Abstract This study investigates the performance of three ionic liquids (ILs), trihexyl(tetradecyl)phosphonium bis(2,4,4-trimethylpentyl)phosphinate, trihexyl(tetradecyl)phosphonium decanoate, and 1-butyl-3-methylimidazolium tetrafluoroborate, as lubricant additives in synthetic oil polyalphaolefin (PAO8) and bio-based oil trimethylolpropane trioleate (TMPTO). The ILs were added at 0.5, 1.0, and 1.5 wt% concentrations and evaluated in terms of their miscibility with base oils as well as friction- and wear-reducing abilities. Four-ball and high-frequency reciprocating rig (HFRR) tribotesters were employed to evaluate the tribological performance under a boundary lubrication regime. Worn steel surfaces were characterized using optical microscopy, profilometry, scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX) analysis. The results suggested that the addition of trihexyl(tetradecyl)phosphonium bis(2,4,4-trimethylpentyl)phosphinate and trihexyl(tetradecyl)phosphonium decanoate improved the tribological performance of both PAO8 and TMPTO at an optimum concentration of 1 wt%. They showed good friction reduction, lower overall surface wear, and improved surface finishing. 1-Butyl-3-methylimidazolium tetrafluoroborate managed to improve the tribological performance of both base oils only at 0.5 wt%. A further increase in 1-butyl-3-methylimidazolium tetrafluoroborate concentration caused detrimental effects on the steel surface due to the formation of halogenic compounds.

中文翻译：

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使用离子液体作为钢-钢接触合成和生物基润滑剂添加剂的摩擦学改进

摘要 本研究研究了三种离子液体 (IL)、双（2,4,4-三甲基戊基）次膦酸三己基（十四烷基）鏻、癸酸三己基（十四烷基）鏻和四氟硼酸 1-丁基-3-甲基咪唑鎓作为润滑剂的性能。合成油聚 α 烯烃 (PAO8) 和生物基油三羟甲基丙烷三油酸酯 (TMPTO) 中的添加剂。IL 以 0.5、1.0 和 1.5 wt% 的浓度添加，并根据它们与基础油的混溶性以及减少摩擦和磨损的能力进行评估。采用四球和高频往复式钻机 (HFRR) 摩擦测试仪来评估边界润滑状态下的摩擦学性能。磨损的钢表面使用光学显微镜、轮廓测量法、扫描电子显微镜 (SEM) 和能量色散 X 射线 (EDX) 分析进行表征。结果表明，添加三己基（十四烷基）鏻双（2,4,4-三甲基戊基）次膦酸酯和三己基（十四烷基）鏻癸酸酯在 1 wt% 的最佳浓度下提高了 PAO8 和 TMPTO 的摩擦学性能。它们表现出良好的减摩效果、较低的整体表面磨损和改进的表面光洁度。1-丁基-3-甲基咪唑鎓四氟硼酸盐仅在 0.5 wt% 时就设法改善了两种基础油的摩擦学性能。由于卤素化合物的形成，1-丁基-3-甲基咪唑鎓四氟硼酸盐浓度的进一步增加对钢表面造成不利影响。4-三甲基戊基）次膦酸酯和三己基（十四烷基）鏻癸酸酯在 1wt% 的最佳浓度下改善了 PAO8 和 TMPTO 的摩擦学性能。它们表现出良好的减摩效果、较低的整体表面磨损和改进的表面光洁度。1-丁基-3-甲基咪唑鎓四氟硼酸盐仅在 0.5 wt% 时就设法改善了两种基础油的摩擦学性能。由于卤素化合物的形成，1-丁基-3-甲基咪唑鎓四氟硼酸盐浓度的进一步增加对钢表面造成不利影响。4-三甲基戊基）次膦酸酯和三己基（十四烷基）鏻癸酸酯在 1wt% 的最佳浓度下改善了 PAO8 和 TMPTO 的摩擦学性能。它们表现出良好的减摩效果、较低的整体表面磨损和改进的表面光洁度。1-丁基-3-甲基咪唑鎓四氟硼酸盐仅在 0.5 wt% 时就设法改善了两种基础油的摩擦学性能。由于卤素化合物的形成，1-丁基-3-甲基咪唑鎓四氟硼酸盐浓度的进一步增加对钢表面造成不利影响。