Tribological Performance and Lubrication Mechanism of Solid–Liquid Lubricating Materials in High-Vacuum and Irradiation Environments

Trihexyltetradecylphosphonium bis(2-ethylhexyl)phosphate (phosphonium phosphate) ionic liquid is soluble in non-polar lubricants. It has been proposed as an effective anti-wear additive comparable to zinc dialkyldithiophosphate. Previously, phosphonium phosphate has shown a better anti-wear performance under some conditions such as high temperature. In this work, the tribological performance and the lubrication mechanism of phosphonium phosphate are compared with that of zinc dialkyldithiophosphate when lubricating silicon under various tribological conditions. This can lead to an understanding of the reasons behind the superior anti-wear performance of phosphonium phosphate under some conditions. A micro-scale study is conducted using a nanotribometer. The results show that both additives lead to a considerable reduction in both friction and wear coefficients. The reduction in the wear coefficient is mainly controlled by the formation of the tribofilm on the rubbing surfaces. Zinc dialkyldithiophosphate can create a thicker tribofilm, which results in a better anti-wear performance. However, the formation of a thicker film will lead to a faster depletion and thus phosphonium phosphate can provide better anti-wear performance when the depletion of zinc dialkyldithiophosphate starts.

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The tribological performance of W-DLC in solid–liquid lubrication system addivated with Cu nanoparticles

Surface Topography Metrology and Properties ◽

10.1088/2051-672x/ac4086 ◽

2021 ◽

Author(s):

Dong shan Li ◽

Ning Kong ◽

Ruishan Li ◽

Boyang Zhang ◽

Yongshun Zhang ◽

...

Keyword(s):

Test Temperature ◽

Applied Load ◽

Tribological Performance ◽

Dominant Factor ◽

Lubrication System ◽

Cu Nanoparticles ◽

Friction Test ◽

Dlc Film ◽

Test Conditions ◽

Solid Liquid

Abstract Judicious selection of additives having chemical and physical compatibility with the DLC films may help improving the triboligical properties and durability life of DLC-oil composite lubrication systems. In this study, Cu nanoparticles were added to PAO6 base oil to compose a solid-liquid composite lubrication system with W-DLC film. The effects of nanoparticle concentration, test temperature and applied load on tribological performance were systematically studied by a ball-on-disk friction test system. The tribological results illustrated that Cu nanoparticles could lower the coefficient of friction (COF) and dramatically reduce the wear rates of W-DLC films. The optimal tribological behavior was achieved for the 0.1 wt.% concentration under 30 ℃ and the applied load of 100 N. The test temperature and applied load were vital influencing factors of the solid–liquid lubrication system. The bearing effect and soft colloidal abrasive film of spherical Cu nanoparticle contributed to the excellent tribological performance of the composite lubrication system under mild test conditions, meanwhile, the local delamination of W-DLC film and oxidation were the main causes of the friction failure under harsh test conditions. With test temperature and applied loads increase the degree of graphitization of the W-DLC film increased. In conclusion, there are several pivotal factors affecting the tribological performance of solid–liquid lubrication systems, including the number of nanoparticles between rubbing contact area, graphitization of the worn W-DLC films, tribofilms on the worn ball specimens and oxidation formed in friction test, and the dominant factor is determined by the testing condition.

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Conditions affecting the sliding tribological performance of selected coatings for high vacuum bearing applications

Wear ◽

10.1016/j.wear.2007.02.019 ◽

2007 ◽

Vol 263 (7-12) ◽

pp. 1300-1305 ◽

Cited By ~ 13

Author(s):

S.E. Franklin ◽

J. Baranowska

Keyword(s):

High Vacuum ◽

Tribological Performance

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A Study on the Tribological Performance of Nanolubricants

Processes ◽

10.3390/pr8111372 ◽

2020 ◽

Vol 8 (11) ◽

pp. 1372

Author(s):

Yeoh Jun Jie Jason ◽

Heoy Geok How ◽

Yew Heng Teoh ◽

Hun Guan Chuah

Keyword(s):

Wear Resistance ◽

Potential Application ◽

Environmentally Friendly ◽

Tribological Performance ◽

Lubricant Additives ◽

Lubrication Mechanism ◽

Base Oil ◽

Base Oils ◽

Dispersion Of Nanoparticles

In recent years, the tribology field has expanded with the advent of nanolubrication. Nanolubricants are the name given to the dispersion of nanoparticles in a base oil, and has attracted researchers due to its potential application. In addition to being used in the tribology field, nanoparticles are also used for medical, space, and composites purposes. The addition of nanoparticles in base oils is promising because it enhances specific tribological characteristics including wear-resistance and friction, and the most important reason is that the majority of them are environmentally friendly. This paper reviews the tribological effect of various nanoparticles as lubricant additives. Parameters of nanoparticles that affect tribological performance, the technique to enhance stability, and lubrication mechanism that is currently believed to function will be delineated in detail. Moreover, this review facilitates an understanding of the role of various nanoparticles, which helps in developing and designing suitable nanolubricants for various applications.

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