Effects of some chemical factors on film failure under EP conditions

Tomaru, M.; Hironaka, Seiichiro; Sakurai, Takeshi

doi:10.1016/0043-1648(77)90197-1

Cited by 36 publications

(11 citation statements)

References 10 publications

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“…A significant amount of work has already been carried out to examine the tribological properties of these types of additives. [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] In addition, the surface chemistry of a wide range of sulfur-containing molecules has been examined on transition metals in order to try to understand the way in which they operate as hydrodesulfurization catalysts, and much of what has been learnt in the latter area will facilitate tribological understanding. [31][32][33][34][35][36] Another area in which the chemistry of sulfur-containing molecules is important, in particular its reaction with iron, is to understand and ultimately prevent the corrosion of oil pipelines by the sulfur contaminants present in oil.…”

Section: Introductionmentioning

confidence: 99%

Surface Chemistry and Extreme-Pressure Lubricant Properties of Dimethyl Disulfide

et al. 1998

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The growth kinetics of a film formed by the thermal decomposition of dimethyl disulfide on an iron foil are measured using a microbalance where the growth kinetics are parabolic (film thickness X varies with time as X 2 ∝ t) at high reaction temperatures and pressures, indicating that it is limited by diffusion through the film. The activation energy for this process is 54.5 ( 0.5 kcal/mol. The growth rate becomes linear as the reaction temperature and/or reactant pressure is lowered, indicating that, under these circumstances, the reaction rate is limited by thermal decomposition of dimethyl disulfide at the growing interface. The activation energy for thermal decomposition at the interface is found to be 37.6 ( 0.7 kcal/mol, and a half-order kinetics pressure dependence for the surface reaction rate is found consistent with a reaction limited by the rate of dimethyl disulfide dissociation. Analysis of the resulting film using Raman and X-ray photoelectron spectroscopies as well as X-ray diffraction reveal the formation of FeS, which may be slightly nonstoichiometric. This film is similar to that formed by methanethiol, suggesting that they may both initially form a surface thiolate species that further reacts to form FeS. The half-order reaction kinetics noted above are consistent with this. Measurement of dimethyl disulfide as an extreme-pressure (antiseizure) additive reveals a plateau at an applied load of ∼4000 N in the seizure load versus additive concentration curve. It has previously been suggested that the plateau corresponds to the load at which the interface reaches the melting point of the solid lubricant layer (in this case proposed to be FeS). Estimation of the interfacial temperature using a method developed previously yields an interfacial temperature of ∼1480 K, in good agreement with the melting point of FeS.

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Section: Introductionmentioning

confidence: 99%

Surface Chemistry and Extreme-Pressure Lubricant Properties of Dimethyl Disulfide

et al. 1998

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“…During this tribological test with the pentasulfide, the iron sulfide some authors suggest a better wear reduction with crystalline FeS because its hexagonal structure could facilitate shearing planes [18][19][20][21][22][23][24]. In our case, it is very difficult to make any correlation between the iron sulfide types and specific tribological behavior.…”

Section: Friction Tests Under Controlled Atmospherementioning

confidence: 47%

The effect of an organic pentasulfide EP additive in turning and milling operations

Minfray

Fromentin

Bierla

et al. 2014

Wear

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is an open access repository that collects the work of Arts et Métiers ParisTech researchers and makes it freely available over the web where possible. Abstract:Because a cutting fluid could be equally used for different cutting operations, this study reaction with sulfur compounds to produce iron sulfides. Because milling is a discontinuous cutting process, this lubrication mechanism is much more efficient than that observed in turning. Indeed, the tool faces are re-fed iron sulfides each time they leave the workpiece.

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“…The mechanism and mode of action of anti-friction, antiwear and E.P. additives have been extensively reported during the past several decades [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][30][31][32][33][34][35][36][37][38]. These studies fall into three distinct categories.…”

Section: Introductionmentioning

confidence: 99%

“…The suggested mechanism of action of these additives is considered to involve formation of simple inorganic or organic moieties comprising metal sulfides, phosphates, mercaptides and carboxylates [1,2,4,[9][10][11][12] as surface films which are supposed to be easily sheared or have slipplanes and defect structures causing reduction in wear and friction under various conditions of loads and speeds [15][16][17][18][19][20][21][22][23].…”

Section: Introductionmentioning

confidence: 99%

Anti wear and anti friction characteristics of tribochemical films of alkyl octa-decenoates and their derivatives

Chibber

Chaudhary

Tyagi

et al. 2005

Lubrication Science

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The wear, friction and film forming characteristic of ethyl octadecenoate and methyl 12-hydroxy ocatadecenoates, their thio and thiopyrophosphoro derivatives have been studied on HFRR friction and wear machine. The structural characteristics of chemisorbed films formed on the iron surfaces by these derivatives have been investigated using various analytical techniques such FT-IR, Microreflectance Absorption and Proton Magnetic Resonance. It has been inferred that these films are primarily organic in nature. The constituents of these films are hydroxy alkyl and aryl ethers, unsaturated and condensed ring hydroxy ketones, aromatic hydroxy quinones and highly condensed aromatic structures chemically linked to iron sufaces through hydroxy, oxy, thia, oxyphosphoro and thiophosphoro moieties forming chelated and coordinated complexes.The antiwear and antifriction characteristic of alkyl octadecenoates increase with increasing polar linkages in the alkyl ocatadecenoate backbone. This is primarily due to the increase in number of sites amenable to chemisorption on the surfaces and consequently their reactivity. The antiwear and antifriction characteristic of derivatives of ethyl octadecenoates are inferior to the corresponding 12-hydroxy methyl octadecenoates derivatives. This can be attributed to increased reactivity of 12-hydroxy methyl octadecenoates derivatives at the surfaces due to an additional hydroxyl moiety. The films formed are highly condensed ring aromatic layered structures coordinating to iron atoms of the surface particularly in case of thiopyrophosphoro derivatives of methyl 12-hydroxy octadecenoates. These films, as a consequence, provide lower wear and friction characteristics as compared to other types of organic films. These studies have led to much clear evidence of the intimate relationship between the chemical structure of the additives and their film forming characteristics.

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Effects of some chemical factors on film failure under EP conditions

Cited by 36 publications

References 10 publications

Surface Chemistry and Extreme-Pressure Lubricant Properties of Dimethyl Disulfide

Surface Chemistry and Extreme-Pressure Lubricant Properties of Dimethyl Disulfide

The effect of an organic pentasulfide EP additive in turning and milling operations

Anti wear and anti friction characteristics of tribochemical films of alkyl octa-decenoates and their derivatives

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