普通离子液体润滑剂的润滑成膜性能研究  

Film Forming Characteristics of Common Ionic Liquid Lubricants

作　　者：解国新[1] 雒建斌[1] 郭丹[1] 刘书海[1] 肖华平[1] 路新春[1] 

机构地区：[1]清华大学摩擦学国家重点实验室,北京100084

出　　处：《机械工程学报》2011年第11期82-86,共5页Journal of Mechanical Engineering

基　　金：国家重点基础研究发展计划资助项目(973计划;2007CB607604;2009CB724404)

摘　　要：目前离子液体在机械润滑研究领域受到重视,但对离子液体润滑成膜能力的研究还不多。利用纳米级膜厚测量仪考察几种具有不同阳离子侧链长度的普通磷酸盐离子液体在不同压力下的成膜能力,同时利用相近粘度的硅油作为对比对象,探讨离子液体的润滑失效及抗压能力。结果表明,在卷吸速度较高时,这几种离子液体的润滑行为符合弹流润滑规律,而在较低卷吸速度时符合薄膜润滑规律。在薄膜润滑区域内,随着阳离子侧链长度的增加,由于单位体积内离子数的减少以及空间位阻效应的存在,接触区中心膜厚测量值与弹流理论计算值之间的差异变小;当卷吸速度降低到0.1 mm.s?1左右时,未见这几种离子液体存在流体膜的失效点。由于离子液体中离子与带电固体表面之间存在较强的静电作用,使离子液体比相近粘度的硅油具有更强的抗压能力。Ionic liquids now receive increasing attention in the mechanical lubrication research area.However,the film forming properties of ionic liquids are still rarely discussed.The film forming properties of several common phosphate ionic liquids with different side chain lengths of the cation are investigated under different pressures.Also,the lubrication failure and compression resistance of these ionic liquids are discussed by taking silicon oils with similar viscosities as comparative objects.The results show that the lubrication behaviors of these ionic liquids accord with the elastohydrodynamic lubrication（EHL） theory at high entraining speed and they accord with the thin film lubrication（TFL） theory at low entraining speed.With the increase of the side chain length of the cation,the difference between the measured central film thickness in the contact region and the calculated value according to the EHL theory tends to reduce in the TFL regime.It is primarily due to the decrease in the number of ions per unit volume and the effect of steric hindrance.When the entraining speed decreases to about 0.1 mm？s？1,no obvious lubrication failure point is observed for the tested ionic liquids.The ionic liquids possess better compression resistance than silicon oils with similar viscosities as a result of the strong electrostatic interaction between ions and charged solid surfaces.

关 键 词：离子液体 成膜能力 润滑失效 硅油 

分 类 号：TH117.2[机械工程—机械设计及理论]