bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of a high performance railroad diesel engine oil for improved oil consumption control
Authors: Mazumdar S. K. , Tiwari O. P. , Chaubey D. M. , Rao A. M. , Srivastava S. P. , Bhatnagar A. K. 
Published: July 2006

AbstractHigh output railroad diesel engines today require high‐performance crankcase lubricants, not only for extending drain intervals, but also for economising by lowering oil consumption. Although the importance of engine design in controlling oil consumption has been recognised for quite some time by the oil and railroad industries, another approach has been to reduce oil consumption by effective design of crankcase lubricants. This paper reports the development of a high‐performance railroad diesel engine oil with superior detergency, dispersancy, oxidation and thermal stability characteristics vis‐à‐vis oils formulated with the latest generation packages. The same oil has also given reduced oil consumption in the Petter AV‐1 performance engine test. Multigrading this formulation has resulted in further reduction in oil consumption.
Extreme‐pressure behaviour of lubricated ceramic/steel couples
Authors: Bartelt G. , Becker R. , Zimmermann B. 
Published: July 2006

AbstractThe friction and wear behaviour of lubricated ceramic/steel couples was studied, for increasing loads, with a four‐ball tester. For the steel spheres of ceramic/steel couples, a transition point to severe wear was observed, which occurred at loads four to five times higher than the transition for the corresponding steel/steel couple. The extreme‐pressure behaviour for conditions of lubrication with pure hexadecane is compared with the results for lubrication with solutions containing zinc di‐n‐butyl dithiophosphate or zinc di‐sec‐butyl dithiophosphate.
A study of the rheological behaviour of multigrade oils
Authors: Hassanean M. H. M. , Bartz W. J. , Abou Naga H. H. El 
Published: July 2006

AbstractThe rheological behaviour of four blends of multigrade oils containing different commercial viscosity index improvers has been studied for increasing shear rate and temperature.Polyalkylmethacrylate has been found to demonstrate different behaviour to styrene‐isoprene, styrene‐butadiene and ethylene‐propylene copolymers. Oil blends for all these hydrocarbon copolymers have shown non‐Newtonian behaviour with increasing shear rate (0 to 35,000 s−1) at low and moderate temperatures (−15 to 40°C), i.e. their viscosities were subject to a significant decrease, while the viscosity of the polyalkyl‐methacrylate blend showed a limited decrease. With increasing shear rate at high temperature (100°C), all the formulated blends behaved as Newtonian fluids, i.e. with nearly constant viscosities.Increasing shear rate can also change the behaviour of some hydrocarbon copolymers from thickeners to viscosity index improvers.
Antiwear synergism of borates and cadmium diamyldithiocarbamate
Authors: Junbin Yao 
Published: July 2006

AbstractCertain combinations of an oil‐soluble cadmium compound, e.g., cadmium diamyldithiocarbamate, with organo‐borates, either sulphurised or nonsulphurised, give better antiwear performance than do the individual components. A synergistic mechanism is postulated, in which boron atoms with vacant p orbitals catalyse triboreduction of cadmium on rubbing surfaces, producing elemental cadmium. The cadmium deposits on, and alloys with, the metal surface to protect the substrate against wear.
Friction and wear behaviour of liquid paraffin containing an S‐P type additive and amine
Authors: Weimin Liu , Canzhu Gao , Pingyu Zhang , Qunji Xue 
Published: July 2006

AbstractSulphurised olefin (SO) and dibutyl phosphite (DBP) are two popular antiwear and extreme‐pressure additives for gear oils. Investigation of the effects of the weight ratio of SO to DBP in liquid paraffin, and the effects of dodecyl amine, on the friction and antiwear properties of oil, were conducted with a four‐ball wear tester. The chemical composition of the film, formed was examined using X‐ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES) and reflecting infrared spectro‐scopic (IR) microscopy.The four‐ball test results indicate that the weight ratio of SO to DBP affects the friction and wear behaviour of the oil and, with a weight ratio of SO to DBP of 20:1, a stable friction coefficient, and the smallest wear scar, were observed. Wear tests also showed that dodecyl amine improves or reduces the antiwear ability of the oil at certain concentrations. AES profile analyses demonstrate a thick boundary film formed on the rubbed surface with the weight ratio of SO to DBP at 20:1. Both AES and IR results indicate that the addition of dodecyl amine to an S‐P type oil results in competitive adsorption, and hinders the reaction of SO and DBP with the steel surfaces.
Expressions for coefficients of electrorheological fluid dampers
Authors: Kohl James G. , Tichy John A. 
Published: July 2006

AbstractUseful expressions are developed for the damping coefficient of two types of viscous dampers that contain electrorheological (ER) fluids. The damping action in the first type occurs in flow between stationary parallel plates; the second type has annular flow between two stationary concentric cylinders. For ER fluid control, an electric field is applied across the gap in which the fluid flow occurs. The solution for the concentric cylinder damper is based on a thin gap approximation. These solutions may facilitate solving mechanical systems problems, using ER fluids, and demonstrate the controllability of ER dampers.
The tribological properties of diethylammonium lanthanide tetrakis (diethyldithiocarbamate) in lubricating oil
Authors: Zefu Zhang , Weimin Liu , Qunji Xue , Tianhui Ren , Wei Wang 
Published: July 2006

AbstractThe synthesis of four oil‐soluble rare earth complexes of diethylammonium lanthanide tetrakis(diethyldithiocarbamate) (ReDTC) is described. The tribological properties of these rare earth complexes as additives in lubricating oil have been evaluated using a four‐ball machine. The results show that these novel complexes have excellent extreme‐pressure properties and selective antiwear properties in lubricating oil. The action mechanism of the rare earth complexes as additives in lubricating oil was investigated using X‐ray photoelectron spectroscopy (XPS).
Friction and wear of grey cast iron against Si3N4 in emulsion and water
Authors: Liang Fang , Songhua Si , Yimin Gao , Qingde Zhou 
Published: July 2006

AbstractFriction and wear tests of Si3N4 against cast iron were carried out using a ring‐on‐block tester lubricated by emulsion. To provide a comparison with emulsion, distilled water was also used as a lubricant in the tests. The results show that emulsion can prevent the formation of an SiO2·2H2O film on the iron surface. Although the friction coefficient of Si3N4/ iron pairs in emulsion is much greater than in distilled water, the wear of Si3N4 in emulsion is less.
Hydrodynamic lubrication of the ironing process
Authors: Mahdavian S. M. , He D. 
Published: July 2006

AbstractA theoretical model is presented to calculate the lubricant film thickness in an unsteady hydrodynamic lubrication of cup‐shaped products to be formed by the ironing process. The model covers the development of hydrodynamic lubrication in various phases of the ironing process. The model provides equations for estimating the lubricant film thickness for each phase.Experiments were conducted to study the effect of lubricant viscosity on die expansion and punch force in making cup‐shaped products by the ironing process. It was found that the die expansion varied between unlubricated and lubricated cups and depended on the lubricant viscosity. The film thickness was estimated from the difference between the increased die/punch clearance, which was calculated from the expansion, and the lubricated cup wall thickness. The theoretical film thickness was compared with the estimated film thickness based on the die expansion measurement.
Evaluation of surface fatigue performance of gear oils
Authors: Hong H.‐S. , Huston M. E. , O'Connor B. M. , Stadnyk N. M. 
Published: July 2006

AbstractThe effect of additive chemistry on the surface fatigue of gears was investigated using an FZG gear tester and fluids based on an API GL‐5 grade gear oil. Surface fatigue lives were determined as a function of load and additive chemistry. At 1.52 GPa, the removal of the primary extreme pressure (EP) additive from the fully formulated gear oil decreased the fatigue life of gears slightly (4%). However, the removal of the primary antiwear (AW) additive decreased the fatigue life of gears significantly (83%). At 1.86 GPa, the removal of the EP additive from the fully formulated gear oil decreased the gear fatigue life by 27%. However, the removal of the primary AW additive decreased the fatigue life of gears significantly (75%). Micro‐pitting was the dominant surface morphology in the dedendum of the gears tested with two oils at load stage eleven: one using the complete additive package, and a second where the EP additive had been removed. However, spalling was the primary failure mode of gears tested without an AW additive, independent of whether an EP agent was present. Surface analysis of the pinion gears showed the formation of a mixed phosphate/phosphite—oxide layer on the surface of gears tested with fluids containing an AW additive. Formation of this layer seems to be the key to a long fatigue life.
Friction and wear behaviour of an Al‐Si alloy against steel lubricated with N‐ and O‐containing organic compounds
Authors: Weimin Liu , Yanhong Hu , Zhiming He , Pingyu Zhang , Qunji Xue 
Published: July 2006

AbstractThe friction and wear properties of an Al‐Si alloy against AISI 52100 steel were investigated with a block‐on‐ring wear tester lubricated with a liquid paraffin base oil containing organic additive compounds, such as ethylenediamine, ethyleneglycol, ethanolamine, and N,N‐dibutylethanolamine. The boundary film formed on the rubbed surface of the Al‐Si alloy was then examined using FT‐IR microscopy and XPS.The friction and wear tests revealed that ethylenediamine, ethanolamine and N,N‐dibutylethanolamine additives provide good lubrication in the Al‐Si alloy‐on‐steel system, especially N,N‐dibutylethanolamine. FT‐IR microscopy and XPS revealed the possible formation of a chemically stable five‐ring complex of aluminium or silicon with diamine and ethanolamine.
Variation and recovery of resistivity of industrial greases — an experimental investigation
Authors: Prashad Har 
Published: July 2006

AbstractIn the present work, variation in the resistivity of different greases with time in static conditions, under the influence of applied potential drops, is established. The change in resistivity and physico‐chemical characteristics of the greases in electric fields, and recovery of the resistivity within the test period in the absence of applied potential drop, have been found.The properties of the greases are compared, and their correlation with resistivity is analysed.The paper also gives the results of analysis using an SRV tester, IR spectra, chemical analysis and spectrophotometry, of changes that occurred periodically in the greases, normally used in non‐insulated rolling‐element bearings in the presence of a potential drop across the inner and outer races. The paper highlights the behaviour and mechanism of the process of bearing failure under electric fields.
Highly reactive polyisobutene as a component of a new generation of lubricant and fuel additives
Authors: Mach H. , Rath P. 
Published: July 2006

AbstractThis paper describes the synthesis of highly reactive polyisobutene (PIB), a special type of PIB used as a component in the production of lubricant and fuel additives. The reactivity and the chemical structure are described in detail, in relation to the nature of the product and its uses as an additive component.
Synthesis of new additives for lubricating oils and industrial greases
Authors: Dinoiu Vasile , Florescu Danilian , Stanescu Chiriaca 
Published: July 2006

AbstractAshless antiwear, antioxidant, and extreme‐pressure additives based on hydrocarbon‐soluble metallic complexes of thio‐bis‐phenols, their method of preparation, and their use as additives in oils and industrial greases, have been studied. This paper presents a description of their derivation and performance.
A simplified calculus method for a grease‐lubricated Rayleigh step bearing
Authors: Radulescu A. V. , Vasiliu F. 
Published: July 2006

AbstractThe paper presents a simplified method for the analytical calculus of a grease‐lubricated infinitely large Rayleigh step bearing.The principal problem of the grease flow through a Rayleigh step bearing is the shape of the stagnant core in the step region. This shape is determined using Navier‐Stokes equations resolved by the finite method element. The theoretical results are compared with those obtained experimentally by visualisation of the grease flow using the reflecting tracer method. The conclusion of the simplified method is that a Rayleigh step bearing lubricated with grease is equivalent to one lubricated with oil, but with a different configuration of the convergent interstice.
Low‐temperature rheology of engine lubricants subjected to mechanical shear: Viscosity modifier effects
Authors: Covitch Michael J. , Weiss Joseph , Kreutzer Ingo M. 
Published: July 2006

AbstractIt is well known1–5 that the viscosity of crankcase lubricants decreases in the early stages of use due to shearing of the viscosity modifier (VM) and, depending upon the type of service, fuel dilution. This paper examines the effects of VM chemistry on the shearing process, and particularly how both high‐temperature and low‐temperature viscosities can change as a result of mechanical shear in the Kurt Orbahn injector test and during a passenger car fleet test. Commercial olefin copolymer, styrene/butadiene, styrene/isoprene, and radial isoprene polymers were included in this study, as a way of representing the major VM chemistries used in motor oils throughout the world. The rate of change of kinematic and high‐temperature, high‐shear‐rate viscosity with time, as well as low‐temperature cranking and pumping viscosity changes, were found to be characteristic of particular VM chemistries.
The preparation and tribology of spherical nanometric particles of diantimony trioxide SbOx(OH)y
Authors: Dong J. X. , Hu Z. S. , Chen G. X. 
Published: July 2006

AbstractSpherical diantimony trioxide SbOx(OH)y with a particle size of 30–70 nm has been prepared using a technique known as ‘ethanol supercritical fluid drying’. The tribological properties of an SN500 oil containing these nanometric particles were measured using a four‐ball and block‐on‐ring tribotester. The wear resistance and load‐carrying capacity of the oil were higher, and its friction coefficient lower, than that of the base oil. An excessive nanometric particles content was found to be disadvantageous to the load‐carrying capacity of the oil. The spherical nanometric diantimony trioxide appears to work by deposition on the rubbing surfaces and through the rolling action of the spherical particles.
The effect of viscosity index improvers on the determination of metal content in new and used multigrade oils
Authors: Mohamed M. M. , El Naga H. H. Abou , El Meneir M. F. 
Published: July 2006

AbstractAtomic absorption spectroscopy is widely used to determine the metal content, especially of zinc, calcium, iron, and copper, in new and used multigrade oils. Many methods involve dilution of the sample with kerosene followed by aspiration into the atomic absorption. However, results indicate that such methods are subject to matrix interferences, the factors most influencing such interferences being: the concentration of viscosity index improver incorporated into the multigrade oil formulations; chemical structure of the viscosity index improver; the molecular weight of the viscosity index improvers; and the viscosity of the solvent used.Regression equations for some commercial viscosity index improvers have been established, to permit correction of the concentrations of zinc, calcium, iron and copper measured in new and used multigrade oils.
The influence of chemical composition on the pour‐point depressant properties of methacrylate copolymers used as additives for lubricating oils
Authors: Florea M. , Catrinoiu Doina , Luca Paul , Balliu S. 
Published: July 2006

AbstractMethacrylate polymers are much used as additives in lubricating oils, as pour‐point depressants and viscosity index improvers. Although the mechanism of such pour‐point depression is still controversial, it is thought to be related to the length of the alkyl side chains of the polymethacrylates, and to the nature of the base oil. In this paper, work is reported on: (a) the depressant activity of polymethacrylate copolymers in relation to the content of short alkyl methacrylates and styrene, and the average side‐chain length of the basic methacrylate constituents; (b) the pour point of the base stock; and (c) the additive concentration.
Maximum oil film pressure and temperature of two‐iobe journal bearings with different bush profiles
Authors: Strzelecki Stanisław 
Published: July 2006

AbstractThis paper presents data on the maximum oil film pressure and temperature of two‐lobe journal bearings with different bore profiles. A bearing with a cylindrical non‐continuous bore profile, and another with a pericycloid continuous profile have been evaluated. For an assumed relative length of the bearings, and parallel orientation of the journal and bearing axes, the minimum values of oil film thickness, maximum pressure values, and temperatures of the oil film have been determined. The calculations were carried out on the assumption of an adiabatic oil film and a static equilibrium position of the journal.
Synthesis of some additives from upgraded petroleum residues of lubricant oil refineries
Authors: Mohamed M. M. , Naga H. H. Abou El , Anis A. 
Published: July 2006

AbstractAromatic extract residues occur as by‐products in petroleum refineries, through the process of refining lubricant oil. These residues are considered as having low economic value, and their disposal may even cause problems for the refineries. The present work looks at upgrading these residues by using them to synthesise different petroleum additives, e.g., antioxidants, ashless dispersants, pour‐point depressants, and flow improvers for lubricating crankcase oils and for fuels. The antioxidants were synthesised by reacting mono‐aromatics with phosphorus pentasulphide (P2S5) in the presence of zinc oxide (ZnO). Ashless dispersant additives were synthesised by reacting alkylated mono‐aromatics (using chlorinated paraffin wax as an alkylating agent) with formaldehyde solution (37%) in the presence of polyisobutylene succinimide. Fuel pour‐point depressants and flow improvers can be synthesised by acylating di‐aromatics via a Friedel‐Crafts reaction. Comparative evaluation of the synthesised products with commercial additives showed them to have good comparative performance properties.
The effect of mechanical stress on four viscosity improver polymers
Authors: Bezot P. , Hesse‐Bezot C. , Faure D. , Calvez J. C. 
Published: July 2006

AbstractThe effect of a Bosch injector on the mass distribution function of four viscosity improver (VI) polymers has been studied. Two of these, hydrogenated styrene—isoprene (HSI) and hydrogenated styrene—butadiene (HSB), are di‐block polymers, whereas the others are either comb‐like, polyalkyl methacrylate (PMA), or linear, olefin copolymer (OCP).Measurements were performed by light scattering and viscometric techniques before and after application of mechanical stress. Only slight modifications in the physical properties were detected for HSB and HSI, which can be explained by their micellar behaviour. Conversely, a large variation in mean size and viscometric properties was observed for PMA and OCP. Finally, a model is proposed which links the variation of the mass distribution function to the intrinsic viscosity loss.
A comparative study of the thermal behaviour of circular and non‐circular journal bearings
Authors: Sehgal Rakesh , Swamy K. N. S. , Athre K. , Biswas S. 
Published: July 2006

AbstractA comparative theoretical analysis of three types of hydrodynamic journal bearing configuration, namely, circular, axial groove, and off‐set halves, is presented for the thermohydro‐dynamic case. The two‐dimensional solutions of the Reynolds and energy equations take account of the variation in lubricant viscosity with temperature. The theoretical models also consider heat conduction through the bush, but do not take account of heat transfer through the shaft or recirculation of oil. It is observed that the off‐set bearing runs cooler than an equivalent circular bearing with axial grooves.
Viscometric studies of oil‐in‐water mixtures
Authors: Nabhan M. B. 
Published: July 2006

AbstractAn interesting property of oil‐in‐water (o/w) mixtures that has attracted the attention of tribologists, is their ability to form thicker hydrodynamic films than those expected from their apparent rheological properties. In concentrated contacts lubricated with o/w mixtures the oil phase is believed to separate out on the metal surface.To study this phenomenon, experiments have been conducted on a specially designed viscometer rig, with different concentrations of o/w mixtures used as a lubricant. The rig was composed of a metal tube with a straight and parallel cylindrically ground bore and metal ‘droppers’ of similar tolerances. The droppers can descend in the tube filled with the o/w mixture at a uniform velocity; the radial clearances between the descending droppers and the tube are very small.It was found that, even at oil concentrations as low as a few per cent, higher viscosity values for o/w mixtures are obtained in concentrated contacts, in relation to their bulk values. These results can be quantitatively explained in a theory which assumes trapping of oil particles between metal surfaces, correlated to the displacement energy at the oil—water—metal boundaries.
A study of the purification of used engine oils with a montmorillonitic clay
Authors: Mohellebi F. , Bouchekhou A. , Harbi N. , Hadjoudj F. T. , Chitour C. E. 
Published: July 2006

AbstractThe present paper looks at percolation, a recycling technique for engine oils that is non‐polluting and dispenses with the use of acid. The technique employs Algerian bentonite as a complementary purifier of used SAE 20W–50 engine oils which have first been dehydrated and had the light hydrocarbons (gasoline) removed. In order to understand the nature of the used oil, the characteristics of an oil in service were closely monitored over 7000 km. Various tests were performed on the bentonite to find the most satisfactory form of clay filtration bed. The species retained by the beds were analysed.