Tribological Properties Of Water-based Lubricant Added With Protic Ammonium Ionic

Nowadays,with the shortage of resources and environmental pollution becoming more and more serious,water-based lubricants have attracted more and more attention by virtue of green pollution-free advantages.However,due to the low viscosity and poor film forming ability of pure water,it cannot meet the requirements of lubricant under actual working conditions.So it is necessary to add suitable additives to improve their performance.As a new field,ionic liquids have received widespread attention and have been proven to be as good as lubricants and lubricant additives in recent years.Therefore,Two new types of ionic liquids were selected:Bis[(2-hydroxyethyl)ammonium]caprylate(BAA)and Bis[(2-hydroxyethyl)ammonium]myristate(BAM)as water-based lubricating fluid additive,equipped with different concentrations of aqueous solution,were conducted a series of tribological experiments.(1)The effects of ionic liquid concentration,rotating speed and load on friction and wear resistance were investigated.The stability and extreme pressure properties of the two solutions were studied experimentally by four-ball tester.The results show that BAM aqueous solution has better friction-reducing and lubrication stability and is stable at high speed and heavy load;BAA aqueous solution has better anti-wear performance under medium and low load,However,due to the low viscosity and thin film,the lubricating film is likely to fail under higher load.(2)The rheological performances of the two solutions were analyzed by a rotary rheometer.It is proved that the ionic liquid aqueous solution has good Newtonian fluid properties.(3)The wettability of the solution was studied by contact angle measuring instrument.It was found that the viscosity of BAM aqueous solution was higher,but the wettability was better,indicating that there was no direct connection between viscosity and wettability.(4)The film forming ability was studied by nanometer film thickness measuring instrument.It was found that both solutions have good film forming ability,and the film forming performance of BAM solution was more excellent.The film thickness of 5%BAM solution was about 28 nm,higher than that of the non-ionic liquid lubricant with the same viscosity.The research on ionic liquids provides a new direction for exploring new water-based lubricant additives,and lays a good foundation for the future theory and practice of ionic liquid water-based lubricating fluids.The experimental results show that ionic liquid aqueous solutions have good tribological properties and industrial application value.