Page 211 - 《摩擦学学报》2021年第6期

996 摩 擦 学 学 报 第 41 卷

studied as lubricant oils and lubricant additives. In our work, laser processing technology was used to construct circular
dimple texture patterns with different diameters on titanium alloy (Ti-6Al-4V) surface. Two kinds of ionic liquids （1-
butyl-3-methylimidazolium Bis(trifluoromethanesulfonyl)-imide and Tributyltetradecyl phosphonium Bis(2-ethylhexyl)-
phosphate) were synthesized and characterized. MS-T3001 tribometer was used to test friction coefficients of Ti-6Al-4V
surfaces under different conditions, which included surfaces with and without circular dimple texture, with and without
ionic liquids, and the lubricant combination of textured surfaces and ionic liquids. Before friction process, the texture of
circular pits was observed on a metallurgical microscope. A scanning electron microscope was used to analyze the
morphology of the textured surface before and after rubbing. ANSYS Fluent software was used to simulate and analyze
the influence mechanism of surface texture parameters and ionic liquid’s viscosity on tribological performance. In
experimental process, both textured surface and ionic liquid exhibited good friction-reduction behavior. Wear scar
analysis were also consistent with the decreasing trend of friction coefficient. Lower friction coefficients from textured
surfaces could be attributed to dimple’s collecting and storing worn debris. Tribological performances of ionic liquids
were excellent due to their special physical and chemical properties. In the lubricant combination system, size
parameters of textured surface and species of ionic liquid were chosen to optimize tribological properties. Under the
combination conditions, it was found that friction coefficients decreased with the increase of diameters of the circular
dimple texture and the ionic liquid with higher viscosity also provided better friction-reduction behavior. Two-
dimensional simplified simulation of friction process was carried out in ANSYS Fluent to simulate the lifting force in the
lubricant combination. As the lubricant fluid, ionic liquid produced a wedge effect in the convergence interval, which
generated a lifting force on the upper friction pair. The simulation results showed that in the lubricant combination, the
friction coefficients decreased with the increase of diameter of the circular dimple on textured surfaces, simultaneously
ionic liquid with higher viscosity producing a higher lifting force on the upper friction pair. The simulated results about
the lubricant combination of surface texture and ionic liquids were consistent with the experimental results, which
confirmed to optimize the tribological performance by tuning the size of texture surface and choosing the species of
ionic liquids.
Key words: surface texture; ionic liquid; lubricant combination; titanium alloy; simulation

钛合金因具有较高的耐腐蚀性、良好的韧性及比 的研究，其摩擦学性能和润滑机理的研究受到研究人
[24]
强度等许多优异的性能而被广泛地应用于航天航空、 员的重视 [20-23] . 2001年，叶承峰等 认识到离子液体具
船舶和生物医学等领域 [1-3] ，但钛合金在负载条件下耐 有优异的润滑性能，开启了离子液体摩擦学的研究.
[4]
磨性能较差，尤其对粘着磨损较为敏感 . 数十年来的 将各种官能团引入到离子液体的阳离子或阴离子上，
摩擦学研究表明 [5-6] ，摩擦副表面粗糙度能够极大地影 或改变阴阳离子组合，进而设计合成具有不同分子结
响减摩抗磨性能，织构化表面能够提升系统的减摩抗 构的离子液体，进而提升离子液体的摩擦学性能 [25-27] .
[10]
[14]
[15]
磨 [7-9] 、增摩 、减振 [11-13] 、抗粘附 及抗蠕爬 等诸多 但将离子液体与表面织构复合润滑的研究相对较少.
[16]
[28]
性能，在相关领域已经显示了良好的应用前景 ，能 蒲吉斌等 在单晶硅表面制备了图案化类金刚石碳
够适用于严峻的工作环境. 复合薄膜，并在其表面涂覆离子液体固态薄膜，探究
表面织构对材料摩擦学性能的影响取决于织构 不同载荷下的摩擦学性能. Thakre等 通过讨论7种不
[29]
的形状、参数及加工精度等多种因素. 随着加工技术 同离子液体在不同粗糙度的等高线面、三角形面和锯
的不断进步，压印加工、磨粒喷射加工、机械振动加 齿形面上的微观润滑行为，发现表面织构、摩擦副材
工、电解加工以及激光加工等不同加工技术能够在不 料和离子液体的组合对摩擦副表面接触行为具有显
同种类材料表面制备精度较高的织构 . 其中激光加 著影响，选择合适的组合可以提升离子液体润滑性能.
[17]
工技术因其高效、高精度和对环境无污染等原因被广 目前有关润滑条件下织构表面的摩擦过程仿真
[7]
[30]
[18]
泛应用 . 胡丽天等 研究了激光加工制备的不同孔 较多利用纳维-斯托克斯(N-S)方程进行计算 . 王洪
[19]
径织构对摩擦学性能的影响. Mishra等 在空调或制 涛等 基于N-S方程通过计算流体动力学(CFD)建立
[31]
冷设备中的钛合金材料表面构建微点阵图案，发现图 了流体动压润滑模型以研究织构半径、深度、面积率
案密度和运动速度影响摩擦磨损性能. 及相对滑动速度对摩擦系数和动压承载能力的影响.
[32]
近20年来，离子液体作为润滑剂受到了广泛深入 Mezghani等 通过理论和试验方法研究了活塞环表