Friction-Induced Amorphization with ZDDP—An EXAFS Study

Martin, Jarad; Belin, M.; Mansot, Jean-Louis; De×pert, H.; Lagarde, P.

doi:10.1080/05698198608981716

Cited by 75 publications

(24 citation statements)

References 6 publications

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“…As demonstrated in previous works [3][4][5][6][7][8][9][10] related to the boundary lubrication regime, the friction and wear processes, in the case of conventional additives, are associated to the formation, on the sliding surfaces, of a protective tribofilm resulting from chemical reactions between additives molecules and surfaces. This action mechanism implies that the tribofilm is not immediately formed on the surfaces and the antiwear efficiency is modulated by the reactivity of the additives with the sliding materials.…”

Section: Introductionmentioning

confidence: 93%

Friction Properties of Fluorinated Carbon Nanodiscs and Nanocones

Pandorf¹,

Himmel²,

Mansot³

et al. 2010

Tribol Lett

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The tribologic properties of carbon nanodiscs and nanocones and their fluorinated derivatives are investigated and correlated to their structure and chemical composition (atomic fluorine/carbon ratio). Two families of products are studied obtained by fluorination of ill ordered and highly graphitized carbon nanodiscs and nanocones. The studies clearly point out that friction properties of the nanoparticles are strongly dependent on the structure of the initial carbonaceous compounds. Better tribologic behaviour is obtained when the initial nanoparticles structure is highly ordered (graphitized particles). In that case, an optimum of fluorination rate is put in evidence.

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Section: Introductionmentioning

confidence: 93%

Friction Properties of Fluorinated Carbon Nanodiscs and Nanocones

Pandorf¹,

Himmel²,

Mansot³

et al. 2010

Tribol Lett

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“…The anti-wear mechanisms of metal dithiophosphate lubricant additives are known to involve a complex polyphasic chemical reaction. The most important reaction process has been recognised to be the formation of a solid transition metalphosphate glass material as an adherent thin film [1,2]. This film acts as a protective layer against wear, due to its superplastic behaviour in the contacting zone.…”

Section: Introductionmentioning

confidence: 99%

Tribochemistry of ZDDP and MoDDP chemisorbed films

et al. 1996

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By means of a UHV analytical AES/XPS pin-on-flat tribotester, we have investigated tribochemical change as well as transfer mechanisms in static reaction films on steel from ZDDP (anti-wear) and MoDDP (friction modifier) lubricant additives. The results show that solid ZDDP reaction films are able to strongly reduce friction to a value of 0.1-0.3 (in the absence of a film, steel-on-steel gives a friction coefficient value of up to 2). MoDDP reaction films produce ultra-low friction (below 0.05) after an induction period. In situ AES analysis and energy-filtered XPM gave definitive evidence of frictioninduced chemical changes and selective material transfer from the flat to the pin. In the ease of MoDDP, the thiophosphate film is decomposed and a "MoS2" residual film is found in the wear scar on the pin.

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“…Over the years, lots of microstructural studies and investigations related to the chemical nature of the reaction layers were done. In particular, Martin et al applied analytical techniques such as electron energy loss spectroscopy (EELS), X-ray adsorption fine structure analysis (EXAFS) or X-ray absorption near-edge spectroscopy (XANES) to reveal the chemical composition and structure of said layers [10][11][12][13]. Despite the use of high resolution and sophisticated analytical methods, there is still a controversial issue concerning the specific reaction pathways and kinetics of the ZDDP layer formation [1].…”

Section: Introductionmentioning

confidence: 99%

Microstructural and Chemical Characterization of the Tribolayer Formation in Highly Loaded Cylindrical Roller Thrust Bearings

et al. 2016

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Zinc dithiophosphates (ZDDP) have been widely applied in automobile industry for over 70 years as a lubricant additive for wear protection. Tribolayers have been described as blue-and brown-colored layers on surfaces observed by microscopical observation or even bare eye presumably as a consequence of layer thickness or chemical composition. However, the reaction pathways of ZDDP tribolayers are still not yet fully understood. In the present study, the difference between the blue-and brown-colored tribolayers has been revealed by high resolution methods in cylindrical roller thrust bearings at relatively high contact pressures of around 1.92 GPa. After running a FE8 standard bearing test with a normal load of 80 kN and a temperature of 60˝C, said tribolayers could be identified on the bearing surfaces. By using Raman spectroscopy, it could be shown that the blue-colored layers are enriched by FeS and ZnS whereas the brown-colored layers show a significant amount of Fe 3 O 4 . This is an interesting finding as it clearly shows a correlation between the color appearance of the films and the chemical composition besides potential film thickness variations. Finally, transmission electron microscopy verified the amorphous nature of the formed tribolayer which is in a good agreement with literature.

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Friction-Induced Amorphization with ZDDP—An EXAFS Study

Cited by 75 publications

References 6 publications

Friction Properties of Fluorinated Carbon Nanodiscs and Nanocones

Friction Properties of Fluorinated Carbon Nanodiscs and Nanocones

Tribochemistry of ZDDP and MoDDP chemisorbed films

Microstructural and Chemical Characterization of the Tribolayer Formation in Highly Loaded Cylindrical Roller Thrust Bearings

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