油溶性离子液体作为镍基合金润滑添加剂的摩擦学性能研究

Tribological Properties of Oil-soluble Ionic Liquids Used as Lubrication Additives for Nickel-based Alloys

目的合成一种无卤素油溶性离子液体润滑添加剂(P88816-Phosphate,以下简称PP),提高PAO 40作为硬质合金/镍基合金Inconel 690润滑剂的摩擦学性能。方法以PP为添加剂,在PAO 40基础上配制质量分数为0.5%、1%、2%的润滑剂,与PAO 40进行对比。采用同步热分析仪分析其热稳定性,采用SRV-IV微动摩擦磨损试验机、MicroXAM-800非接触三维表面轮廓仪考察该离子液体减摩抗磨添加剂的摩擦学性能。结果在50℃条件下,PP可以明显地提高PAO 40的减摩抗磨性能。1%PP的效果最为明显,摩擦因数降低了约22%,磨损体积减小了约48%。150℃条件下,0.5%PP的摩擦因数最低,而且磨损体积也是最小。结论PP中活性元素P与金属基底发生摩擦化学反应,生成了摩擦化学反应膜。油溶性离子液体在镍基合金表面形成的润滑膜结构,可以揭示油溶性离子液体在减少金属摩擦和磨损方面的作用机制。PP有望为镍基合金提供更好的润滑保护,减少摩擦和磨损,延长设备的使用寿命,提高工业生产效率。

Soluble ionic liquid is a kind of organic salts with unique structures and properties that provide high thermal stability,low volatility,and excellent lubricating properties.It also has good thermal and chemical stability,which allows it to maintain its lubricating properties at high temperature and in harsh environments,thereby improving the tribological properties and service life of nickel-based alloys.It can be used as an alternative to greases and conventional lubricants to reduce energy loss and coefficient of friction in metal materials during friction and wear.In the study of tribological properties of nickel-based alloy lubrication additives,the effect of soluble ionic liquids is usually evaluated by tribological experiments.The effect of lubricants on performance indicators such as coefficient of friction,frictional wear,and surface fatigue are tested.Some studies have shown that the use of soluble ionic liquids as lubricant additives can significantly reduce the coefficient of friction and wear of nickel-based alloys.This is because soluble ionic liquids form a protective lubricating film on the metal surface,reducing direct metal-to-metal contact and friction.In this study,a halogen-free oil-soluble ionic liquid lubricant additive,denoted as P88816-Phosphate(hereinafter referred to as PP)was successfully synthesized,and incorporated into a base oil polyα-olefin(PAO 40).Comprehensive assessments were conducted to evaluate its effect on the viscosity-temperature behavior,thermal stability and performance variation when it was employed as a lubricant in a friction pair composed of cemented carbide/nickel-based alloy Inconel 690 under the temperatures of 50 and 150℃.A synchronous thermal analyzer was used to analyze the thermal stability of the material.SRV-Ⅳmicro-moving friction and wear testing machine and MicroXAM-800 non-contact three-dimensional surface profiler were used to investigate the tribological properties of the ionic liquid anti-friction and anti-wear additive.PP significantly improved the anti-friction and anti-wear properties of PAO 40 at 50℃.Noteworthy,the addition of 1%PP resulted in the most pronounced improvement,yielding a reduction of approximately 22%in the coefficient of friction and a decrease in wear volume of about 48%.Conversely,at the elevated temperature of 150℃,0.5%PP exhibited the lowest coefficient of friction,accompanied by the smallest wear volume.The lubrication mechanism was elucidated by SEM,EDS and XPS.The findings reveal that the active element phosphorus(P)within PP undergoes a tribochemical reaction with the metal substrate,leading to the formation of a tribochemical reaction film.This film effectively enhances the lubricating properties of the base oil and significantly augments the wear resistance of the friction pair.