真空环境中离子液体的边界摩擦特性及润滑寿命评估研究

Many mechanical assemblies used in space rely on liquid to provide reliable lubrication throughout their mission lives. Longer life and better performance of lubricants are increasingly required. Ionic liquids with excellent thermal stability, good tribological property and low volatility show great potential for use in space mechanisms. In this research, two ionic liquids , namely 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide and trihexyl(trtradecyl)phosphonium tris(pentafluoroethyl)trifluorophosphate ,with the pour point blow -50℃ and the viscosity-temperature index higher than 100, will be evaluated by a home-made vacuum four-ball-tribometer to investigate their boundary lubrication characteristics in the vacuum environment. X-ray photoelectron spectroscopy and FT-IR analysis will be conducted to understand the chemical composition of the bounder film formed by rubbing and its evolution process. Oil degradation is a concern in spacecraft mechanisms, so in-situ mass spectroscopy inspection of the wear-induced chemical degradation product will be conducted to understand the degradation of the ionic liquid during friction in vacuum and the influence of the degradation on the ionic liquids tribological properties .The achievement of this work will provide theoretical basis and engineering guidance for ionic liquid space lubrication.

高性能润滑材料是包括卫星、飞船、空间站在内的空间飞行器运动机构长期可靠运行的重要保障，研究人员一直致力于寻求性能更好的润滑材料。离子液体因具备低挥发、高热稳定性、优良润滑抗磨性能而在空间环境中显示出良好的应用前景。本项目拟以具有低凝点（倾点低于-50℃）、良好粘温性能（粘温系数大于100）的两类离子液体：功能化咪唑离子液体和季膦盐离子液体为润滑剂，利用真空摩擦磨损试验机研究其真空边界润滑性能；通过真空摩擦试验机所装备的质谱检测仪原位分析摩擦过程中离子液体降解产物，研究真空边界摩擦条件下离子液体的降解过程与降解机制；利用能谱、表面红外光谱等现代表面分析技术研究真空环境中离子液体边界润滑膜的组成、结构及性能演化过程。通过大量试验研究和理论分析评估真空环境中不同运行条件下离子液体的边界润滑寿命并建立相关模型，为国家航天工程中相关运动部件的润滑提供理论依据和应用指导。

高性能润滑材料是包括卫星、飞船、空间站在内的空间飞行器运动机构长期可靠运行的重要保障，研究人员一直致力于寻求性能更好的润滑材料。离子液体因具备低挥发、高热稳定性、优良润滑抗磨性能而在空间环境中显示出良好的应用前景。本项目以咪唑盐和季磷盐两类典型离子液体的结构为基础，通过引入烯基、氟磺酰胺基、羟基、巯基嘧啶等官能团，设计合成了一系列功能化离子液体润滑剂；利用空间辐照、摩擦学和电化学等分析测试手段，考察了离子液体润滑剂抗空间辐照、减摩抗磨和缓蚀性能的变化规律，研究了真空边界摩擦条件下离子液体的降解过程与降解机制；利用能谱、表面红外光谱等表面分析技术研究了真空环境中离子液体边界润滑膜的组成、结构及性能演化过程，为国家航天工程中相关运动部件的润滑提供理论依据和应用指导。