bluuebunny/crossref_metadata_2025_split huggingface dataset:
Use of lubricants during cold rolling of aluminium
Authors: Zhang S. , Lenard J. G. 
Published: July 2006

AbstractNatural and synthetic lubricants specially formulated for cold rolling of aluminium were evaluated in terms of their ability to lower mill loads. The use of additives was also studied. Roll separating forces and roll torques were monitored. No significant differences between natural and synthetic oils were observed. The ability to maintain lubricant action was found to be lowest when synthetic esters were present, either in the base oil or as an additive.
Polymer esters and their synergy with ZDDP – the possibility of reducing ZDDP content in lubricants
Authors: Wallfahrer U. 
Published: July 2006

AbstractIn recent years, environmental awareness and legislation have enforced ever greater controls on the emissions of motor vehicles. To meet those requirements, the increased use of exhaust port catalysts is almost inevitable. However, there are concerns that lubricant‐derived phosphorus compounds could in the long term be detrimental to those catalysts and make it necessary to reduce the W D P level in the lubricating oils.Laboratory bench tests and engine rig tests show that a significant reduction of the level of ZDDP may be possible in the presence of a special class of polymer esters without reducing the wear performance of the engine oils.
Performance of fluid and solid lubricants in spacecraft applications
Authors: Fleischauer Paul D. 
Published: July 2006

AbstractResults of a series of lubricant screening and performance tests are described that provide criteria for the selection of proper Lubrication for precision spacecraft mechanisms, such as reaction wheels, gyroscopes, solar array drives, and gimbals. An eccentric, thrust—bearing apparatus was used for rapid screening and relative ranking of lubricants, and results are compared to life test data for a series of oils. Synthetic hydrocarbon oils and greases are recommended for the first three types of mechanism, while newly developed, high density, oriented, MoS2, films are recommended for gimbals.
High‐temperature tribology of future diesel engines
Authors: Kamo Roy , Bryzik Walter 
Published: July 2006

AbstractFuture diesel engines will be operated at higher cycle temperatures. These higher cycle temperatures will invariably pose tribological problems of the top ring, piston, valve seats, and valve guides. Current lubricating oil with a thermal oxidative stability up to 204°C will be inadequate: polyol ester‐base formulated synthetic oil, such as Stauffer Chemical SDL‐1 or US TACOM MRI‐1, with 310°C thermal oxidative stability could possibly be the next generation of lubricating oil.However, as we get nearer to the time when diesel engines will be constructed in advanced structural ceramics or composites for ‘adiabatic’operation, the thermal stability of the lubricating oil will have to approach 445°C.To withstand a top ring reversal temperature beyond 310°C, polyphenyl ether base oil and other high‐temperature liquid lubricants are sought, but the highly aromatic polyphenyl ether type oil has thus far shown little promise for this application. The hybrid piston with solid lubricated top ring has potential. Densified Cr2O3 on Cr2O3 has demonstrated the possibility of operating at 380°C top ring reversal temperature, with acceptable wear and life. NASA PS212 with Stellite 6B has also been tested without a liquid lubricant.The tribological needs of the next generation of high‐output, high‐temperature diesel engines can therefore be met with the synthetic polyol ester base, cost‐effective, formulated lubricant. The adiabatic ceramic engine will require much higher temperature capability. To this end, tribologists will have to direct their efforts to other higher temperature liquid lubricants and to solid lubricants. A laboratory coefficient of friction of < 0.06 must be achieved in order to maintain acceptable brake‐specific fuel consumption. This target is based on cast iron on cast iron with lubricating oil, and it must be achieved with acceptable wear and cost.
Biodegradability of lubricant base stocks and fully formulated products
Authors: Völtz Martin , Yates Neil C. , Gegner Eberhard 
Published: July 2006

AbstractIncreasing awareness of the environmental impact of consumer and industrial products has produced a demand for lubricants that biodegrade. There is a number of biodegradation tests that can be used on lubricants, although not all are always appropriate, as this paper explains. The CEC test is among the best known and is in use for both conventional and synthetic oils. There will, in future, be a greater movement to biodegradable oils in Europe, perhaps extending to all oils.
Assessment of the biodegradability of mineral oil and synthetic ester base stocks, using CO2 ultimate biodegradability tests and CEC‐L‐33‐T‐82
Authors: Novick N. J. , Mehta P. G. , McGoldrick P. B. 
Published: July 2006

AbstractThe EPA (Gledhill) Shake Flask test, OECD Modified Sturm test, and CEC (CEC‐L‐33‐T‐82) Biodegradability test have been used to assess the degradability of mineral oil, natural ester, and synthetic ester base stocks. The Shake and Sturm tests are ultimate biodegradability tests which determine the percentage of test material carbon converted to CO2 over a 28‐day period; the CEC test determines, at 21 days, the disappearance of the carbon‐hydrogen stretch in Freon extracts of the test medium. In all three tests, the test material is added to a mineral salts medium, the medium is inoculated with mixed liquor from a municipal waste water treatment plant and test flasks are shaken. The Shake Flask and CEC tests were able to show expected differences in degradability between paraffinic and naphthenic mineral oils. A poor correlation was found between ultimate biodegradability test results and results from the CEC test when synthetic esters were studied. Dissolved organic carbon (DOC) analysis of the test medium indicated that degradation of some synthetic esters led to the accumulation of water‐soluble metabolites which are not extractable into Freon, as required for quantification by the CEC test. Thus, while the CO2 tests detected differences in the degradability of these test materials, the CEC test did not. The CEC test can, therefore, overestimate degradability of some synthetic esters, leading to the erroneous conclusion that these materials would meet OECD Ready Biodegradability criteria. Biodegradability results for the EPA, OECD, and CEC tests are presented and results compared.
Tribological properties of some water‐based lubricants containing polyethylene glycol under boundary lubrication conditions
Authors: Yong Wan , Qunji Xue , Lili Cao 
Published: July 2006

AbstractThe metal‐working industry is increasingly interested in synthetic metalworking fluids and coolants. The excellent lubricating properties of polyalkylene glycols have been recognised in areas such as gear lubricants, hydraulic fluids, and compressor lubricants. The main purpose of the present work was to investigate the friction and wear properties of several polyethylene glycols and their synergy with a common water‐soluble EP additive, using four‐ball and ball‐on‐plate tribometers.
Polysiloxane substituent influence on the foaming of polyolesters and polyolester turbine engine lubricants
Authors: Centers Phillip W. 
Published: July 2006

AbstractParts‐per‐million (ppm) quantities of polysiloxanes with different molecular structures have varying effects on the foaminess of a polyolester, trimethylolpropaneheptanoate (TMPH), and a formulated synthetic polyolester gas turbine engine lubricant. At the 100 ppm concentration evaluated in a standard foam test, TMPH‐polysiloxane mixtures that exhibit lower interfacial surface tension produced copious quantities of foam. Estimates of Lewis acid‐base interaction and solubility of the additive in the polyolester are not helpful in predicting foaminess. Consideration of additive polymeric structure, the potential for increased additive molecular entanglement due to substituent length, and interaction of adjacent polysiloxane molecules at the surface, are helpful in rationalising differences observed in foaming. Some lubricant additives, such as antioxidants and antiwear agents, appear to enhance the profoamant tendencies of selected polysiloxanes.
Advanced lubricants for heat engines
Authors: Hsu S. M. , Perez J. M. , Ku C. S. 
Published: July 2006

AbstractAn advanced liquid lubricant for heat engines has been developed and tested successfully in a prototype engine. The lubricant possesses superior oxidation stability and high temperature stability. With the advent of new engine designs, stability should be measured in terms of both the temperature and the time for which the lubricant is subjected to it. This lubricant is designed to provide friction and wear protection for three to five minutes at 425°C (800°F) at the ring zone and maintains stability at an oil sump temperature of 171°C. The lubricant has been evaluated by the Cummins Engine Company. Out of a field of several dozen lubricants, six lubricants were selected for a prototype 200 h endurance tests. The NIST lubricant was one of the two lubricants that successfully finished the endurance testing. This paper provides an overview of the key lubricant design considerations, including oxidation and thermal stability, volatility, and deposit control, the prototype engine test conditions and the results.
Diversification of automatic transmission fluid technology
Authors: Fewkes Roy , Hughes David G. , Joseph Ivan E. , Sumieski James L. 
Published: July 2006

AbstractA range of commercially available automatic transmission fluids (ATFs) was tested, in order to compare their performance both with each other and with broadly accepted European market requirements. The test results showed a considerable variance in the performance of the fluids, despite their conformity to a common ATF specification. Furthermore, when the latest transmission developments are considered, it becomes clear there is, in many instances, a divergence of performance requirements. One area of potential conflict is the different emphasis on passenger cars as against commercial vehicles in the North American and European markets. The paper examines factors that influence ATF performance requirements, and the areas of compromise if a common fluid is needed. Suggestions are made to address those circumstances where it seems that performance needs are too divergent.
The application of matrix‐assisted laser desorption/lonisation time‐of‐flight mass spectrometry (MALDI‐TOF MS) to the analysis of lubricants. part 1. polyol ester aviation turbine engine oils
Authors: Bartl P. , Völkl Ch. 
Published: July 2006

AbstractIn the present work, Matrix‐Assisted Laser Desorption/lonisation Time‐of‐Flight Mass Spectrometry (MALDI‐TOFMS) is demonstrated to be a valuable method for the analysis of synthetic polyol ester turbine engine oils. A softionisation technique, it generates, under adequate experimental conditions only, (quasi‐)molecular ions and allows detection and identification of all components including di‐ and tripentaerythritol esters and oligomeric additives, without pre‐separation.
Lubrication by bionic synovial fluids in the human urinary system
Authors: Dehua Tao , Wanqi Yan , Guoqing Xie 
Published: July 2006

AbstractThe patient suffers a lot when cystoscopes or catheters are inserted into the urinary system. In order to lower friction whilst being non‐poisonous, nonfungoid, and meeting other medical requirements, a new bionic medical lubricant has been synthesised. In tests imitating the friction condition between skin and plastic apparatus, eel fish synovia, white oil, glycerol, polyethylene glycol in aqueous solution, Tween‐80, a proprietary medical lubricant, and the candidate fluid were tested. The results of these tests demonstrated that the synthesised lubricant performs best, with eel fish synovia second, and glycerol last.The test fluid has been trialled in some key hospitals (Shanghai, Beijing, Guangzhou, and Shijia Zhuang), and the results showed that about 95% of patients experienced no pain, and about 5% had a slight feeling, with no reported discomfort. The candidate bionic medical lubricant is in use by doctors in medical practice.
A tribological study of an S,P‐containing benzotriazole derivative as an additive in pentaerythritol ester
Authors: Tianhui Ren , Jian Xia , Longzhen Zheng 
Published: July 2006

AbstractThe load‐carrying capacity, antiwear and friction reduction properties of an S,P‐containing benzotriazole derivative (BMDDP) added to a synthetic lubricant (pentaerythritol ester) were evaluated using a four‐ball test machine. The results when compared with those of tricresyl phosphate (TCP) and zinc dialkyldithiophosphate (ZDDP) show that, in pentaerythritol ester, the novel compound (BMDDP) is an excellent multifunctional additive, which possesses better load‐carrying capacity, antiwear and friction reduction properties than either TCP or ZDDP. The rubbed surfaces were analysed using XPS and EPMA, and the antiwear mechanism is discussed.
On the effects of friction on free volume holes in PTFE
Authors: Qunji Xue , Feng‐Yuan Yan 
Published: July 2006

AbstractSince the macroscopic properties of materials are relevant to their micro structure, the detection of microscopic defects or their changes in size and concentration is an interesting topic in materials science. The positron annihilation lifetime (PAL) method used here is established as a unique technique that can provide information about the size and concentration of free volume holes directly without significantly intervening in the bulk properties of the specimens. To our knowledge, this is the first time that PAL techniques have been used to study the wear mechanism of macromolecular tribomaterials. Here we present the results of a study in which the correlation between the fretting wear behaviour of polytetrafluorethylene (PTFE) and the changes in its free volume size and concentration in amorphous‐crystal interface regions was found to be δω =A.δτ3, where δω is the wear loss of PTFE under fretting wear conditions, A is a constant, and δτ3 represents the relative change in the third lifetime components after the friction test. The results indicate that fretting mainly influences the characteristics of atomic‐scale free volume holes in the amorphous‐crystal region in PTFE, and under high‐load fretting wear conditions the ductile polymer PTFE possesses a self‐curing function for its defect‐free micro volume holes.
Lubrication performance of model organic compounds in high oleic sunflower oil
Authors: Minami Ichiro , Hong Hyun‐Soo , Mathur Naresh C. 
Published: July 2006

AbstractGenetically modified sunflower oil, so called ‘high oleic’ sunflower oil, is a promising and environmentally friendly fluid that possesses many advantages as a lubricating oil. It will be more usable if its performance as lubricating oil can be optimised by additives. In the present study, we have examined model friction modifiers under boundary lubrication conditions to understand their applicability to vegetable oils. Octadecanoic acid provides good lubricity. Octadecyl amine and octadecanamide are also acceptable, whereas octadecane thiol exhibits a negative effect on lubricity.
The application of Matrix‐Assisted Laser Desorption/Ionisation Time‐of‐Flight Mass Spectrometry (MALDI‐TOF MS) to the analysis of lubricants. Part 2. used polyol ester aviation turbine engine oils
Authors: Bartl P. , Völkl Chr. , Kaiser M. 
Published: July 2006

AbstractIn the present work, Matrix‐Assisted Laser Desorption/Ionisation Time‐of‐ Flight Mass Spectrometry (MALDI‐TOF MS) is demonstrated to be a valuable technique in the characterisation of used polyol ester oils, and one which includes details of the base‐oil and additive degradation chemistry. The results are confirmed by GC/MS and 13C‐NMR data.
Oxidative stabilisation of synthetic fluids and vegetable oils
Authors: Hamblin Peter 
Published: July 2006

AbstractThe use of ashless antioxidants to increase the useful working life of synthetic fluids, such as polyalphaolefins, polyalkylene glycols and carboxylic acids, is discussed, and some general guidelines are proposed. The application of ashless antioxidants in controlling the oxidative degradation of several different types of biodegradable vegetable oil is illustrated. The action of the naturally occurring antioxidant, vitamin E, in some of these fluids has been examined and some preliminary results are reported.
Wear performance of tribologically modified thermoplastic composites at elevated temperatures
Authors: Reinicke R. , Hoffmann J. , Friedrich K. 
Published: July 2006

AbstractThe use of injection moulded thermoplastic composites is increasing, but without fillers, reinforcements, or lubricants, they are limited by their thermal behaviour. This study looks at four polymers — polyamide 46, polyphthalamide, polyetherimide, and polyphenylenesulphide — containing first glass fibres as reinforcement, and a second version with added PTFE. Two types of wear test were undertaken, sliding wear (pin‐on‐disc and block‐on‐ring), and reciprocally fretting wear. The test materials showed different wear rates both under different tests and at various temperatures.
Hydrolytic stability of synthetic ester lubricants
Authors: Boyde S. 
Published: July 2006

AbstractThis paper looks in detail at hydrolysis of esters. While this is not normally a problem, hydrolytic stability can be an important consideration, e.g., in air compressors. The paper looks first at the synthesis of esters, which is a reversible reaction of acid + alcohol ↔ ester + water, usually involving a catalyst. Two mechanisms of ester hydrolysis, namely base‐catalysed and acid‐catalysed, are described as being most relevant to lubricant esters, the former being less likely than the latter. Two extended tests are described which have been used in the author's laboratory, a beverage‐bottle test (modified ASTM D‐2619), and a sealed‐tube test, for hydrolytic measurement. The paper goes on to look in detail at the effect of ester structure on rate of hydrolysis, in terms of resonance effects and steric effects, on the effect of impurities, and of acidic and acid catcher additives.
A friction coefficient of 0.05 in aqueous systems
Authors: Zwinselman Jan 
Published: July 2006

AbstractLow friction coefficients, i.e., below 0.10, in mineral oil based lubricants have been traditionally obtained using glycerol mono oleate, molybdenum dithiocarbamate or molybdenum dithiophosphate. In aqueous systems this is more difficult to achieve, and wear protection is also problematic due to the polar nature of the substrate. There is substantial interest in low toxicity/ecotoxicity additives, especially in metalworking fluid applications, where disposal of the finished fluid can be expensive. In this paper, a novel ashless (metal‐free) friction modifier with antiwear properties, specifically designed for aqueous systems, is reviewed. This additive does not contain phosphorus, sulphur, or halogens. Some preliminary results in water based lubricants, for example, polyalkylene glycols, for metal forming applications are presented.
Environmentally adapted lubricants, Part II. Hydraulic fluids
Authors: Pal Mahendra , Singhal Sudhir 
Published: July 2006

AbstractCurrent technologies relating to hydraulic fluids are mostly either mineral based, synthetic based, or water‐based. Mineral oil based hydraulic fluids tend to be used for their excellent lubrication characteristics, economic viability, and so account for almost 90% of hydraulic fluids, while waterbased fluids tend to be employed in fire hazard applications. Synthetic hydraulic fluids possess superior properties to mineral oils, but their higher price limits their application to aerospace and special applications under severe conditions. In recent years, biodegradable hydraulic fluids, which are readily decomposed by micro‐organisms, have come into focus due to the rise in environmental consciousness in European countries, particularly Sweden and Germany, and with this, vegetable‐based fluids.In the present paper, the main categories of hydraulic fluids, including environmentally friendly fluids, are discussed in an overview of the state of technology in this area. Current governmental regulation, and the properties required of environmentally adapted fluids, and an appraisal of the current practices in various countries are also given.In an earlier paper*, the authors reviewed the key aspects of and requirements for environmentally adapted lubricants, namely, chemical composition, eco‐toxicity, biodegradability, bio‐accumulation, eco‐labelling schemes, and life‐cycle analysis.In the present paper, the main categories of hydraulic fluids, including environmentally friendly fluids, have been described. In Part I*, the authors reviewed the key aspects of and requirements for environmentally adapted lubricants.
Dynamic friction measurements with an atomic force microscope on polymer surfaces
Authors: Krotil Hans‐Ulrich , Marti Othmar 
Published: July 2006

AbstractThe combination of scanning friction force microscopy (SFFM) and lock‐in techniques leads to dynamic SFFM (DSFFM) and provides great advantages in friction force studies with sub‐micrometre resolution. In this paper are presented measurements on thin adsorbed organic films on polymers (polymer blend of 75% poly(allylaminehydrochloride) (PAA) and 25% poly(diallyl‐dimethylammonium chloride) (PDDAC)) and on mica (as a reference). The amplitude and phase response as a function of the excitation amplitude can be explained on hard surfaces by a simple static and dynamic friction model. This model allows us further to distinguish static friction forces and kinetic friction forces in a quantitative way. Furthermore, we demonstrate the use of these spectra to determine the correct modulation amplitude of the excitation to achieve the optimal friction contrasts directly. Polymer data suggest that the viscoelastic shear flow under the atomic force microscope (AFM) tip is responsible for the shape of the phase and amplitude spectrum. Lastly, we demonstrate that DSFFM is a useful technique for surface characterisation in situations where SFFM may not be adequate.
Nanoscale boundary lubrication of diamond‐like carbon coatings with fluorinated compounds
Authors: Kajdas C. 
Published: July 2006

AbstractProgress in the technology of magnetic media has brought about a remarkable increase in recording density. The most important factor determining the utility of magnetic disks is durability against head wear, and this durability is controlled by several factors. The present paper discusses the tribology of these media, particularly from the viewpoint of boundary lubrication. In that context there are two characteristic features of this lubrication regime: specific standard lubricants (fluoropolyethers such as Z‐DOL and perfluo‐ropolyethers such as Z‐15) and the newer application of these lubricants in the form of films only a few nanometers thick Advanced phosphazene‐type fluorinated compounds are of most interest at present, so these compounds are discussed in more detail. The emphasis is on X‐1P lubricant used either alone or as an additive for fluoro‐ and perfluoropolyethers deposited on protective diamond‐like carbon coatings.