scholarly journals Graphene Oxide Nanosheets as Effective Friction Modifier for Oil Lubricant: Materials, Methods, and Tribological Results

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Adolfo Senatore ◽  
Vincenzo D'Agostino ◽  
Vincenzo Petrone ◽  
Paolo Ciambelli ◽  
Maria Sarno
Keyword(s):  
Graphene Oxide ◽  
Wide Spectrum ◽  
Frictional Coefficient ◽  
Mineral Oil ◽  
Friction Reduction ◽  
Protective Film ◽  
Graphene Oxide Nanosheets ◽  
Tribological Behaviour ◽  
Friction Modifier ◽  
Base Oil

The tribological behaviour of graphene oxide nanosheets in mineral oil was investigated under a wide spectrum of conditions, from boundary and mixed lubrication to elastohydrodynamic regimes. A ball-on-disc setup tribometer has been used to verify the friction reduction due to nanosheets prepared by a modified Hummers method and dispersed in mineral oil. Their good friction and antiwear properties may possibly be attributed to their small structure and extremely thin laminated structure, which offer lower shear stress and prevent interaction between metal interfaces. Furthermore, the results clearly prove that graphene platelets in oil easily form protective film to prevent the direct contact between steel surfaces and, thereby, improve the frictional behaviour of the base oil. This evidence is also related to the frictional coefficient trend in boundary regime.

scholarly journals NOVEL NANOSIZED FRICTION MODIFIERS FOR ENGINE, GEARBOX AND ROLLING BEARINGS LUBRICANTS

2015 ◽  
Vol 6 (1) ◽  
Author(s):  
Adolfo Senatore ◽  
Maria Sarno ◽  
Paolo Ciambelli
Keyword(s):  
Graphene Oxide ◽  
Wide Spectrum ◽  
Frictional Coefficient ◽  
Mineral Oil ◽  
Friction Reduction ◽  
Antiwear Additives ◽  
Protective Film ◽  
Wear Properties ◽  
Rolling Bearings ◽  
Group I

In this paper the tribological performances of graphene oxide nanosheets in mineral oil under wide spectrum of conditions, from boundary and mixed lubrication to elastohydrodynamic regimes, are reported. Nanosheets of graphene oxide prepared by a modified Hummer method have been dispersed in Group I mineral oil. The formulated lubricant has been tested through a ball on disc setup tribometer to quantify the friction reduction with respect to the base mineral oil. The good friction and anti-wear properties of the graphene-oil mixture may possibly be attributed to the small structure of the nanosheets and their extremely thin laminated structure, which offer lower shear stress and prevent direct interaction between metal asperities in engine applications as well as gearbox environment. The results clearly prove that graphene platelets in oil easily form protective film to prevent the direct contact between steel surfaces and, thereby, improve the frictional behaviour of the base oil. This evidence is also related to the frictional coefficient trend in the boundary regime. Furthermore, hybrid organic–inorganic nanocomposites with different composition were successfully tested as antifriction and antiwear additives for grease lubricants as potential breakthrough media in rolling bearings applications.

scholarly journals Tribological Behaviour of Graphene Nanoplatelets as Additive in Pongamia Oil

Coatings ◽  
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.

scholarly journals Tribological investigation of applicability of nano-sized cupricoxide (CuO) ceramic material in automotive vehicles

2021 ◽  
Vol 49 (2) ◽  
pp. 335-343
Author(s):  
Álmos Tóth ◽  
Á.I. Szabó ◽  
R. Kuti ◽  
J. Rohde-Brandenburger
Keyword(s):  
Internal Combustion Engines ◽  
Protective Film ◽  
Combustion Engines ◽  
Wear Scar Diameter ◽  
Friction Modifier ◽  
Working Mechanism ◽  
Base Oil ◽  
Copper Material ◽  
Group 3 ◽  
Ball On Disc

Due to the continuously increasing requirements of the internal combustion engines, the lubricants and their additives have to be further developed. One possible solution is the application of ceramic nanoparticles as friction modifier and wear decreaser additives. This paper presents the tribological investigation of cupricoxide (CuO) nanoparticle mixed in neat Group 3 base oil. To analyse its properties, simplified ball-on-disc friction experiments were carried out in the tribological laboratory in the Széchenyi István University in Győr, Hungary. The arisen wear scars were analysed with different, highresolution microscopes to understand the working mechanism of the nanoparticles. The results have indicated an optimum concentration of nanoparticles at 0.5wt% where both the average friction coefficient and the wear scar diameter were reduced by 15%. The microscopical investigation revealed the reduction of copper material from the CuO material, and it has mended to the rubbing surface forming a protective film on the metal surface.

Tribological behaviour of graphene oxide sheets as lubricating additives in bio-oil

2018 ◽  
Vol 70 (8) ◽  
pp. 1396-1401 ◽  
Author(s):  
Daoyi Wu ◽  
Yufu Xu ◽  
Lulu Yao ◽  
Tao You ◽  
Xianguo Hu
Keyword(s):  
Graphene Oxide ◽  
Friction Coefficient ◽  
Wear Loss ◽  
Tribological Behaviour ◽  
Low Friction ◽  
Content Type ◽  
Base Oil ◽  
Lubricating Film ◽  
Bio Oil ◽  
Practical Implications

Purpose This paper aims to study the upgradation of the lubricating performance of the renewable base oil , and to study the tribological behavior of graphene oxide (GO) sheets used as lubricating additives in bio-oil for iron/steel contact. Design/methodology/approach A multifunctional end-face tribometer was used to characterize the friction coefficient and wear loss of the tribosystem under different lubricants. Findings The experimental results show that GO sheets with small size benefit lubricating effects and the optimal concentration of GO sheets in bio-oil is 0.4-0.6 per cent, which can form a complete lubricating film on the frictional interfaces and obtain a low friction coefficient and wear loss. Higher concentration of GO sheets can result in a significant aggregation of the sheets, reducing the content of the lubricating components in the bio-oil, which results in the increase in friction and wear; at this stage, the main wear pattern was ascribed to adhesive wear. Practical implications These results show a promising prospect of improving the tribological performance of renewable base oil with the introduction of GO sheets as additives. Originality/value No literature has covered the tribological behaviour of GO sheets in bio-oil. This study contributes to accelerating the application of bio-oil.

Tribological performance of nanolubricants dispersed with graphene oxide and detonation nanodiamond

2020 ◽  
pp. 135065012097734
Author(s):  
Abdulhakeem Javeed ◽  
Bibin John
Keyword(s):  
Graphene Oxide ◽  
Coefficient Of Friction ◽  
Surface Texture ◽  
Friction And Wear ◽  
Wear Track ◽  
Friction Reduction ◽  
Engine Oil ◽  
Test Duration ◽  
Detonation Nanodiamond ◽  
Base Oil

Different compositions of graphene oxide (GO) and detonation nanodiamond (DND) nanoparticles with API CH-4 engine oil were tested on a reciprocating wear tester at high contact pressure. Significant reductions in friction and wear were observed. Wear surfaces were characterized by a 3D profiler, scanning electron microscopy and energy-dispersive X-ray spectroscopy to determine the surface topography, film build-up composition, mechanism of nanoadditive-assisted friction reduction and wear reduction characteristics. The wear tests indicated that the original engine liner segments containing surface texture with oil retention potential significantly lose their micropeaks and valleys during the test. Even though the surface texture got disturbed, the presence of nanoadditives in the lubricant led to a reduction in the coefficient of friction. Considerable reduction in the roughness level of the wear track associated with the use of a nanolubricant was also explored through the 3D profiler analysis. The surface roughness of the wear track produced while using a nanolubricant with 0.5 mg/l of detonation nanodiamond nanoparticles was 66% lower than the roughness of the wear track obtained with the base oil. The nanolubricant suspended with 1 mg/l detonation nanodiamond nanoparticles achieved a lower coefficient of friction earlier and a combination of detonation nanodiamond and GO at 0.5 mg/l concentration achieved the lowest coefficient of friction and wear at the end of the test duration.

scholarly journals Influence of structural factors on the tribological performance of organic friction modifiers

Friction ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 380-400
Author(s):  
Febin Cyriac ◽  
Xin Yi Tee ◽  
Sendhil K. Poornachary ◽  
Pui Shan Chow
Keyword(s):  
Metal Surface ◽  
Internal Combustion Engines ◽  
Chemical Reactivity ◽  
Friction Reduction ◽  
Composition Analysis ◽  
Protective Film ◽  
Structural Factors ◽  
Friction Modifiers ◽  
Base Oil ◽  
Lubrication Performance

AbstractThe influence of structural factors on the lubrication performance of organic friction modifiers (OFMs) formulated in Group V (polyol ester oil) base oil was studied using a ball-on-disk tribometer. The results show that OFMs can mitigate friction under heavy loads, low sliding speeds, and high temperatures. These conditions are commonly encountered in internal-combustion engines between cylinder liners and piston rings. The reduction in friction is ascribed to the boundary lubrication film containing the OFM. The chemical composition analysis of the metal disk surface using energy dispersive X-ray spectroscopy (EDS) confirmed the presence of a protective film of OFM on the wear track, albeit inconsistently deposited. Although the adsorption of the OFM on the metal surface was observed to be dependent on the chemical reactivity of the functional groups, levels of unsaturation, and hydrocarbon chain length of the OFM, the frictional performance was not always directly correlated with the surface coverage and tribofilm thickness. This implies that the friction reduction mechanism can involve other localized processes at the interface between the metal surface and lubricant oil. The occasional variation in friction observed for these OFMs can be attributed to the stability and durability of the boundary film formed during the rubbing phase.

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