result in the failures of lubrication system. Therefore, it is of great significance to regulate and control the lubricants migration to guarantee the longtime and stable running of the space machinery. In this project, the surface/interface regulation methods will be researched, micro-machining techniques will be used to fabricate the gradient surface texture and functional coating; the direction-guide mechanism of the functional surface under the effect of thermal gradients will be elucidated; then, the influences of the morphology and the size of the functional surface on the direction-guide capacity will be investigated systematically to achieve controllable direction-guided surface to re-guide and re-locate the lapsed lubricants precisely; on that basis, the theoretical model will be built to predict the migration performance on the functional surface, and its migration-lubrication properties under complex conditions will be studied; finally, the designing principle of the functional surface with initiative regulation and excellent lubrication features will be proposed; the theory obtained in this research would be significant in the anti-migration strategies for lubrication under the special working conditions such as the space.

“蠕爬”是指润滑剂不受外力作用的定向扩展现象。鉴于空间机械中润滑剂含量少，润滑剂蠕爬损耗是其润滑系统失效的主要原因之一。因此，蠕爬控制对空间机械持久稳定运行具有重要意义。本项目拟采用表面/界面调控的方法，通过微细加工等技术制备梯度表面织构和功能涂层，揭示其在温度梯度作用下的流向引导机理；进一步阐明表面尺度/形态与引流特性的映射关系，从而获得引流能力可控的防爬表面，实现润滑油的精准引导与定位；在此基础上，建立功能表面润滑油热驱动蠕爬的理论模型，并探索多因素协同作用下流向引导型功能表面的蠕爬-润滑特性；最终提出具备主动调控能力和优异润滑特性的功能表面设计理论，为空间等特殊工况下润滑油的防爬设计提供依据。

项目围绕润滑油热驱蠕爬流失问题，探索了典型固体材料和液体润滑油的热驱蠕爬特性，提出了可快速评估不同润滑油在固体表面蠕爬行为的一般性准则；构筑了具有自驱流动特性的微纳功能表面，实现了润滑油的精准引导与调控；阐明了影响自驱流动能力的关键参数，提出了流向引导型功能表面的设计原则；在经典流体热力学和润滑近似理论基础上，建立了功能表面润滑油热驱蠕爬理论；利用分子动力学模拟，从分子尺度揭示了热驱蠕爬机制；开发了微磨料多相射流加工技术，丰富了表面织构加工手段；探索了基于功能表面的液体支撑、气泡调控、液滴碰撞特性，拓宽了功能表面应用领域；首次阐明了固体表面、面/面界面、球/面界面三类典型工况下润滑油热驱流动机制。项目的研究成果不仅丰富了热流体力学的基础知识，而且为服役于航空航天、深空探索领域服役在极端温差环境下的机械部件润滑系统设计供了科学的指导。