含膦酸酯官能团离子液体对钢/铝摩擦副的润滑作用研究

合成了3种新型1-(O,O-二乙基膦酰丙基)-3-烷基咪唑六氟磷酸盐离子液体,采用SRV型摩擦磨损试验机评价了所制备的离子液体作为润滑剂对钢／铝摩擦副摩擦学性能的影响,并探讨了其润滑机理．结果表明,所合成的离子液体作为润滑剂对钢／铝摩擦副具有优良的润滑作用,摩擦系数低,抗磨性能优良．表面分析结果表明含膦酸酯官能团的离子液体在摩擦副接触表面形成化学吸附边界润滑膜,从而有效地起到抗磨和提高承载能力的作用．

Lubricity of Ionic Liquids Containing Phosphonate Functional Groups as Lubricants for Aluminum-on-Steel Contact

A series of novel functional room-temperature ionic liquids (RTILs) of 1-(O,O-diethyl phosphonyl-n-propyl)-3-alkylimidazolium hexafluorophosphate was prepared and evaluated as a kind of promising lubricant for aluminum-on-steel contact. The viscosity and density of the synthetic RTILs were measured. The glass transition temperature and the heat capacity jump associated with the transition from the non-equilibrium glass to the metastable supercooled liquid were analyzed. The lubricity of the synthetic RTILs as the lubricants for a aluminum-on-steel contact was comparatively investigated on an SRV test rig in a ball-on-disc configuration, using conventional ionic liquid 1-propyl-3-octylimidazolium hexafluorophosphate (coded as LP308) as a comparison. The worn Al alloy surfaces lubricated with different mediums were observed on a scanning electron microscope, while the chemical states of some typical elements in the neat synthetic ionic liquids and on the worn Al surface lubricated therewith were analyzed by means of X-ray photoelectron spectroscopy. It was found that the new ionic liquids showed higher viscosity than LP308. The synthetic ionic liquids had excellent friction-reducing and antiwear ability to the aluminum-on-steel contact and were superior to phosphazene (X-1P) in terms of the friction-reduction ability and load-carrying capacity, which was attributed to the formation of chemical adsorption and tribo-chemical reaction boundary film on the worn surface during sliding process. Of the three synthetic ionic liquids, showed the best lubricity and antiwear ability for the aluminum-on-steel system.