bluuebunny/crossref_metadata_2025_split huggingface dataset:
A statistical model describing wear traces in three‐body abrasion
Authors: Fang Liang , Zhou Qingde 
Published: July 2006

AbstractCutting wear is a mechanism by which material is removed through three‐body abrasion. In the present paper, a statistical model describing the wear traces on a worn surface is proposed for three‐body abrasion, to estimate cutting wear as a proportion of the total wear of the test materials. Using this model, a statistical analysis of the traces on the worn surface was made after short‐travel, three‐body abrasion tests. The results showed that cutting was not a great proportion of the total wear of the test materials under the conditions of three‐body abrasion.
Development of laboratory tests to predict the lubricity properties of diesel fuels and their application to the development of highly refined diesel fuels
Authors: Bovington C. , Caprotti R. , Meyer K. , Spikes H. A. 
Published: July 2006

AbstractIn the last few years there has been an increasing requirement for the provision of environmentally benign diesel fuels. However, the introduction of such fuels into service has been associated with high levels of field failure of rotary distribution fuel pumps due to wear. This is because the refining processes necessary to produce ecologically acceptable fuels result in greatly reduced levels of sulphur compounds, aromatics, and polar material, many of which are potential lubricity agents.This paper describes the development of bench test methods to evaluate diesel fuel lubricity and thus enable the identification of appropriate ‘solutions’.It has been found that the key to obtaining good correlation between field experience and bench tests is (1) to reproduce the thermal conditions present in operating pump contacts and (2) to ensure that the same mechanisms of wear operate in the bench test as in the pump environment. The physical and chemical processes involved in the lubrication of fuel pumps and the influence of temperature on these processes are outlined.As a result of the work described in this paper, effective additive solutions have been discovered for controlling the failure of diesel fuel pumps in the field and a provisional ISO (ISO/TC 22 / SC 7 M595: ‘Diesel engines ‐ diesel fuel ‐ performance requirement and test method for assessing fuel lubricity’) and CEC test method for assessing diesel fuel lubricity has also been developed.
The effect of surface chemistry in lubrication on the tribological behaviour of steel rollers under rolling‐sliding contacts
Authors: Lin Jen Fin , Chou Chau Chang , Chen San Tong 
Published: July 2006

AbstractExperiments were carried out on a wear test machine utilising a gearcam adapter to simulate line‐contact lubrication. Due to the formation of a surface adsorption layer on the steel substrate, the tribological performance was detected by measuring the voltage for a lubricant with various additive concentrations. The roller wear rate was found to be strongly dependent upon both the rising rate of voltage in the wear process and the time period needed to create a positive voltage. The antiwear effect of differing additive concentrations was evaluated using the measurements of voltage for various operating conditions. An increase in rotational speed, with a lubricating oil with a low additive concentration, decreases the wear rate. A lubricating oil with a high additive concentration does little to decrease the wear rate at low rotational speeds.
An experimental investigation into the wear of the cylinder liner‐piston ring in engines
Authors: Yingcai Zhang , Yun Lu , Houjun Zhang 
Published: July 2006

AbstractIn order to meet the demands of different engines, various kinds of material are used for the cylinder liners and piston rings. This paper describes a method and the results of wear tests for various liners and rings. These experiments were carried out on a FGM‐1 wear simulation testing machine. The results help contribute to the rational selection and pairing of the liners and the rings.
Condition monitoring of industrial machinery through lubricant oil analysis
Authors: de A. Leão V. M. , Jones M. H. , Roylance B. J. 
Published: July 2006

AbstractA number of techniques exist that can be used to determine the condition of a machine by analysing a sample of the lubricant. However, there are only a few available techniques that can be used to determine the effect of more than one cause of deterioration with a single method of analysis.By sensing changes in the dielectric of the lubricant, it is possible to obtain information relating to both the deterioration of the machine by means of wear products, and the influence of any solid and liquid contaminants present in the lubricant.In this paper, the principle of operation for this method is described, and the results of some controlled tests are reported in which comparisons are made with results obtained using other types of ‘health’ monitor.
Erosive wear of selected metals in coal washing environments
Authors: Yinghuai Qiang , Renli Fu , Dunlun Zhu 
Published: July 2006

AbstractA slurry erosive wear apparatus developed by the authors has been used to test the erosive wear behaviour of selected metals in coal washing environments.The erosive wear test machine was employed to determine the effects of (1) carbon content in carbon steels, (2) chromium content in alloy steels, and (3) corrosion of aqueous solutions on the erosive wear behaviour of metals. The test results revealed that the carbon content in annealed carbon steels slightly affects the erosive wear resistance of metals, while the increase in chromium content of alloy steels apparently improves the erosive wear resistance of metals and, when a corrosion inhibitor is added to slurries, the erosive wear rates of metals reduces significantly.Two types of micro‐mechanism were deduced from the observation of eroded surfaces by SEM: (1) local exfoliation, and (2) micro‐cutting. The corrosion inhibitor can alter the micro‐mechanism from local exfoliation to micro‐cutting. The analyses show that the erosive wear of selected metals in slurries results from the synergistic effects of wear by solid particles plus fluid corrosion.
Prediction of bearing corrosion and correlation with the petter W1 L engine test
Authors: Goujon G. , Abellaneda G. , Desvard A. , Hipeaux J. C. 
Published: July 2006

AbstractAmong the engine oil tests required by European and American specifications, is a test of copper‐lead piston rod bearing resistance to corrosion. This is carried out on a single‐cylinder Fetter W1 L or Labeco CLR engine.Using the same oils, a GFCFrench co‐ordinating group for the development of performance tests for fuels, engine oils, and other transportation lubricants.
working group responsible for developing laboratory test methods for screening lubricants, has devised a test for studying the corrosion behaviour of a lead sample. In the presence of copper, it is immersed in the test lubricant, which is subjected to severe oxidation conditions, in the presence of air, at high temperature. The results obtained from this test agreed perfectly with the engine test results. Furthermore, the laboratory test showed good repeatability and reproducibility.
Tribological behaviour of plasma sprayed Al2O3 and TiO2 ceramic hard coatings under dry contact
Authors: Krishna Kumar V. , Swarnamani S. 
Published: July 2006

AbstractPlasma sprayed ceramic coatings are used in a number of industries in which surface modification of components to compare tribological properties is important: so hence, are evaluations of their tribological properties. This paper presents a study on the wear behaviour of three ceramic coatings — Al2O3, TiO2 and Al2O3‐TiO2combination — in the load and speed ranges of 5 to 50 N, and 0.3 to 10 m/s, respectively, on which few data are available in the literature. The tests were carried out using a standard dry sand rubber wheel abrasion test and a pin‐on‐disc machine under dry sliding conditions. It was found that a stick‐slip effect seems to occur at low sliding speeds, and transition takes place at a sliding speed of around 4 m/s. Of the three ceramic coatings, TiO2 was found to be the most wear resistant, with the least friction coefficient, although it is less hard than the Al2O3 coatings. Scanning electron microscopy of the surface shows evidence of wear mechanisms such as plastic deformation, transfer‐film formation, micro cracks, and grain pull‐out in the coatings.
A screening test for anti‐wear additives in a modified four‐ball test
Authors: Cazin J. , Téqui P. , Lesieur Y. 
Published: July 2006

AbstractModern engine tests that evaluate the anti‐wear properties of automotive engine oils are increasingly sophisticated and expensive, and often have relatively poor precision. The development of a simple, inexpensive, and reliable bench test to screen the anti‐wear properties of fully formulated engine oils prior to their testing in engines is therefore very attractive. Numerous methods already exist, but they typically measure wear only at the end of the test by measuring the consequences of wear. The present paper describes an alternative approach, its purpose being the comparative evaluation of the anti‐wear performance of lubricants throughout the test under variable load. A four‐ball machine was used as a test rig for this work, and was equipped with instruments allowing study of the oil bath temperature, load applied to the balls, and the displacement of the load lever arm.The work presented focuses on a test procedure containing the following important elements: pre‐ageing of oils, test start‐up at very low load, incremental increases in load, stepwise increase in load, with each step sufficiently long to allow system equilibrium.Recording and analysis of the temperature and arm displacement curves permit the recognition of two distinct forms of wear: slow and gradual abrasive wear, and sudden and intense adhesive wear (scuffing). The presence and the intensity of the latter were found to have a direct relation with the anti‐wear performance of candidate oils in the API Sequence VE engine test. The procedure ranked oils correctly in relation to their dithiophosphate concentration, correctly distinguished secondary and primary zinc dithiophosphates and, more interestingly, predicted the positive effects of some ashless anti‐wear additives in accordance with results obtained in the Sequence VE.
Examination of tribological properties of plasma surface layer using special test equipment
Authors: Škoriˇ B. , Kakaš D. 
Published: July 2006

AbstractThe hardness, adhesion, and tribological behaviour of magnetron‐deposited coatings (TiN and (Ti,Al)N) have been determined and related to microstructure composition. To enhance the adhesion of the coating, plasma nitriding of substrates was employed. Wear behaviour, coefficient of friction and contact temperature were measured using computerised data acquisition and processing. The bonding force between the coated samples and counter material was monitored and controlled by newly designed and constructed equipment, to keep a constant level of load during sliding. With the new hardware and software, it was possible to monitor on‐line the development of the wear process. The hardware consisted of PC computer, piezoelectric transducer, sensors with high sensitivity, microprocessor‐controlled measuring system, AD/DA transformer, and multichannel plotter. The wear zone morphology and characteristics of the surface layer structure and other important properties were investigated using scanning electron microscopy (SEM) and X‐ray diffraction analysis (XRD). Energy dispersive X‐ray analysis (EDAX) of the wear scars on pins provided essential information on the wear characteristics. Based on the results, the correlations between the mechanical properties, the surface structure, and tribological characteristics are explained.
Method for continuous detection of different friction and wear regimes and application to the behaviour of ceramics at high temperature
Authors: Dalverny Olivier , Denape Jean 
Published: July 2006

AbstractThis paper describes tests carried out on a tribometer functioning at high temperature and equipped to record continuously the various test parameters, namely, the normal applied load, the tangential friction force, the differential movement of the contact surfaces, and the temperature of the sample. Dry friction tests, conducted on two aluminas of different purities, showed different degradation regimes at both 20 and 800°C. Thus, three successive periods of functioning were identified and correlated with transitions in the mechanism of degradation of the surfaces or in the mechanism of interfacial adaptation in the contact. The first period corresponds basically to the adaptation mechanisms of the interfaces with no wear material generated. The two subsequent periods demonstrate the degradation mechanisms of the surfaces leading to the production of more or less wear material and resulting in different states of equilibrium between production, recirculation, and loss of wear debris through the contact.
Determination of Calcium, Zinc, and Phosphorus in multigrade crankcase oils by XRF, DRES, and ICP‐AES
Authors: Patel M. B. , Christopher J. , Jain S. K. , Srivastava S. P. , Bhatnagar A. K. 
Published: July 2006

AbstractThe effect of viscosity index improvers such as styrene‐isoprene copolymer (SICP), styrene‐butadiene copolymer (SBCP), ethylene‐propylene copolymer (OCP) and poly(alkyl) methacrylate (PMA), in multigrade oils on the determination of Ca, Zn and P in fresh and used lubricating oils was studied using XRF, DRES and ICP‐AES techniques. Crankcase lubricating oil blends containing known amounts of Ca (2900 ppm), Zn (1700 ppm) and P (1600 ppm) were further formulated with different concentrations of these VI improvers and analysed for their Ca, Zn, and P contents by XRF, DRES and ICP‐AES. Based on a comparison of the resulting analytical data, it was concluded that the VI improvers had no effect on the analysis results, and that the concentrations of Ca, Zn and P in the oil determined by these techniques correlate well with each other.
Determination of the Bingham parameters of an electrorheological fluid in an axial flow concentric‐cylinder rheometer
Authors: Kohl James G. , Tichy John A. , Craig Kevin C. , Malcolm Skye M. 
Published: July 2006

AbstractElectrorheological (ER) fluids are fluids that undergo changes in their rheological properties in the presence of an applied electrical field. The change in the flow properties with an applied electrical field has led to their being investigated for use as ‘smart’ lubricants. The Bingham model is currently used to describe the behaviour of these fluids. In this work, the Bingham model parameters of a commercially available ER fluid are obtained using an axial flow concentric‐cylinder rheometer. Two methods are used to determine these parameters. One is the Weissenberg (—Rabinowitsch) method applied to thin annular slits, to obtain corrected stress—strain rate information. The other method involves directly fitting the velocity—pressure curve data to the axial flow rate equation of a Bingham fluid through concentric cylinders. The results obtained by these two methods differ by as much as 49.4 and 63.5% for the yield stress and viscosity, respectively.It is observed for this ER fluid that the yield stress increases according to a power law relationship with the applied electrical field. The viscosity appears to decrease linearly with an increase in the applied electrical field.
A laboratory technique for the evaluation of automotive gear oils of API GL‐4 level
Authors: Bisht R. P. S. , Singhal Sudhir 
Published: July 2006

AbstractAutomotive gear oils, as typically used in rear axles, are normally evaluated in terms of their performance in full‐scale bench tests. One such test is the CRC L‐19/CRC L‐42 test, which is included in API and other specifications. The L‐19 test method is now obsolete, and the L‐42 is used basically to define GL‐5 level oils. An indigenous test method, IIP Method VAV‐382, has been developed at the Indian Institute of Petroleum on an Amsler machine, operating under sliding conditions between two discs, and is also included in the IS:1118‐92 specification for multi‐purpose gear oils for GL‐4 level oils. This method has been re‐examined to obtain better resolution of scuffing of the disc surfaces. The modified procedure has proved effective, and the procedure and results for various commercial oils are described in this paper, which shows the method to be effective for the evaluation of GL‐4 level oils.
Pulsed field gradient (PFG) NMR spectroscopy: An effective tool for the analysis of mixtures of lubricating oil components
Authors: Kapur G. S. , Berger S. 
Published: July 2006

AbstractIn the presently reported work, the multinuclear two‐dimensional (2D) diffusionordered nuclear magnetic resonance (NMR) spectroscopy (DOSY) technique based on the pulsed field gradient (PFG) has been used in experiments to analyse mixtures of lubricating oil components. One‐dimensional (1D) PFG experiments have also been used to simplify and edit the NMR spectra of the mixtures. Such experiments provide a clean spectrum of the highest molecular weight (slower diffusing) component by eliminating the signals of lower molecular weight (faster diffusing) components, without any prior physical separation. These pulsed field gradient experiments not only facilitate the separation of resonance signals of different components, but also lead to their subsequent identification, and provide information about the number and structure of components in a mixture. Some examples of our initial efforts to establish 1D and 2D PFG‐based NMR experiments for the analysis of mixtures of lubricating oil components are given and assessed to illustrate the potential applications of such techniques in the field of lubricating oils.
Analysis of engine oil and phosphorus volatility
Authors: Selby T. W. 
Published: July 2006

AbstractAn apparatus has been designed that allows the measurement of phosphorus volatility, which is important in, among other things, controlling the degradation of exhaust catalysers in automobiles. Following on from the original Noack volatility test, the Selby—Noack apparatus can measure up to 99.9% of volatiles. The apparatus has been used in the present work to assess the relationship between engine oil volatility and engine oil phosphorus volatility (from additives), some reflections on which are presented.
Major pathways for used oil disposal and recycling. Part 1
Authors: Kajdas Czeslaw 
Published: July 2006

AbstractOne of the main concerns with lubricating oil relates to used oil management for both industrial and engine oils, although the environmental impact of gasoline and diesel engine oils is the most critical. Provided that efficient management systems are in place, most used oil should not reach the environment, so, the major question is how to dispose of collected used oil. The first option lies in burning it as a fuel, the second in recycling (reclaiming, reprocessing, re‐refining). The latter allows recovery of mineral base oils, which are valuable constituents of crude oil.Mobile (on site) and fixed plants for industrial oil recycling will first be discussed, and the paper will look at the most modern re‐refining processes that produce base oils of as high quality as virgin base oils. Based on current re‐refining experience, the quality of finished lubricants blended from re‐refined base stocks is also noted. Re‐refining today may be of significant benefit to the economy and can, of course, protect the environment. All modern re‐refining technologies produce small amounts of by‐products in which toxic materials may have been concentrated. A final aspect of reprocessing used oil is to integrate it, after hydrogen treatment, into existing refineries. This valuable raw material can then be directly routed to a lube oil unit or even to a cracking unit for conversion to gasoline. The integration of used oil treatment processes into selected refineries may be the most effective pathway to used oil disposal.In this first part, the author looks at the nature of the problems associated with used oil, its use as a fuel, and simple recycling. He then goes on to look at major re‐refining processes, starting with hydrogenation (KTI, Mohawk, BERC/NIPER, and PROP technologies). Part 2 will describe other processes, including a range of vacuum distillation/clay treatment technologies.
Influence of operating conditions on friction and temperature characteristics of a wet clutch engagement
Authors: Holgerson Mikael 
Published: July 2006

AbstractTo optimise the gear change in automatic transmissions, more knowledge is needed of the engagement behaviour of wet clutches. A factorial design investigation of the engagement of a wet clutch has been carried out. The friction and temperature characteristics have been studied. The experiments were carried out in an apparatus that can vary sliding velocity, drive torque, inertia, force rate, and lubricant flow. The results show how these parameters affect the response data: engagement time, developed energy, temperature rise, maximum torque, maximum power, static friction, dynamic friction, and initial friction. There are interaction effects between some of the input parameters, but they are relatively small. The friction coefficient varies over time but is independent of the input parameters, except for dynamic friction, which decreases with increasing sliding velocity, drive torque, and inertia. The temperature rise was found to be proportional to developed energy and both these were most affected by sliding velocity. The drive torque and force rate have the greatest effect on the engagement time.
Analysis of micropitting of prototype surface fatigue test gears
Authors: Hoeprich Michael R. 
Published: July 2006

AbstractThe early stages of micropitting were examined on experimental gears designed for surface fatigue studies by the Helical Gear Rating Committee of the American Gear Manufacturers Association. Optical profilometry, scanning electron microscopy, and metallographic examinations were conducted on the first prototype gearset tested. The gearset was tested in an FZG test rig. To evaluate tooth bending fatigue strength, the gears were loaded to load stage 12. A tooth broke from bending fatigue in 0.88 h (the expected time). This short runtime allowed for the examination of micropitting at an early stage of development. The distribution and morphology of micropitting over the tooth face and associated relationships with surface micro‐ and macrogeometry features and traction have been examined. Micropitting was primarily associated with finish geometry. A few pits were associated with sulphide inclusions and one pit was possibly initiated by a small non‐metallic inclusion. Metallographic examinations revealed asperity‐related lines of dark etching alterations caused by high asperity contact and traction stresses.
Stick‐slip in the presence of a normal vibration
Authors: Krallis M. , Hess D. P. 
Published: July 2006

AbstractThis paper presents a dynamic analysis of a contact system subjected to an applied normal vibration. The tangential motion of the system is found to exhibit stick‐slip behaviour dependent on the applied vibration, even in the absence of a difference in static and kinetic friction or a negative gradient in the friction‐velocity relation. The analysis leads to the development of a criterion for stick‐slip in the form of an equation defined in terms of the system and input parameters. This criterion is also presented graphically and is assessed through a series of experiments. The analysis and measurements show that stick‐slip occurs for a significantly wider drive velocity range when the normal vibration applied is near the natural frequency of the drive system. In addition, when stick‐slip occurs in the presence of a normal vibration, the frequency of stick‐slip is found to lock in to the frequency of the applied vibration.