bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and tribological behaviour of phosphorus—nitrogen‐modified rape seed oils as biodegradable lubricant additives
Authors: Jian‐hua Fang , Bo‐shui Chen , Bin Zhang , Wei‐jiu Huang 
Published: July 2006

AbstractTwo types of phosphorus—nitrogen‐modified rape seed oils as biodegradable lubricant additives were synthesised and characterised by infrared spectroscopy. Their tribological properties in rape seed oil and in mineral oil were evaluated in a four‐ball tester. The morphologies of the worn surfaces were analysed by scanning electron microscopy. The results show that the modified rape seed oil additives improve the load‐carrying capacity and the antiwear and friction‐reducing properties of rape seed oil more than they do those of mineral oil. The inferred mechanism of lubrication is that a high‐strength adsorption film and/or tribochemical reaction film forms on the rubbing surfaces, due to the carrier effect of long‐chain rape seed oil molecules and to the high reaction activities of phosphorus and nitrogen and their synergism.
Total vegetable‐oil based greases prepared from castor oil
Authors: Dwivedi M. C. , Sapre Smita 
Published: July 2006

AbstractTotal vegetable oil greases are those in which both the lubricant and gellant are formed from vegetable oil. Vegetable oil may be used as a lubricant as such or, with appropriate structural modification, as an ester or alkylated ester. Total vegetable oil greases have the advantage of good biodegradability and conform to the requirements for high performance.Total vegetable‐oil based greases can be formed by mixing preformed soap and lubricant in the required proportions to form a grease with the desired properties. Alternatively, a grease can be formed from the same vegetable oil by simultaneous alcoholysis and saponification of the oil to form the lubricant and soap. The alkali used as a catalyst for the alcoholysis reaction serves as a reactant for the saponification reaction. The use of the appropriate proportion of oil, alcohol, and alkali will thus form a grease of the desired composition.A simultaneous reaction scheme to form sodium and lithium grease using castor oil has been studied. The alcoholysis reaction is separately studied for its kinetics, and the kinetics of the alcoholysis and saponification reaction are reported. Greases with 20% soap have been formed and their properties evaluated.
Performance of synthetic oils in the hydrodynamic regime ‐ II. Generalisation
Authors: Glavatskih Sergei B. , Larsson Roland 
Published: July 2006

AbstractIn Parti I the results of an extensive experimental investigation of the performance of environmentally adapted oils in the hydrodynamic regime were reported. Four oils were tested in a tilting‐pad thrust bearing for different combinations of load, shaft speed, and supply oil temperature. In this second part, details of a generalisation procedure are described. A number of parameters representing the physical properties of an oil, such as viscosity and viscosity‐temperature coefficient, are adopted. The influence of each of these parameters on minimum oil film thickness, maximum temperature rise, and bearing power loss is then analysed. It is shown that viscosity measured at the supply oil temperature is the most important parameter. The effects of the viscosity‐temperature coefficient and oil thermal conductivity are less pronounced and yet significant. It is also shown that it is not possible to select an optimum oil that yields maximised oil film thickness, minimised temperature rise, and minimised power loss at the same time.
Properties and applications of synthetic greases
Authors: Kimura Hiroshi , Onuki Yuji 
Published: July 2006

AbstractMineral oils are still predominant as base oils for lubricating greases, although increased numbers of greases have been developed with synthetic oils because of their good performance properties, including thermal/oxidation stability, low‐temperature fluidity, and plastics compatibility. Long life under high‐temperature conditions and good low‐temperature fluidity are required of greases used in bearings of engine electrical components. As many plastics are used in place of metals for the purpose of weight saving, synthetic hydrocarbon greases are used that do not have adverse effects on plastics. Various other special synthetic greases are also in use depending on specific requirements, such as conductivity and vacuum conditions. The properties and applications of various synthetic greases are discussed here.
The influence of engine oil on diesel exhaust emissions
Authors: Gligorijevic R. , Jevtic J. , Biresaw G. 
Published: July 2006

AbstractIncreasingly stringent emission legislation, together with the requirements for improved diesel engine performance, such as fuel economy, friction reduction, and extended drain intervals, have led to attention being focused on engine oil quality. The use of low‐friction engine oils can improve engine fuel efficiency and lead to a significant reduction of gaseous emissions. Therefore, engine oil is of importance when considering engine design parameters.This paper describes a study of the contribution of engine oil to diesel exhaust emissions. The investigations have shown that diesel engine particulate emissions as well as hydrocarbons and NOX emissions depend on the lubricant oil properties, in particular on the sulphur content, volatility, and metal content.
Synthetic polyurea extreme‐pressure greases
Authors: Singh T. , Bhan A. K. 
Published: July 2006

AbstractThis paper describes the preparation of synthetic polyurea greases and evaluates their performance. The polyurea greases were prepared in situ by reacting diisocyanate with monoamines and ethylene diamine in the presence of a synthetic base oil (polyalphaolefin). Two different extreme‐pressure (EP) additives blended with the prepared polyurea greases were evaluated for their EP activity in four‐ball and Timken tests. The additivated greases gave higher loads, and higher values of weld load in the four‐ball test as compared to the polyurea grease without additive. The blended greases were also found to pass rust, corrosion, oxidative stability, and shear stability tests. The topography of the wear‐scar surfaces was investigated using scanning electron microscopy.
Suitability of vegetable oils as industrial lubricants
Authors: Gerbig Y. , Ahmed S. I. ‐U. , Gerbig F. A. , Haefke H. 
Published: July 2006

AbstractThis paper reports on the application‐relevant properties of sixteen commercially available vegetable oils tested without additives in accordance with established standards. Their performance was compared with each other and with that of mineral oil and synthetic esters. The basic characteristics of all the oils (density, viscosity, pour point, cloud point, flash point and fire point) were initially determined. A chemical analysis of the vegetable oils was carried out to determine the acid value, saponification and iodine numbers. Additionally, the oxidative stability of all the oils was tested. The tribological performance, lubrication, and wear protection of the oils were judged under abrasive as well as adhesive conditions. The comparative study of the test vegetable oils showed great differences in the properties of the oils. All the vegetable oils tested revealed weak points during testing, including rape seed and castor oils, which have established uses in industry. This study shows that certain vegetable oils, such as sesame oil and wheatgerm oil, may have potential for use in selected technical applications. The mineral oil and synthetic esters showed markedly superior performance when tested under adhesive conditions, but comparable behaviour to the other oils under abrasive conditions.
Interaction between zinc dialkyldithiophosphate and amine
Authors: Shiomi M. , Tokashiki M. , Tomizawa H. , Kuribayashi T. 
Published: July 2006

AbstractThis paper reports work on complex formation from ZDP and various aliphatic amines, and their equilibrium states in oil, adsorptivities and antiwear properties are investigated. Complex formation from ZDP and amine was proven by isolation and identification of solid crystals, and various complexes were found from mono‐ and diamines. The complex from monoamine has lower adsorptivity than free ZDP, while the poorer adsorptivity of ZDP/monoamine complex makes its antiwear property worse.
Raman microspectroscopy of a working elastohydrodynamic contact
Authors: Gardiner Derek J. , Baird Ewan M. , Craggs Carolyn , Dare‐Edwards Martin P. , Bell John C. 
Published: July 2006

AbstractThe design and operation of two closely‐related pieces of apparatus which allow the acquisition of Raman spectra from lubricant fluids ‘in lubro’ in an elastohydrodynamic contact are reported. Spectroscopic sensitivity was not sufficient to allow a detailed structural interpretation of the spectra under these extreme conditions. However, the systems have been used in a novel way to obtain profiles and maps of the pressure distribution, as experienced by the fluid in the working elastohydrodynamic contact.
Numerical calculations of the pressure spike in elastohydrodynamic lubrication
Authors: Venner C. H. , Napel W. E. Ten 
Published: July 2006

AbstractThe application of advanced multilevel techniques to the solution of the EHL line contact problem has resulted in a multilevel solver of complexity O(n In n). The reduction in computing time thus obtained enables the use of large numbers of nodes and allows detailed study of the pressure spike. Both occurrence and height of the spike as a function of the governing parameters were studied. The parameter range where a pressure spike can be expected, and the results of spike height calculations, are presented.
Effects of NOx on liquid phase oxidation and inhibition at elevated temperatures
Authors: Johnson M. D. , Korcek S. 
Published: July 2006

AbstractNitrogen oxides (NOx =NO2 +NO) play a role in degradation of lubricating oils in internal combustion engines. Interactions of NOx with fuel derived species have been shown to lead to varnish and deposit formation. Mechanisms of interactions of NOx with additive and base oil components have not, however, been investigated in detail. The present work describes investigations of the effects of NO2 on oxidation processes and the fate of NOx in a model lubricant system. NO2 acts as a free radical initiator which accelerates the initial rate of uninhibited hydrocarbon oxidation and increases the rate of antioxidant consumption in inhibited systems. NOx consumption increases after the end of the inhibition period. In addition, NO2 and NO react with oxidation intermediates or products in a complex series of reactions which can include direct reaction with antioxidants, formation of nitro‐oxidation products, conversion of NO2 to NO and regeneration of NO2 from NO. The significance of results obtained in this study with respect to mechanisms of oil degradation is discussed.
Antiwear properties of complex compounds of Sn(II) and Sn(IV) in lubrication of a bronze‐steel contact
Authors: Ozimina D. , Kajdas C. 
Published: July 2006

AbstractThe wear characteristics of metal‐organic chelate additives containing tin bonded to aliphatic dicarboxylic acids were investigated on a reciprocating motion test machine in lubrication of a steel‐bronze contact. It was found that both the valence state of the tin and the chain lengths of the dicarboxylic acids affected the wear results. All the compounds reduce wear effectively and, at pressures below 1.76 MPa, they assure zero ZDTP and SnDTP additives in the steel‐steel concentrated contact using the standard four‐ball machine.
A study of the antiwear action mechanism of alkoxy aluminium in lubricating oil
Authors: Dong J. , Chen G. , Luo F. 
Published: July 2006

AbstractAluminium is situated beneath boron in the same group of the periodic table. As borate is a good antiwear agent for lubricating oils, it is possible that aluminium compounds maybe possess antiwear properties similar to borate. After testing seven alkoxy aluminium compounds, the results support this assumption. The most efficient compound is triethoxy aluminium. When 2% mass of triethoxy aluminium is added to ISO VG 68 oil, the load wear index of a four‐ball machine increases from 219 N to 519 N and the weld point from 1568 N to 4900 N. This compound also exhibits good corrosion protection property. In the present work, after steel balls of a four‐ball machine were run in aluminium‐containing oil, the wear scars were analysed by scanning electron microscope and X‐ray energy dispersion analysis. The main compositions discovered on the scar surface were 5.7–48.3 atom % of iron, 4.4–11.2 atom % of aluminium, 37.1–59.1 atom % of oxygen, 8.7–23.5 atom % of carbon, and 0.3–1.1 atom % of chromium, under 3087 N–39 200 N of axial loads. When the loads are lower than 2450 N, the contents of oxygen are almost equal to zero and the contents of iron increase to 68.6–93.8 atom %. Based on the results of surface analysis and using thermodynamic principles, an antiwear action mechanism for triethoxy aluminium is suggested: under low loads, the weaker bond C‐C (350 KJ /mol) is broken, and the broken fragments may form polymer film during friction processes. As the loads increase, the stronger bond Al‐O (484.5 KJ /mol) is broken to create active aluminium and oxygen. The oxygen reacts with aluminium and iron to form a complicated solid solution containing AlxOY, FExOy on the surface. This complicated surface layer raises the weld point of the steel balls.
Some observations on the role of oxygen in lubricated wear
Authors: Willermet P. A. , Kandah S. K. 
Published: July 2006

AbstractThe role of oxygen in lubricated wear is discussed. Previous studies have shown that at low concentrations, oxygen can reduce wear, but at higher concentrations, it can increase wear. The situation is complicated by ZDTP antioxidants. The present paper reports experimental work aimed at elucidating the role of hydroperoxides ‐ whether they participate in the formation of wear‐resistant oxide films, if they (or peroxy radicals) are the main source of oxygen, and whether ZDTP‐hydroperoxide interactions in the wear zone are important in controlling wear.
The effect of molecular structure of n‐containing heterocyclic compounds on their wear properties
Authors: Ren T. , Liu W. , Xue Q. , Wang H. 
Published: July 2006

AbstractThe friction and wear properties of N‐containing heterocyclic compounds (indole, indazole and benzotriazole), which have the same cyclic structure except for the number of N atoms, added to alkylbenzene and to a mixture of liquid paraffin with 2 % wt succinimide dispersant were evaluated using a four‐ball machine. The N‐hexadecanoylindazole and N‐hexadecanoylbenzotriazole were synthesised, and their friction and wear properties in liquid paraffin were also evaluated. X‐ray photoelectron spectroscopy (XPS) was used to examine the binding energy of N1s on the rubbed surface. The effect of the presence of a lone electron pair of nitrogens in the compounds on antiwear property is discussed using the theory of molecular orbits.
An investigation of the effectiveness of antifriction additives in motor oils by laboratory methods and engine tests
Authors: Arabyan S. G. , Holomonov I. A. , Karaulov A. K. , Vipper A. B. 
Published: July 2006

AbstractThe antifriction properties of motor oils with different additives (oil soluble metal‐containing compounds, molybdenum disulphide and graphite dispersions, and ashless additives) were investigated by means of laboratory methods. The influence of additive concentration on their effectiveness is evaluated. The effect of the action of antifriction additives (friction modifiers) depends on the base oil and motor oil additive packages. The results of experiments are analysed using Auger spectroscopy. A mechanism of action of different types of friction modifiers based on analysis of the experimental data is proposed. Diesel engine tests of motor oils with antifriction additives were used to show the influence of these additives on fuel consumption. The results of engine tests with oils with different additives, and tests conducted on laboratory friction‐machines, are compared. A description of the laboratory methods and engine test methods used, as well as recommendations for their practical use in evaluating antifriction properties of motor oil additives, is given.
Characteristic effects of DDC lubrication
Authors: Tonder K. 
Published: July 2006

AbstractThis paper discusses deep disconnected cavities (DDC), a concept first introduced by the author. Disconnected shallow cavities or pockets have been treated by other authors, but the consequences of the extreme depths involved with DDC have not been recognised. The introductory paper established the existence of DDC effects. The latter are partly expressible as a slightly modified Reynolds equation, in which the film thickness function refers to the local minimum rather than the local mean customary in roughness analysis. In addition, the equation involves modifying factors which are independent of film thickness and other aspects of the macro‐geometry of the bearing, generating what may be interpreted as effective viscosities. The present paper establishes, by numerical studies, more exact expressions for the effective viscosities for a certain class of cavity geometry and distribution. The interaction of macro‐ and micro‐geometry is studied, showing that the optimisation of the cavity distribution depends on the macro‐geometry of the bearing. It is further shown, by a combination of analytical and numerical means, that the minimum frictional coefficient obtainable for a DDC bearing is that of its smooth counterpart when the two are running at the same minimum film thickness. If the two are lubricated by the same fluid and take the same load, a well‐designed DDC bearing will have a lower coefficient of friction than a similar smooth one.
The synergistic effects of EP and AW additives with a sulphurised steel surface under boundary lubrication
Authors: Ma Yan‐Sheng , Liu Jia‐Jun , Zheng Lin‐Qing , Wei Dan‐Ping , Wang Ru‐Lin , Zhang Xu‐Shou , Liu Hong 
Published: July 2006

AbstractIn this paper the synergistic effect on tribological behaviour of two additives, sulphurised olefin and tricresyl phosphate, in paraffin oil, and 1045 steel, treated by sulphurisation, was studied on a ball‐on‐disc test machine. An excellent load‐bearing capacity was obtained by the combination of sulphurisation and the lubricant paraffin+sulphurised olefin. The mechanism of this synergistic effect is discussed, based on micro‐analysis of the surface film by AES and XPS.
Antifriction action of lubricant additives
Authors: Vipper A. B. , Bartz W. , Karaulov A. K. , Mischuk O. A. , Lukinyuk M. Yu 
Published: July 2006

AbstractThe influence of antifriction additives for engine oils on fuel economy in gasoline engines has encouraged an interest in research into their action mechanisms. The influence of additives of different types on the antifriction properties of engine oils has now been investigated; additives have been discovered which effectively increase thermal stability of the lubricating layers and decrease friction coefficient, even at high temperatures.The structure and composition of the surface layers of friction pairs have been studied with Auger electron spectroscopy. The inter‐relationship between the effectiveness of the antifriction action of the additives and their influence on the thickness and the composition of the surface layers has been ascertained. The most effective antifriction action was obtained where the thickness of the surface layers was reduced within certain limits, and where there was an optimisation of the oxygen and sulphur content. Certain regularities were established, since they were noticed while testing antioxidant, antiwear, antifriction, and detergent additives of different composition.
The effect of lubricants on deep drawability of zinc‐coated steel sheets
Authors: Muraki Masayoshi , Ide Hideo , Tagawa Kazuo , Nakamura Tamotsu 
Published: July 2006

AbstractThe effect of lubricants on deep drawability was studied for two types of zinc‐coated steel sheets on a high‐speed deep‐drawing machine. The drawability of galvannealed steel sheet, GA, at low speeds is significantly improved by friction modifiers, due to reduction in frictional forces around the die radius. In contrast to the results for GA, double layered steel, GAE, which has an Fe‐rich alloy coating on the top, and is superior to GA in terms of drawability, is insensitive to changes in the additives. This is mainly because the hardness of the upper coating layer of GAE decreases frictional resistance through a decline in the boundary contact area.
The hydrolytic stability of borates used as oil additives
Authors: Junbin Yao , Junxiu Dong 
Published: July 2006

AbstractEleven borate ester compounds were synthesised and their hy‐drolytic stabilities were compared. The results indicated that the hydrolysis problem of borate esters can be solved by introducing N, N‐dialkylamino‐ethanol with alkyl groups containing more than or equal to 4 carbon atoms in the esters. It was believed that the formation of a stable five‐member ring structure in molecules involving coordination of the nitrogen atom with boron contributes substantially to the resistance to hydrolysis of such compounds.
Elastohydrodynamics of lip seals
Authors: Salant Richard F. , Flaherty Andrew L. 
Published: July 2006

AbstractA numerical elastohydrodynamic analysis of a rotary lip seal with microundulations reveals that the undulation pattern plays a central role in the operation of the seal. The undulations hydrodynamically generate elevated pressures within the lubricating film, providing load support, and deform in such a manner as to produce reverse pumping. The reverse pumping counteracts the flow induced by the sealed pressure, and thereby prevents leakage through the seal.See p. 25 for the nomenclature.
Structure—performance relationships of viscosity index improvers: I microstructural determination of olefin copolymers by NMR spectroscopy
Authors: Kapur G. S. , Sarpal A. S. , Mazumdar S. K. , Jain S. K. , Srivastava S. P. , Bhatnagar A. K. 
Published: July 2006

AbstractFive commercial olefin copolymer (OCP) viscosity index (VI) improvers have been characterised at the molecular level. The copolymer compositions have been determined using 1H and 13C‐NMR spectroscopy. The microstructural parameters, such as comonomer sequence distribution, number average sequence lengths and run number, have been determined by 13C‐NMR spectroscopy. NMR spectral editing techniques, e.g. Distortionless Enhancement via Polarisation Transfer (DEPT) have been used for peak assignments. This analytical approach aims at correlating the microstructural parameters with the physical properties and performance of these VI improvers, to be communicated later.
The contribution of new dispersant mixed polymers to the economy of engine oils
Authors: Pennewiß H. , Auschra C. 
Published: July 2006

AbstractMixed polymers have been concentrated to produce highly concentrated VI improvers based on polyalkyl methacrylates (PAMA) and olefin copolymers (OCP). Because of their liquid form and special viscosity/temperature relationship, these concentrates can be stored, shipped and processed at comparatively low temperatures. This, in combination with a high specific activity, favours the economic manufacture of multigrade oils.In the VW elastomer compatibility test, the new dispersant mixed polymers (d‐MP2) show absolutely neutral behaviour towards fluoroelastomers. In gasoline as well as in diesel engines they contribute noticeably to the dispersant potential, thus making it easier to comply with the requirements for API SH. Moreover, bench and road tests have revealed a major reduction of engine wear. The effect of different dispersant groups is compared by way of a simple laboratory test and an attempt is made at corroborating a hypothesis on wear reduction.