Friction and Wear Reduction Mechanisms of the Reciprocating Contact Interfaces Using Nanolubricant Under Different Loads and Speeds

This study aims to reveal the roles and mechanisms of Al2O3/TiO2 hybrid nanoparticles into the lube oils which could reinforce engine components durability via reducing the friction, wear, or fuel economy in automotive engines. The tribological tests were carried out under different sliding speeds from 0.21 to 1.75 m/s and loads from 30 to 250 N using a reciprocating tribometer to simulate the ring/liner interface in the engine according to ASTM G181. The tribological results using hybrid nanolubricants suggested that the friction coefficient and wear rate of the ring decreased in the ranges 39–53% and 25–33%, respectively, compared to nanoparticles-free lube oil. The combined evidence of the worn surfaces analysis confirmed that the key mechanisms in antifriction and antiwear are a combination of the nanoparticles rolling mechanism and the replenishment mechanism of tribofilms on the sliding contact interfaces. In addition, a tribofilm formed on the rubbing surfaces is not only from the nanoparticles but also from Fe which is formed as a result of iron debris particles and oil additive package such as P and S originating from zinc dialkyldithiophosphate.

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Investigation of the Tribological Performances of Graphene and WS2 Nanosheets as Additives for Perfluoroalkylpolyethers Under Simulated Space Environment

Tribology Letters ◽

10.1007/s11249-021-01412-2 ◽

2021 ◽

Vol 69 (2) ◽

Author(s):

Jia Ren ◽

Kuiliang Gong ◽

Gaiqing Zhao ◽

Wenjing Lou ◽

Xinhu Wu ◽

...

Keyword(s):

Amorphous Carbon ◽

Atomic Oxygen ◽

Friction And Wear ◽

Surface Oxidation ◽

Space Environment ◽

Composition And Structure ◽

Before And After ◽

Wear Reduction ◽

Ws2 Nanosheets ◽

Effects Of Irradiation On

AbstractThe tribological performances of perfluoroalkylpolyethers (PFPE) with graphene (Gr), WS2, and the mixture of Gr and WS2 (Gr + WS2) before and after ultraviolet (UV), atomic oxygen (AO), and proton (Pr) irradiations were investigated. The composition and structure of PFPE, Gr, WS2, and Gr + WS2 were also analyzed to understand the effects of irradiation on the tribological behaviors of PFPE with additives. The results indicated that serious deterioration and degradation of PFPE took place and Gr was transformed to amorphous carbon after Pr irradiation, and surface oxidation of WS2 occurred under the irradiations of AO and Pr. Moreover, compared to PFPE and PFPE additized with Gr and WS2, PFPE with the addition of Gr + WS2 exhibited excellent friction and wear reduction before and after UV and AO irradiations. Graphical Abstract

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Tribological Behaviour of Graphene Nanoplatelets as Additive in Pongamia Oil

Coatings ◽

10.3390/coatings11060732 ◽

2021 ◽

Vol 11 (6) ◽

pp. 732

Author(s):

Yeoh Jun Jie Jason ◽

Heoy Geok How ◽

Yew Heng Teoh ◽

Farooq Sher ◽

Hun Guan Chuah ◽

...

Keyword(s):

Friction And Wear ◽

Graphene Nanoplatelets ◽

Friction Reduction ◽

Engine Oil ◽

Protective Film ◽

Tribological Behaviour ◽

Wear Reduction ◽

Pongamia Oil ◽

Interacting Surfaces ◽

Worn Surface

This study investigated the tribological behaviour of Pongamia oil (PO) and 15W–40 mineral engine oil (MO) with and without the addition of graphene nanoplatelets (GNPs). The friction and wear characteristics were evaluated in four-ball anti-wear tests according to the ASTM D4172 standard. The morphology of worn surfaces and the lubrication mechanism of GNPs were investigated via SEM and EDS. This study also focuses on the tribological effect of GNP concentration at various concentrations. The addition of 0.05 wt % GNPs in PO and MO exhibits the lowest friction and wear with 17.5% and 12.24% friction reduction, respectively, and 11.96% and 5.14% wear reduction, respectively. Through SEM and EDS surface analysis, the surface enhancement on the worn surface by the polishing effect of GNPs was confirmed. The deposition of GNPs on the friction surface and the formation of a protective film prevent the interacting surfaces from rubbing, resulting in friction and wear reduction.

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Oil-soluble ionic liquid to lubricate silicon

Proceedings of the Institution of Mechanical Engineers Part J Journal of Engineering Tribology ◽

10.1177/1350650120984880 ◽

2021 ◽

pp. 135065012098488

Author(s):

Waleed Al-Sallami ◽

Pourya Parsaeian ◽

Abdel Dorgham ◽

Anne Neville

Keyword(s):

Ionic Liquid ◽

High Temperature ◽

Friction And Wear ◽

Tribological Performance ◽

Considerable Reduction ◽

Zinc Dialkyldithiophosphate ◽

Lubrication Mechanism ◽

Wear Coefficient ◽

Wear Performance ◽

Micro Scale

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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Study of the Lubricating Ability of Protic Ionic Liquid on an Aluminum–Steel Contact

Lubricants ◽

10.3390/lubricants6030066 ◽

2018 ◽

Vol 6 (3) ◽

pp. 66 ◽

Cited By ~ 11

Author(s):

Akshar Patel ◽

Hong Guo ◽

Patricia Iglesias

Keyword(s):

Ionic Liquid ◽

Friction And Wear ◽

Constant Load ◽

Economic Losses ◽

Contact Friction ◽

Wear Volume ◽

Sliding Velocity ◽

Protic Ionic Liquid ◽

Wear Reduction ◽

Pin On Disk

Contact friction between moving components leads to severe wear and failure of engineering parts, resulting in large economic losses. The lubricating ability of the protic ionic liquid, tri-[bis(2-hydroxyethylammonium)] citrate (DCi), was studied as a neat lubricant and as an additive in a mineral oil (MO) at various sliding velocities and constant load on an aluminum–steel contact using a pin-on-disk tribometer. Tribological tests were also performed at different concentrations of DCi. When DCi was used as an additive in MO, friction coefficient and wear volume were reduced for each sliding velocity, with a maximum friction and wear reduction of 16% and 40%, respectively, when 2 wt % DCi was added to MO at a sliding velocity of 0.15 m/s. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) were also applied to analyze the wear mechanism of the interface lubricated by MO and DCi as additive.

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Surface and Tribological Characterization of Coatings for Friction and Wear Reduction

10.4271/932787 ◽

1993 ◽

Cited By ~ 1

Author(s):

Steven J. Simko ◽

Maria C. Militello ◽

Simon C. Tung

Keyword(s):

Friction And Wear ◽

Wear Reduction ◽

Tribological Characterization

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Friction and Wear Reduction of 440C Stainless Steel by Ion Implantation

MRS Proceedings ◽

10.1557/proc-27-661 ◽

1983 ◽

Vol 27 ◽

Cited By ~ 10

Author(s):

L. E. Pope ◽

F. G. Yost ◽

D. M. Follstaedt ◽

S.T. Picraux ◽

J. A. Knapp

Keyword(s):

Stainless Steel ◽

Surface Layer ◽

Yield Strength ◽

Ion Implantation ◽

Friction And Wear ◽

No Reduction ◽

Wear Reduction ◽

Amorphous Surface ◽

Wear Tests ◽

Friction And Wear Tests

ABSTRACTFriction and wear tests on ion-implanted 440C stainless steel discs have been extended to high Hertzian stresses (≤ 3150 MPa). Implantation of 2 × 1015 Ti/mm2 (180–90 keV) and 2 × 1015 C/mm2 (30 keV) into 440C reduces friction (∼40%) and wear (> 80%) for Hertzian stresses as large as 2900 MPa, stresses which significantly exceed the yield strength of 440C (∼1840 MPa). Implantation of 4 × 1015 N/mm2 (50 keV) into 440C reduces friction slightly (∼25%) for Hertzian stresses > 1840 MPa but provides little or no reduction in wear. The amount of Ti remaining in the wear tracks correlates with the reductions in friction and wear. The implantation of Ti and C produces an amorphous surface layer which is believed to reduce friction and wear, whereas N implantation is expected to produce hard nitride particles which probably do not modify the hardness of 440C (KHN = 789) significantly.

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