temperature solid lubricant: Topics by WorldWideScience.org

Sample records for temperature solid lubricant

Atomistic study of ternary oxides as high-temperature solid lubricants

Science.gov (United States)

Gao, Hongyu

Friction and wear are important tribological phenomena tightly associated with the performance of tribological components/systems such as bearings and cutting machines. In the process of contact and sliding, friction and wear lead to energy loss, and high friction and wear typically result in shortened service lifetime. To reduce friction and wear, solid lubricants are generally used under conditions where traditional liquid lubricants cannot be applied. However, it is challenging to maintain the functionality of those materials when the working environment becomes severe. For instance, at elevated temperatures (i.e., above 400 °C), most traditional solid lubricants, such as MoS2 and graphite, will easily oxidize or lose lubricity due to irreversible chemical changes. For such conditions, it is necessary to identify materials that can remain thermally stable as well as lubricious over a wide range of temperatures. Among the currently available high-temperature solid lubricants, Ag-based ternary metal oxides have recently drawn attention due to their low friction and ability to resist oxidation. A recent experimental study showed that the Ag-Ta-O ternary exhibited an extremely low coefficient of friction (0.06) at 750 °C. To fully uncover the lubricious nature of this material as a high-temperature solid lubricant, a series of tribological investigations were carried out based on one promising candidate - silver tantalate (AgTaO3). The study was then extended to alternative materials, Cu-Ta-O ternaries, to accommodate a variety of application requirements. We aimed to understand, at an atomic level, the effects of physical and chemical properties on the thermal, mechanical and tribological behavior of these materials at high temperatures. Furthermore, we investigated potassium chloride films on a clean iron surface as a representative boundary lubricating system in a nonextreme environment. This investigation complemented the study of Ag/Cu-Ta-O and enhanced the
Surface Modification Of The High Temperature Porous Sliding Bearings With Solid Lubricant Nanoparticles

Directory of Open Access Journals (Sweden)

Wiśniewska-Weinert H.

2015-09-01

Full Text Available A surface modification of stainless steel bearing sleeves is developed to improve the tribology characteristics at high temperature. Solid lubricant nano- and microparticles are applied for this purpose. To create the quasi-hydrodynamic lubrication regimes, the solid lubricant powder layer is made by developed pressure impregnation technique. Porous sliding bearing sleeve prototypes were made by powder metallurgy technique. The purpose of the paper is to define the friction and wear characteristics of the sleeves and to determine the influence of sealing of the sliding interface on these characteristics. It is found that application of WS2 sold lubricant nano- and micro-particles and preservation of a particle leakage out of interface allows to achieve at the high temperature the friction coefficients comparable to those at ambient temperature.
Solid lubricants and surfaces

CERN Document Server

Braithwaite, E R

1964-01-01

Solid Lubricants and Surfaces deals with the theory and use of solid lubricants, particularly in colloidal form. Portions of this book are devoted to graphite and molybdenum disulfides, which are widely used solid lubricants in colloidal form. An extensive literature on the laboratory examination of hundreds of solids as potential lubricants is also provided in this text. Other topics discussed include the metals and solid lubricants; techniques for examining surfaces; other solid lubricants; metal shaping; and industrial uses of solid-lubricant dispersions. This publication is beneficial to e
Development of High Temperature Solid Lubricant Coatings

National Research Council Canada - National Science Library

Bhattacharya, Rabi

1999-01-01

... environment. To test this approach, UES and Cleveland State University have conducted experiments to form cesium oxythiotungstate, a high temperature lubricant, on Inconel 718 surface from composite coatings...
Solid lubricants in the power station

International Nuclear Information System (INIS)

Gaensheimer, J.

1981-01-01

Example application are first outlined, followed by descriptions of inorganic solid lubricants and plastics. Waxes, soaps and salts are discussed. Notes for usage are given. Solid lubricants in oils and greases are comprehensively described, followed by the sections entitled Solid lubricants for gearboxes . References to samples, tests, standards and bibliography make up the conclusion. (orig.) [de
Solid Lubricants and Coatings for Extreme Environments: State-of-the-Art Survey

Science.gov (United States)

Miyoshi, Kazuhisa

2007-01-01

An investigation was conducted to survey anticipated requirements for solid lubricants in lunar and Martian environments, as well as the effects of these environments on lubricants and their performance and durability. The success of habitats and vehicles on the Moon and Mars, and ultimately, of the human exploration of and permanent human presence on the Moon and Mars, are critically dependent on the correct and reliable operation of many moving mechanical assemblies and tribological components. The coefficient of friction and lifetime of any lubricant generally vary with the environment, and lubricants have very different characteristics under different conditions. It is essential, therefore, to select the right lubrication technique and lubricant for each mechanical and tribological application. Several environmental factors are hazardous to performance integrity on the Moon and Mars. Potential threats common to both the Moon and Mars are low ambient temperatures, wide daily temperature swings (thermal cycling), solar flux, cosmic radiation, and large quantities of dust. The surface of Mars has the additional challenges of dust storms, winds, and a carbon dioxide atmosphere. Solid lubricants and coatings are needed for lunar and Martian applications, where liquid lubricants are ineffective and undesirable, and these lubricants must perform well in the extreme environments of the Moon, Mars, and space, as well as on Earth, where they will be assembled and tested. No solid lubricants and coatings and their systems currently exist or have been validated that meet these requirements, so new solid lubricants must be designed and validated for these applications.
A Systems Approach to the Solid Lubrication of Foil Air Bearings for Oil-Free Turbomachinery

Science.gov (United States)

DellaCorte, Christopher; Zaldana, Antonio R.; Radil, Kevin C.

2002-01-01

Foil air bearings are self-acting hydrodynamic bearings which rely upon solid lubricants to reduce friction and minimize wear during sliding which occurs at start-up and shut-down when surface speeds are too low to allow the formation of a hydrodynamic air film. This solid lubrication is typically accomplished by coating the non-moving foil surface with a thin, soft polymeric film. The following paper introduces a systems approach in which the solid lubrication is provided by a combination of self lubricating shaft coatings coupled with various wear resistant and lubricating foil coatings. The use of multiple materials, each providing different functions is modeled after oil-lubricated hydrodynamic sleeve bearing technology which utilizes various coatings and surface treatments in conjunction with oil lubricants to achieve optimum performance. In this study, room temperature load capacity tests are performed on journal foil air bearings operating at 14,000 rpm. Different shaft and foil coating technologies such as plasma sprayed composites, ceramic, polymer and inorganic lubricant coatings are evaluated as foil bearing lubricants. The results indicate that bearing performance is improved through the individual use of the lubricants and treatments tested. Further, combining several solid lubricants together yielded synergistically better results than any material alone.
Thermochemical Stability and Friction Properties of Soft Organosilica Networks for Solid Lubrication

Directory of Open Access Journals (Sweden)

Pablo Gonzalez Rodriguez

2018-01-01

Full Text Available In view of their possible application as high temperature solid lubricants, the tribological and thermochemical properties of several organosilica networks were investigated over a range of temperatures between 25 and 580 °C. Organosilica networks, obtained from monomers with terminal and bridging organic groups, were synthesized by a sol-gel process. The influence of carbon content, crosslink density, rotational freedom of incorporated hydrocarbon groups, and network connectivity on the high temperature friction properties of the polymer was studied for condensed materials from silicon alkoxide precursors with terminating organic groups, i.e., methyltrimethoxysilane, propyltrimethoxysilane, diisopropyldimethoxysilane, cyclohexyltrimethoxysilane, phenyltrimethoxysilane and 4-biphenylyltriethoxysilane networks, as well as precursors with organic bridging groups between Si centers, i.e., 1,4-bis(triethoxysilylbenzene and 4,4′-bis(triethoxysilyl-1,1′-biphenyl. Pin-on-disc measurements were performed using all selected solid lubricants. It was found that materials obtained from phenyltrimethoxysilane and cyclohexyltrimethoxysilane precursors showed softening above 120 °C and performed best in terms of friction reduction, reaching friction coefficients as low as 0.01. This value is lower than that of graphite films (0.050 ± 0.005, a common bench mark for solid lubricants.
Tuning the Structure and Ionic Interactions in a Thermochemically Stable Hybrid Layered Titanate-Based Nanocomposite for High Temperature Solid Lubrication

NARCIS (Netherlands)

Gonzalez Rodriguez, P.; Lubbers, Roy; Veldhuis, Sjoerd; Narygina, Olga; Lette, Walter; Schipper, Dirk J.; ten Elshof, Johan E.

2017-01-01

Solid inorganic lubricants are thermally stable but they are often limited by their lack of deformability, while organic lubricants have limitations in terms of thermal stability. In this study, a novel solid organic–inorganic nanocomposite lubricant that synergistically combines the
Development of seismic support snubber using solid lubricant

International Nuclear Information System (INIS)

Sunakoda, Katsuaki; Akimoto, Kohichi; Uchi, Toshiyasu

1990-01-01

Solid lubricant MoS 2 films deposited by radio-frequency sputtering and a new physical process were applied to bearings and ball screws used in seismic support mechanical snubbers. The lubricity of MoS 2 films was maintained throughout 720 hours of exposure at a temperature of 200 degC. The endurance life of MoS 2 films using both radio-frequency sputtering and a new physical process was investigated by subjecting the mechanical snubber to a drag force test. Cumulative drag length reached 100 meters and 400 meters, respectively, for the two methods. The dynamic characteristics and durability of mechanical snubbers in an abnormal environment were also investigated. (author)
Hybrid n-Alkylamine Intercalated Layered Titanates for Solid Lubrication

NARCIS (Netherlands)

Gonzalez Rodriguez, P.; Yuan, H.; van den Nieuwenhuijzen, Karin Jacqueline Huberta; Lette, W.; Schipper, Dirk J.; ten Elshof, Johan E.

2016-01-01

The intercalation of different primary n-alkylamines in the structure of a layered titanate of the lepidocrocite type (H1.07Ti1.73O4) for application in high-temperature solid lubrication is reported. The intercalation process of the amines was explored by means of in situ small-angle X-ray
Is the boundary layer of an ionic liquid equally lubricating at higher temperature?

Science.gov (United States)

Hjalmarsson, Nicklas; Atkin, Rob; Rutland, Mark W

2016-04-07

Atomic force microscopy has been used to study the effect of temperature on normal forces and friction for the room temperature ionic liquid (IL) ethylammonium nitrate (EAN), confined between mica and a silica colloid probe at 25 °C, 50 °C, and 80 °C. Force curves revealed a strong fluid dynamic influence at room temperature, which was greatly reduced at elevated temperatures due to the reduced liquid viscosity. A fluid dynamic analysis reveals that bulk viscosity is manifested at large separation but that EAN displays a nonzero slip, indicating a region of different viscosity near the surface. At high temperatures, the reduction in fluid dynamic force reveals step-like force curves, similar to those found at room temperature using much lower scan rates. The ionic liquid boundary layer remains adsorbed to the solid surface even at high temperature, which provides a mechanism for lubrication when fluid dynamic lubrication is strongly reduced. The friction data reveals a decrease in absolute friction force with increasing temperature, which is associated with increased thermal motion and reduced viscosity of the near surface layers but, consistent with the normal force data, boundary layer lubrication was unaffected. The implications for ILs as lubricants are discussed in terms of the behaviour of this well characterised system.
Solid lubricant mass contact transfer technology usage for vacuum ball bearings longevity increasing

Science.gov (United States)

Arzymatov, B.; Deulin, E.

2016-07-01

A contact mass transfer technological method of solid lubricant deposition on components of vacuum ball bearings is presented. Physics-mathematical model of process contact mass transfer is being considered. The experimental results of ball bearings covered with solid lubricant longevity in vacuum are presented. It is shown that solid lubricant of contact mass transfer method deposition is prospective for ball bearing longevity increasing.
Thermal stability of solid lubricant element MoS2 in injection molded parts of 17-4 PH stainless steel

International Nuclear Information System (INIS)

Furlan, K.P.; Binder, C.; Klein, A.N.

2009-01-01

Sintered copper-based parts with self-lubricating properties are, nowadays, extensively employed, e.g. in automotive bushes. However, in such components, the liquid lubricant is added after the sintering stage. Recent developments have attempted to substitute the liquid lubricant for a solid one (which is incorporated during the mixing step), aiming operations under extreme conditions where liquids may be ineffective. For powder injection molding (PIM) market, stainless steels are the widest-ranging application group. In this study composites of 17-4 PH stainless steel with 10% vol. of molybdenum disulfide solid lubricant were prepared by PIM. The sintering of the compacts was carried out at various temperatures ranging from 650 to 1300 deg C. The composite structure was analyzed by SEM/EDS, and the phases formed were identified by XRD. Results indicated decomposition of MoS 2 during the sintering cycle, for temperatures above 650 deg C, with formation of others sulfides and supplementary diffusion of molybdenum into the matrix. (author)
The Tribological Performance of CrMoN/MoS2 Solid Lubrication Coating on a Piston Ring

Directory of Open Access Journals (Sweden)

Yuelan Di

2017-05-01

Full Text Available In order to improve the tribological properties of an engine piston ring and enhance its service life, magnetron sputtering technology and low temperature ion sulphurizing treatment technology were used to prepare CrMoN/MoS2 solid lubricant coating on the surface of an engine piston ring. The morphologies and compositions of the surface and cross-section of the sulfuration layer were analyzed by field emission scanning electron microscopy (FESEM, and wear property under high load, high speed and high temperature conditions were tested by a SRV®4 friction and wear testing machine. The results show that the CrMoN/MoS2 composite coatings appear as a dense grain structure, and the coating is an ideal solid lubrication layer that possesses an excellent high temperature wear resistance, reducing the engine operating temperature abrasion effectively and prolonging the service life of the engine.
Non-equilibrium responses of PFPE lubricants with various atomistic/molecular architecture at elevated temperature

Science.gov (United States)

Chung, Pil Seung; Song, Wonyup; Biegler, Lorenz T.; Jhon, Myung S.

2017-05-01

During the operation of hard disk drive (HDD), the perfluoropolyether (PFPE) lubricant experiences elastic or viscous shear/elongation deformations, which affect the performance and reliability of the HDD. Therefore, the viscoelastic responses of PFPE could provide a finger print analysis in designing optimal molecular architecture of lubricants to control the tribological phenomena. In this paper, we examine the rheological responses of PFPEs including storage (elastic) and loss (viscous) moduli (G' and G″) by monitoring the time-dependent-stress-strain relationship via non-equilibrium molecular dynamics simulations. We analyzed the rheological responses by using Cox-Merz rule, and investigated the molecular structural and thermal effects on the solid-like and liquid-like behaviors of PFPEs. The temperature dependence of the endgroup agglomeration phenomena was examined, where the functional endgroups are decoupled as the temperature increases. By analyzing the relaxation processes, the molecular rheological studies will provide the optimal lubricant selection criteria to enhance the HDD performance and reliability for the heat-assisted magnetic recording applications.
Non-equilibrium responses of PFPE lubricants with various atomistic/molecular architecture at elevated temperature

Directory of Open Access Journals (Sweden)

Pil Seung Chung

2017-05-01

Full Text Available During the operation of hard disk drive (HDD, the perfluoropolyether (PFPE lubricant experiences elastic or viscous shear/elongation deformations, which affect the performance and reliability of the HDD. Therefore, the viscoelastic responses of PFPE could provide a finger print analysis in designing optimal molecular architecture of lubricants to control the tribological phenomena. In this paper, we examine the rheological responses of PFPEs including storage (elastic and loss (viscous moduli (G′ and G″ by monitoring the time-dependent-stress-strain relationship via non-equilibrium molecular dynamics simulations. We analyzed the rheological responses by using Cox-Merz rule, and investigated the molecular structural and thermal effects on the solid-like and liquid-like behaviors of PFPEs. The temperature dependence of the endgroup agglomeration phenomena was examined, where the functional endgroups are decoupled as the temperature increases. By analyzing the relaxation processes, the molecular rheological studies will provide the optimal lubricant selection criteria to enhance the HDD performance and reliability for the heat-assisted magnetic recording applications.
Temperature dependence on the synthesis of Jatropha bio lubricant

International Nuclear Information System (INIS)

Gunam Resul, M.F.M.; Tinia Idaty Mohd Ghazi; Idris, A.

2009-01-01

Full text: Jatropha oil has good potential as the renewable energy as well as lubricant feedstock. The synthesis of jatropha bio lubricant was performed by transesterification of jatropha methyl ester (JME) with trimethyl-ol-propane (TMP) with sodium methoxide (NaOCH 3 ) catalyst. The effects of temperature on the synthesis were studied at a range between 120 degree Celsius and 200 degree Celsius with pressure kept at 10 mbar. The conversion of JME to jatropha bio lubricant was found to be the highest (47 %) at 200 degree Celsius. However, it was suggested that the optimum temperature of the reaction is at 150 degree Celsius due to insignificant improvement in bio lubricant production. To maintain forward reaction, the excess amount of JME was maintained at 3.9:1 ratios to TMP. Kinetic study was done and compared. The synthesis was found to follow a second order reaction with overall rate constant of 1.49 x 10 -1 (% wt/ wt.min.degree Celsius) -1 . The estimated activation energy was 3.94 kJ/mol. Pour point for jatropha bio lubricant was at -3 degree Celsius and Viscosity Index (VI) ranged from 178 to 183. The basic properties of jatropha bio lubricant, pour point and viscosities are found comparable to other plant based bio lubricant, namely palm oil and soybean based bio lubricant. (author)
Mechanical strength and thermophysical properties of PM212: A high temperature self-lubricating powder metallurgy composite

Science.gov (United States)

Edwards, Phillip M.; Sliney, Harold E.; Dellacorte, Christopher; Whittenberger, J. Daniel; Martineau, Robert R.

1990-01-01

A powder metallurgy composite, PM212, composed of metal bonded chromium carbide and solid lubricants is shown to be self-lubricating to a maximum application temperature of 900 C. The high temperature compressive strength, tensile strength, thermal expansion and thermal conductivity data needed to design PM212 sliding contact bearings and seals are reported for sintered and isostatically pressed (HIPed) versions of PM212. Other properties presented are room temperature density, hardness, and elastic modulus. In general, both versions appear to have adequate strength to be considered as sliding contact bearing materials, but the HIPed version, which is fully dense, is much stronger than the sintered version which contains about 20 percent pore volume. The sintered material is less costly to make, but the HIPed version is better where high compressive strength is important.
High-Performing, Low-Temperature-Operating, Long-Lifetime Aerospace Lubricants

Science.gov (United States)

Joshi, Prakash

2015-01-01

Long-duration space exploration will require spacecraft systems that can operate effectively over several years with minimal or no maintenance. Aerospace lubricants are key components of spacecraft systems. Physical Sciences Inc., has synthesized and characterized novel ionic liquids for use in aerospace lubricants that contribute to decreased viscosity, friction, and wear in aerospace systems. The resulting formulations offer low vapor pressure and outgassing properties and thermal stability up to 250 C. They are effective for use at temperatures as low as -70 C and provide long-term operational stability in aerospace systems. In Phase II, the company scaled several new ionic liquids and evaluated a novel formulation in a NASA testbed. The resulting lubricant compounds will offer lower volatility, decreased corrosion, and better tribological characteristics than standard liquid lubricants, particularly at lower temperatures.

Surface composition variation and high-vacuum performance of DLC/ILs solid-liquid lubricating coatings: Influence of space irradiation

International Nuclear Information System (INIS)

Liu Xiufang; Wang Liping; Pu Jibin; Xue Qunji

2012-01-01

In this paper, we fabricated a DLC/ionic liquid (DLC/ILs) solid-liquid lubricating coating and investigated the effect of atomic oxygen (AO), ultraviolet (UV), proton and electron irradiations on composition, structure, morphology and tribological properties of the DLC/ILs solid-liquid lubricating coatings. A ground-based simulation facility was employed to carry out the irradiation experiments. X-ray photoelectron spectroscope (XPS), Raman spectra, and Fourier Transform Infrared Spectroscopy (FTIR) were used to analyzed the structure and composition changes of DLC film and IL lubricant before and after irradiations. The tribological behavior of the DLC/ILs solid-liquid lubricating coating before and after irradiations was investigated by a vacuum tribometer with the pressure of 10 -5 Pa. The experimental results revealed that irradiations induced the structural changes, including oxidation, bond break and crosslinking reactions of DLC film and IL lubricant. The damage of proton and AO irradiations to lubricating materials were the most serious, and UV irradiation was the slightest. After irradiations, the friction coefficient of the solid-liquid lubricating coatings decreased (except for AO irradiation), but the disc wear rate increased compared with non-irradiation coatings.
Effectiveness of solid lubricant coatings for friction in hard vacuum (10-9 tor)

Science.gov (United States)

Verkin, B. I.; Lyubraskiy, I. M.; Udovenko, V. F.; Sentyurikhina, L. N.

1974-01-01

A study was made of the efficiency of solid lubricating coatings, based on MoS2 with various binders, during friction and under highvacuum conditions. Mass spectrometry was used for an analysis of the composition of the gas evolved from the coatings in the friction process. It is shown that the vacuum level, loading, and sliding velocity influence coating effectiveness. In the friction process the solid lubricant coatings yield characteristic decay products associated with the chemical nature of the binders. The mechanism of coating breakdown during friction is associated with the binder breakdown mechanism.
The Role of Solid Lubricants for Brake Friction Materials

Directory of Open Access Journals (Sweden)

Werner Österle

2016-02-01

Full Text Available This review article comprises of three parts. Firstly, reports of brake manufacturers on the beneficial impact of solid lubricants for pad formulations are surveyed. Secondly, since tribofilms were identified to play a crucial role in friction stabilization and wear reduction, the knowledge about tribofilm structures formed during automotive braking was reviewed comprehensively. Finally, a model for simulating the sliding behavior of tribofilms is suggested and a review on modelling efforts with different model structures related to real tribofilms will be presented. Although the variety of friction composites involved in commercial brake systems is very broad, striking similarities were observed in respect to tribofilm nanostructures. Thus, a generalization of the tribofilm nanostructure is suggested and prerequisites for smooth sliding performance and minimal wear rates have been identified. A minimum of 13 vol % of soft inclusions embedded in an iron oxide based tribofilm is crucial for obtaining the desired properties. As long as the solid lubricants or their reaction products are softer than magnetite, the main constituent of the tribofilm, the model predicts smooth sliding and minimum wear.
Improvement of wear-resistance of solid lubricants by ionic impact

DEFF Research Database (Denmark)

1993-01-01

A solid lubricating material, preferentially as a coating, deposited on a substrate surface by conventional technique such as dipping in a suspension, painting, or spraying is bombarded with energetic ions fron an ion accelerator or in a plasma discharge. By such a treatment the wear resistance o...
Pulsed Plasma Lubrication Device and Method

Science.gov (United States)

Hofer, Richard R. (Inventor); Bickler, Donald B. (Inventor); D'Agostino, Saverio A. (Inventor)

2016-01-01

Disclosed herein is a lubrication device comprising a solid lubricant disposed between and in contact with a first electrode and a second electrode dimensioned and arranged such that application of an electric potential between the first electrode and the second electrode sufficient to produce an electric arc between the first electrode and the second electrode to produce a plasma in an ambient atmosphere at an ambient pressure which vaporizes at least a portion of the solid lubricant to produce a vapor stream comprising the solid lubricant. Methods to lubricate a surface utilizing the lubrication device in-situ are also disclosed.
Analysis of hazardous organic residues from sodium hydrosulfite industry and utilization as raw materials in a novel solid lubricant production

International Nuclear Information System (INIS)

Shang, Jiwu; Zhang, Yihe; Zhou, Fengshan; Lv, Fengzhu; Han, Feng; Lu, Jinbo; Meng, Xianghai; Chu, Paul K.; Ye, Zhengfang; Xing, Jing

2011-01-01

Highlights: ► The hazardous organic residual wastes produced by the sodium hydrosulfite industry are analyzed and the main compounds are found to be thiodiglycol and 2,2′-dithiodiethanol. ► The lubricity of the organic residues is subsequently studied and the homemade solid lubricant is observed to have good lubricity. ► The clean process is expected to not only have commercial impact but also help to reduce environmental pollution. - Abstract: The hazardous organic residual wastes produced by the sodium hydrosulfite industry are demonstrated to be convertible into a novel solid lubricant. Identification and isolation of the organic residues are achieved by Fourier transform infrared (FTIR) spectroscopy, gas chromatography–mass spectrometry (GC–MS), and nuclear magnetic resonance (NMR). FTIR and GC–MS provide important information about the residues and the two main components obtained by column chromatography are further analyzed by NMR. The main organic residues are found to be thiodiglycol and 2,2′-dithiodiethanol which have potential applications in petroleum drilling because of their S–S and/or C–S functional groups. The lubricity of the organic residues is subsequently studied and the influence of different adsorbents on the lubricity is investigated and discussed. This homemade lubricant is observed to have good lubricity and by increasing the concentration of the commercial solid lubricant M, the lubricity diminishes. The process is expected to not only have commercial impact but also help to reduce environmental pollution.
Analysis of hazardous organic residues from sodium hydrosulfite industry and utilization as raw materials in a novel solid lubricant production

Energy Technology Data Exchange (ETDEWEB)

Shang, Jiwu [State Key Laboratory of Geological Processes and Mineral Resources, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences, Beijing 100083 (China); Zhang, Yihe, E-mail: zyh@cugb.edu.cn [State Key Laboratory of Geological Processes and Mineral Resources, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences, Beijing 100083 (China); Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Zhou, Fengshan; Lv, Fengzhu; Han, Feng; Lu, Jinbo; Meng, Xianghai [State Key Laboratory of Geological Processes and Mineral Resources, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences, Beijing 100083 (China); Chu, Paul K. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Ye, Zhengfang [Department of Environmental Engineering, Key Laboratory of Water and Sediment Sciences of the Ministry of Education, Peking University, Beijing 100871 (China); Xing, Jing [State Key Laboratory of Geological Processes and Mineral Resources, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences, Beijing 100083 (China)

2011-12-30

Highlights: Black-Right-Pointing-Pointer The hazardous organic residual wastes produced by the sodium hydrosulfite industry are analyzed and the main compounds are found to be thiodiglycol and 2,2 Prime -dithiodiethanol. Black-Right-Pointing-Pointer The lubricity of the organic residues is subsequently studied and the homemade solid lubricant is observed to have good lubricity. Black-Right-Pointing-Pointer The clean process is expected to not only have commercial impact but also help to reduce environmental pollution. - Abstract: The hazardous organic residual wastes produced by the sodium hydrosulfite industry are demonstrated to be convertible into a novel solid lubricant. Identification and isolation of the organic residues are achieved by Fourier transform infrared (FTIR) spectroscopy, gas chromatography-mass spectrometry (GC-MS), and nuclear magnetic resonance (NMR). FTIR and GC-MS provide important information about the residues and the two main components obtained by column chromatography are further analyzed by NMR. The main organic residues are found to be thiodiglycol and 2,2 Prime -dithiodiethanol which have potential applications in petroleum drilling because of their S-S and/or C-S functional groups. The lubricity of the organic residues is subsequently studied and the influence of different adsorbents on the lubricity is investigated and discussed. This homemade lubricant is observed to have good lubricity and by increasing the concentration of the commercial solid lubricant M, the lubricity diminishes. The process is expected to not only have commercial impact but also help to reduce environmental pollution.
Tribological properties and lubrication mechanism of in situ graphene-nickel matrix composite impregnated with lubricating oil

Science.gov (United States)

Lei, Yu; Du, Jinfang; Pang, Xianjuan; Wang, Haizhong; Yang, Hua; Jiang, Jinlong

2018-05-01

A solid-liquid synergetic lubricating system has been designed to develop a novel self-lubricating nickel matrix composite. The graphene-nickel (G-Ni) matrix composite with porous structure was fabricated by in situ growing graphene in bulk nickel using a powder metallurgy method. The porous structures of the composite were used to store polyalphaolefin (PAO) oil for self-lubricating. It is found that the G-Ni matrix composite under oil lubrication condition exhibited superior tribological properties as compared to pure nickel and the composite under dry sliding condition. The prestored oil was released from pores to the sliding surface forming a lubricating oil film during friction process. This lubricating oil film can protect the worn surface from severe oxidation, and help the formation and transfer of a carbon-based solid tribofilm derived from graphene and lubricating oil. This solid (graphene)-liquid (oil) synergistic lubricating mechanism is responsible for the reduction of friction coefficient and improvement of wear resistance of the in situ fabricated G-Ni matrix composite.
MoS2 solid-lubricating film fabricated by atomic layer deposition on Si substrate

Science.gov (United States)

Huang, Yazhou; Liu, Lei; Lv, Jun; Yang, Junjie; Sha, Jingjie; Chen, Yunfei

2018-04-01

How to reduce friction for improving efficiency in the usage of energy is a constant challenge. Layered material like MoS2 has long been recognized as an effective surface lubricant. Due to low interfacial shear strengths, MoS2 is endowed with nominal frictional coefficient. In this work, MoS2 solid-lubricating film was directly grown by atomic layer deposition (ALD) on Si substrate using MoCl5 and H2S. Various methods were used to observe the grown MoS2 film. Moreover, nanotribological properties of the film were observed by an atomic force microscope (AFM). Results show that MoS2 film can effectively reduce the friction force by about 30-45% under different loads, indicating the huge application value of the film as a solid lubricant. Besides the interlayer-interfaces-sliding, the smaller capillary is another reason why the grown MoS2 film has smaller friction force than that of Si.
Elasto-hydrodynamic lubrication

CERN Document Server

Dowson, D; Hopkins, D W

1977-01-01

Elasto-Hydrodynamic Lubrication deals with the mechanism of elasto-hydrodynamic lubrication, that is, the lubrication regime in operation over the small areas where machine components are in nominal point or line contact. The lubrication of rigid contacts is discussed, along with the effects of high pressure on the lubricant and bounding solids. The governing equations for the solution of elasto-hydrodynamic problems are presented.Comprised of 13 chapters, this volume begins with an overview of elasto-hydrodynamic lubrication and representation of contacts by cylinders, followed by a discussio
Investigation of the effect of engine lubricant oil on remote temperature sensing using thermographic phosphors

Energy Technology Data Exchange (ETDEWEB)

Abou Nada, Fahed, E-mail: Fahed.Abou_Nada@forbrf.lth.se; Aldén, Marcus; Richter, Mattias

2016-11-15

Phosphor thermometry, a remote temperature sensing technique, is widely implemented to measure the temperature of different combustion engines components. The presence of engine lubricant can influence the behavior of the applied sensor materials, known as thermographic phosphors, and thus leading to erroneous temperature measurements. The effect of two engine lubricants on decay times originating from six different thermographic phosphors was investigated. The decay time of each thermographic phosphor was investigated as a function of lubricant/phosphor mass ratio. Tests were conducted at temperatures around 293 K and 376 K for both lubricants. The investigations revealed that ZnO:Zn and ZnS:Ag are the only ones that exhibit a change of the decay time as function of the lubricant/phosphor mass ratio. While the remaining thermographic phosphors, namely BaMg{sub 2}Al{sub 16}O{sub 27}:Eu (BAM), Al{sub 2}O{sub 3}-coated BaMg{sub 2}Al{sub 16}O{sub 27}:Eu, La{sub 2}O{sub 2}S:Eu, Mg{sub 3}F{sub 2}GeO{sub 4}:Mn, displayed no sensitivity of their characteristic decay time on to the presence of lubricant on the porous coating. Biases in the calculated temperature are to be expected if the utilized thermographic phosphor displays decay time sensitivity to the existence of the engine lubricant within the sensor. Such distortions are concealed and can occur undetected leading to false temperature readings for the probed engine component.
Tribological properties of solid lubricants filled glass fiber reinforced polyamide 6 composites

International Nuclear Information System (INIS)

Li, Du-Xin; You, Yi-Lan; Deng, Xin; Li, Wen-Juan; Xie, Ying

2013-01-01

Highlights: ► The tribological properties of GF/PA6 improved by the incorporation of PTFE. ► PTFE and UHMWPE exhibited a synergism effect on reducing friction coefficient. ► Solid lubricants enlarged the range of applied velocity for GF/PA6 composite. - Abstract: The main purpose of this paper is to further optimize the tribological properties of the glass fiber reinforced PA6 (GF/PA6,15/85 by weight) for high performance friction materials using single or combinative solid lubricants such as Polytetrafluroethylene (PTFE), ultra-high molecular weight polyethylene (UHMWPE) and the combination of both of them. Various polymer blends, where GF/PA6 acts as the polymer matrix and solid lubricants as the dispersed phase were prepared by injection molding. The tribological properties of these materials and the synergism as a result of the incorporation of both PTFE and UHMWPE were investigated. The results showed that, at a load of 40 N and a velocity of 200 rpm, PTFE was effective in improving the tribological capabilities of matrix material. On the contrary, UHMWPE was not conductive to maintain the structure integrity of GF/PA6 composite and harmful to the friction and wear properties. The combination of PTFE and UHMWPE showed synergism on further reducing the friction coefficient of the composites filled with either PTFE or UHMWPE only. Effects of load and velocity on tribological behavior were also discussed. To further understand the wear mechanism, the worn surfaces were examined by scanning electron microscopy
Study of solid lubrication with MoS2 coating in the presence of ...

Indian Academy of Sciences (India)

Molybdenum disulphide (MoS2) based solid lubricant mixtures con- taining zirconia and ... age during relative movement and to reduce friction and wear. ..... In this hexagonal structure the bonds between the carbon atoms in a layer are strong.
Thermal Processing Effects on the Adhesive Strength of PS304 High Temperature Solid Lubricant Coatings

Science.gov (United States)

DellaCorte, Christopher; Edmonds, Brian J.; Benoy, Patricia A.

2001-01-01

In this paper the effects of post deposition heat treatments on the cohesive and adhesive strength properties of PS304, a plasma sprayed nickel-chrome based, high temperature solid lubricant coating deposited on stainless steel, are studied. Plasma spray deposited coating samples were exposed in air at temperatures from 432 to 650 C for up to 500 hr to promote residual stress relief, enhance particle to particle bonding and increase coating to substrate bond strength. Coating pull-off strength was measured using a commercial adhesion tester that utilizes 13 mm diameter aluminum pull studs attached to the coating surface with epoxy. Pull off force was automatically recorded and converted to coating pull off strength. As deposited coating samples were also tested as a baseline. The as-deposited (untreated) samples either delaminated at the coating-substrate interface or failed internally (cohesive failure) at about 17 MPa. Samples heat treated at temperatures above 540 C for 100 hr or at 600 C or above for more than 24 hr exhibited strengths above 31 MPa, nearly a two fold increase. Coating failure occurred inside the body of the coating (cohesive failure) for nearly all of the heat-treated samples and only occasionally at the coating substrate interface (adhesive failure). Metallographic analyses of heat-treated coatings indicate that the Nickel-Chromium binder in the PS304 appears to have segregated into two phases, a high nickel matrix phase and a high chromium precipitated phase. Analysis of the precipitates indicates the presence of silicon, a constituent of a flow enhancing additive in the commercial NiCr powder. The exact nature and structure of the precipitate phase is not known. This microstructural change is believed to be partially responsible for the coating strength increase. Diffusion bonding between particles may also be playing a role. Increasing the heat treatment temperature, exposure time or both accelerate the heat treatment process. Preliminary
Oil and natural gas technology review-lubrication and lubricants

Energy Technology Data Exchange (ETDEWEB)

Moos, J

1966-01-01

A summary is presented of the advances made during 1967 in the following areas: production and transmission of natural gas; geosciences; drilling and production technology; secondary recovery; transportation by tanker, pipelines, and tank cars; storage; planning of refineries; control and automation; cracking and gasification of crude oil; separation and hydrogenation processes; petrochemicals; combustion technology; fuels and additives; air and water pollution control; production of lubricants; lubrication with mist, gas, and vapors; hydraulic fluids; lubricant additives; oxidation and aging of oils; greases; solid lubricants; bearings; machining; friction and wear; and changes in materials of construction. (220 refs.)
Numerical analysis of all flow state lubrication performance of water-lubricated thrust bearing

International Nuclear Information System (INIS)

Deng Xiao; Deng Liping; Huang Wei; Liu Lizhi; Zhao Xuecen; Liu Songya

2015-01-01

A model enabling all different flow state lubrication performance simulation and analysis for water-lubricated thrust bearing is presented, considering the temperature influence and elastic deformation. Lubrication state in the model is changed directly from laminar lubrication to turbulent lubrication once Reynolds number exceeds the critical Reynolds number. The model is numerically solved and results show that temperature variation is too little to influence the lubrication performance; the elastic deformation can slightly reduce the load carrying capacity of the thrust bearing; and the turbulent lubrication can remarkably improve the load carrying capacity. (authors)
Prediction of the viscosity of lubricating oil blends at any temperature

Energy Technology Data Exchange (ETDEWEB)

Diaz, R.M.; Bernardo, M.I.; Fernandez, A.M.; Folgueras, M.B. [University of Oviedo, Oveido (Spain). Dept. of Energy

1996-04-01

This paper discusses a method of predicting the viscosity of multicomponent base lubricating oil mixtures based on Andrade`s equation. The kinematic viscosity of three types of base lubricating oils and their binary and ternary mixtures were measured at different temperatures and the parameters of Andrade`s equation were calculated. The results obtained indicate that the Andrade parameters vary linearly with the mixture composition. From these linear equations, generalized mixing equations are derived which confirm the experimental results. By application of the mixing equations, a simple method is obtained for prediction of the viscosity of oil blends at any temperature from viscosity-temperature data of the oil components. The calculated viscosities gave an average absolute deviation of 10% over the temperature range 20-100{degree}C. 8 refs., 3 figs., 4 tabs.
The effect of surface roughness on the adhesion of solid surfaces for systems with and without liquid lubricant

DEFF Research Database (Denmark)

Samoilov, V. N.; Sivebæk, Ion Marius; Persson, B. N. J.

2004-01-01

We present molecular dynamics results for the interaction between two solid elastic walls during pull-off for systems with and without octane (C8H18) lubricant. We used two types of substrate-flat and corrugated-and varied the lubricant coverage from similar to1/8 to similar to4 ML (monolayers...
On the combined effect of lubrication and compaction temperature on properties of iron-based P/M parts

International Nuclear Information System (INIS)

Babakhani, Abolfazl; Haerian, Ali; Ghambari, Mohammad

2006-01-01

Addition of lubricant in the form of admixed with powder reduces friction between die wall and powder during compaction of P/M parts. However, it has detrimental effect on mechanical properties. On the other hand, warm compaction of powders improves density and hence, the mechanical properties of these parts. Die wall lubrication can be used along with warm compaction to avoid the disadvantages of the admixed lubricant while reducing the friction, and benefiting the advantages of warm compaction. In this study, the combined effect of warm compaction and die wall lubrication with various amounts of admixed lubricant has been examined. Compacts were made of admixed powders containing from 0 to 0.6% lithium stearate with the die wall lubricated by 1.5% emulsion of lithium stearate under two different pressing pressures of 500 and 650 MPa. The temperatures used were: RT, 130, 150 and 165 deg. C. It was found out that at both compaction pressures, reduction of admixed lubricant down to 0% increased the green density and mechanical properties of the sintered parts. For samples pressed at 500 and 650 MPa the increase in green density due to elimination of admixed lubricant and using die wall lubrication was 0.33 and 0.35 g/cm 3 , respectively. It was also found out that die wall lubrication is more effective in increasing green density at higher compaction pressures. Sinter density and mechanical properties increased by increasing compaction temperature up to 150 deg. C. Both parameters were deteriorated above this temperature for admixed powders, while it kept increasing for die wall lubrication
Preliminary Evaluation of PS300: A New Self-Lubricating High Temperature Composite Coating for Use to 800 C

Science.gov (United States)

Dellacorte, C.; Edmonds, B. J.

1995-01-01

This paper introduces PS300, a plasma sprayed, self-lubricating composite coating for use in sliding contacts at temperatures to 800 C. PS300 is a metal bonded chrome oxide coating with silver and BaF2/CaF2 eutectic solid lubricant additives. PS300 is similar to PS200, a chromium carbide based coating, which is currently being investigated for a variety of tribological applications. In pin-on-disk testing up to 650 C, PS300 exhibited comparable friction and wear properties to PS200. The PS300 matrix, which is predominantly chromium oxide rather than chromium carbide, does not require diamond grinding and polishes readily with silicon carbide abrasives greatly reducing manufacturing costs compared to PS200. It is anticipated that PS300 has potential for sliding bearing and seal applications in both aerospace and general industry.

Towards green lubrication in machining

CERN Document Server

Liew Yun Hsien, Willey

2014-01-01

The book gives an overview of environmental friendly gaseous and vapour, refrigerated compressed gas, solid lubricant, mist lubrication, minimum quantity lubrication (MQL) and vegetable oils that can be used as lubricants and additives in industrial machining applications. This book introduces vegetable oils as viable and good alternative resources because of their environmental friendly, non-toxic and readily biodegradable nature. The effectiveness of various types of vegetables oils as lubricants and additives in reducing wear and friction is discussed in this book. Engineers and scientist working in the field of lubrication and machining will find this book useful.
Bio-lubricants derived from waste cooking oil with improved oxidation stability and low-temperature properties.

Science.gov (United States)

Li, Weimin; Wang, Xiaobo

2015-01-01

Waste cooking oil (WCO) was chemically modified via epoxidation using H2O2 followed by transesterification with methanol and branched alcohols (isooctanol, isotridecanol and isooctadecanol) to produce bio-lubricants with improved oxidative stability and low temperature properties. Physicochemical properties of synthesized bio-lubricants such as pour point (PP), cloud point (CP), viscosity, viscosity index (VI), oxidative stability, and corrosion resistant property were determined according to standard methods. The synthesized bio-lubricants showed improved low temperature flow performances compared with WCO, which can be attributing to the introduction of branched chains in their molecular structures. What's more, the oxidation stability of the WCO showed more than 10 folds improvement due to the elimination of -C=C-bonds in the WCO molecule. Tribological performances of these bio-lubricants were also investigated using four-ball friction and wear tester. Experimental results showed that derivatives of WCO exhibited favorable physicochemical properties and tribological performances which making them good candidates in formulating eco-friendly lubricants.
Influence of load and sliding velocity on wear resistance of solid-lubricant composites of ultra-high molecular weight polyethylene

Science.gov (United States)

Panin, S. V.; Kornienko, L. A.; Buslovich, D. G.; Alexenko, V. O.; Ivanova, L. R.

2017-12-01

To determine the limits of the operation loading intervals appropriate for the use of solid lubricant UHMWPE composites in tribounits for mechanical engineering and medicine, the tribotechnical properties of UHMWPE blends with the optimum solid lubricant filler content (polytetrafluoroethylene, calcium stearate, molybdenum disulfide, colloidal graphite, boron nitride) are studied under dry sliding friction at different velocities (V = 0.3 and 0.5 m/s) and loads (P = 60 and 140 N). It is shown that the wear resistance of solid lubricant UHMWPE composites at moderate sliding velocities (V = 0.3 m/s) and loads (P = 60 N) increases 2-3 times in comparison with pure UHMWPE, while at high load P = 140 N wear resistance of both neat UHMWPE and its composites is reduced almost twice. At high sliding velocities and loads (up to P = 140 N), multiple increasing of the wear of pure UHMWPE and its composites takes place (by the factor of 5 to 10). The operational conditions of UHMWPE composites in tribounits in engineering and medicine are discussed.
Prediction method for the lubricating oil temperature of manual transaxle; Manual transaxle no yuon yosoku simulation

Energy Technology Data Exchange (ETDEWEB)

Iritani, M; Kaneda, K; Ibaraki, K [Toyota Central Research and Development Labs., Inc., Aichi (Japan); Suzuki, K; Morita, Y [Toyota Motor Corp., Aichi (Japan)

1997-10-01

Heat transfer and flow characteristics in manual transaxle (MT) are not clear. The measurement of the heat flux and the heat generations and the flow visualization were conducted for quantitative analysis of the heat transfer phenomena in the MT. A simulating technique for the lubricant temperature was developed with these experimental data and the prediction accuracy was within 3degC under the various operating conditions. The simulation was verified to be useful for estimating the lubricant temperature reduction by the lubricant volume reduction, air flow improvement around MT, etc. 7 refs., 8 figs.
A comparison of the performance of solid and liquid lubricants in oscillating spacecraft ball bearings

Science.gov (United States)

Gill, S.

1994-01-01

The European Space Tribology Laboratory (ESTL) has been engaged in a program to compare the performance of oscillating ball bearings when lubricated by a number of space lubricants, both liquid and solid. The results have shown that mean torque levels are increased by up to a factor of five above the normal running torque, and that often torque peaks of even greater magnitudes are present at the ends of travel. It is believed that these effects are caused by a build-up of compacted debris in the contact zone, thus reducing the ball/race conformity ratio.
Composite Coatings with Ceramic Matrix Including Nanomaterials as Solid Lubricants for Oil-Less Automotive Applications

Directory of Open Access Journals (Sweden)

Posmyk A.

2016-06-01

Full Text Available The paper presents the theoretical basis of manufacturing and chosen applications of composite coatings with ceramic matrix containing nanomaterials as a solid lubricant (AHC+NL. From a theoretical point of view, in order to reduce the friction coefficient of sliding contacts, two materials are required, i.e. one with a high hardness and the other with low shear strength. In case of composite coatings AHC+NL the matrix is a very hard and wear resistant anodic oxide coating (AHC whereas the solid lubricant used is the nanomaterial (NL featuring a low shear strength such as glassy carbon nanotubes (GC. Friction coefficient of cast iron GJL-350 sliding against the coating itself is much higher (0.18-0.22 than when it slides against a composite coating (0.08-0.14. It is possible to reduce the friction due to the presence of carbon nanotubes, or metal nanowires.
Development of high performance lubricant through the compatibility of polyalphaolefin, polyurea and irradiated polytetrafluoroethylene

International Nuclear Information System (INIS)

Ratao, Natalia Torres

2013-01-01

Lubricants are gaseous, liquid, semi solid or solid (powder) materials those form a film between two parties preventing friction. High performance lubricants are designed to work under severe conditions of temperature, pressure, and contamination. The most used are liquids (oils) and semi solids (greases). Greases are applied where oils can drain or in inaccessible places and are divided generally into two classes, soap and no soap. The most used non soap grease is polyurea, obtained by the reaction between amine and isocyanate, has highly thixotropic, high dielectric strength and excellent anticorrosive property, so it is widely used for lubrication of electric motors and shipbuilding machinery. For a grease with high performance, in this study was used a synthetic lubricant fluid, polyalphaolefin, and was also employed solid lubricant additive polytetrafluoroethylene (PTFE) due its lowest coefficient of friction, is found commercially irradiated in air to obtain smaller particles and to produce oxygenated terminal groups those are more compatible with the metal surface. The tests conducted were comparatively between pure polyurea grease and with PTFE additive. The characterizations were made by infrared spectroscopy and elemental analysis of C, N and H and Free NCO index, proving the formation of four carbons polyurea (tetraurea). The functional analysis of drop point and oil separation showed high stability and compatibility between the polymers increased when PTFE was added. The excellent resistance of pure tetraurea grease to wear and extreme pressure were demonstrated by four-ball and practical bearings tests, characterizing this grease as a high performance lubricant, when compared to most used greases in the market. (author)
Preliminary evaluation of PS300: A new self-lubricating high temperature composite coating for use to 800{degrees}C

Energy Technology Data Exchange (ETDEWEB)

DellaCorte, C.; Edmonds, B.J.

1996-12-31

This paper introduces PS300, a plasma sprayed, self-lubricating composite coating for use in sliding contacts at temperatures to 800{degrees}C. PS300 is a metal bonded chrome oxide coating with silver and BaF{sub 2}/CaF{sub 2} eutectic solid lubricant additives. PS300 is similar to PS200, a chromium carbide based coating; which is currently being investigated for a variety of tribological applications. In pin-on-disk testing up to 650{degrees}C, PS300 exhibited comparable friction and wear properties to PS200. The PS300 matrix, which is predominantly chromium oxide rather than chromium carbide, does not require diamond grinding and polishes readily with silicon carbide abrasives greatly reducing manufacturing costs compared to PS200. It is anticipated that PS300 has potential for sliding bearing and seal applications in both aerospace and general industry.
Solid Lubrication of Laser Deposited Carbon Nanotube Reinforced Nickel Matrix Nanocomposites Preprint

Science.gov (United States)

2009-03-01

thickness 440C stainless steel (SS) and the deposited composites had a square geometry in order to assure a uniform laser heat distribution during the...tested against (a) 440C stainless steel counterface with Pmax=0.6 GPa and (b) Si3N4 counterface with Pmax=0.8 GPa. Fig. 4. (a) Pure Ni and (c...decrease in friction coefficients compared to pure Ni. 15. SUBJECT TERMS Tribology , friction, wear, solid lubricant, carbon nanotubes, metal
Additives for high-temperature liquid lubricants

Science.gov (United States)

Lawton, Emil A.; Yavrouian, Andre H.; Repar, John

1988-01-01

A preliminary research program was conducted to demonstrate a new concept for additives to liquid lubricants. It was demonstrated that suspensions of o-phthalonitrile and a substituted 1,2-maleonitrile in mineral oil and dilute solutions of o-phthalonitrile and tetrafluoro-o-phthalonitrile extended the lifetime of bearings under boundary lubricating conditions. The solutions exhibited coefficients of friction under high loads of 0.02-0.03. These results were consistent with the hypothesis that these compounds react with the hot metal surface to form a planar lubricating film by means of a metal or metal oxide template reaction. Also, the adherence was very strong due to the chelating action of the planar macrocycles postulated to form under the experimental conditions.
Synthetic lubricating oils

Energy Technology Data Exchange (ETDEWEB)

Rodriguez Jurado, J

1953-01-01

A yellow solid petroleum paraffin d/sup 60/ 0.808, I number 3.5, average molecular weight 350, chlorinated and condensed with benzene, xylene, or naphthalene by the Friedel and Crafts reaction, in the presence of anhydrous AlCl/sub 3/ or activated Al, gave synthetic lubricating oils. Xylene was the preferred aromatic compound, naphthalene required the use of less completely chlorinated paraffin, benzene produced resins difficult to remove and gave darker oils with excessive green fluorescence. Activated Al rather than anhydrous AlCl/sub 3/ gave darker oils with higher viscosity and Conradson C values. Tar from the low-temperature distillation of lignite, used as a source of a paraffin fraction melting 40/sup 0/ to 48/sup 0/ (chlorinated to 26.5 percent Cl) and an aromatic fraction, 45 percent aromatic compounds by volume (mainly polysubstituted benzenes), I number 10, was converted to a similar synthetic lubricant with the following properties: Kinematic viscosity at 210/sup 0/ F., 50.4 centistokes; viscosity index, 92; Conradson C, 1.5 percent; solidification point, 9/sup 0/; S, 0.41 percent.
The Preparation and Performances of Self-Dispersed Nanomicron Emulsified Wax Solid Lubricant Ewax for Drilling Fluids

Directory of Open Access Journals (Sweden)

Feng-shan Zhou

2014-01-01

Full Text Available An oil-in-water nanomicron wax emulsion with oil phase content 45 wt% was prepared by using the emulsifying method of surfactant-in-oil. The optimum prepared condition is 85°C, 20 min, and 5 wt% complex emulsifiers. Then the abovementioned nanomicron emulsifying wax was immersed into a special water-soluble polymer in a certain percentage by the semidry technology. At last, a solidified self-dispersed nanomicron emulsified wax named as Ewax, a kind of solid lubricant for water based drilling fluid, was obtained after dried in the special soluble polymer containing emulsifying wax in low temperature. It is shown that the adhesion coefficient reduced rate (ΔKf is 73.5% and the extreme pressure (E-P friction coefficient reduced rate (Δf is 77.6% when the produced Ewax sample was added to fresh water based drilling fluid at dosage 1.0 wt%. In comparison with other normal similar liquid products, Ewax not only has better performances of lubrication, filtration loss control property, heat resistance, and tolerance to salt and is environmentally friendly, but also can solve the problems of freezing in the winter and poor storage stability of liquid wax emulsion in oilfield applications.
Origins of extreme boundary lubrication by phosphatidylcholine liposomes.

Science.gov (United States)

Sorkin, Raya; Kampf, Nir; Dror, Yael; Shimoni, Eyal; Klein, Jacob

2013-07-01

Phosphatidylcholine (PC) vesicles have been shown to have remarkable boundary lubricating properties under physiologically-high pressures. Here we carry out a systematic study, using a surface force balance, of the normal and shear (frictional) forces between two opposing surfaces bearing different PC vesicles across water, to elucidate the origin of these properties. Small unilamellar vesicles (SUVs, diameters < 100 nm) of the symmetric saturated diacyl PCs DMPC (C(14)), DPPC (C(16)) and DSPC (C(18)) attached to mica surfaces were studied in their solid-ordered (SO) phase on the surface. Overall liposome lubrication ability improves markedly with increasing acyl chain length, and correlates strongly with the liposomes' structural integrity on the substrate surface: DSPC-SUVs were stable on the surface, and provided extremely efficient lubrication (friction coefficient μ ≈ 10(-4)) at room temperature at pressures up to at least 18 MPa. DMPC-SUVs ruptured following adsorption, providing poor high-pressure lubrication, while DPPC-SUVs behavior was intermediate between the two. These results can be well understood in terms of the hydration-lubrication paradigm, but suggest that an earlier conjecture, that highly-efficient lubrication by PC-SUVs depended simply on their being in the SO rather than in the liquid-disordered phase, should be more nuanced. Our results indicate that the resistance of the SUVs to mechanical deformation and rupture is the dominant factor in determining their overall boundary lubrication efficiency in our system. Copyright © 2013 Elsevier Ltd. All rights reserved.
RADIAL FORCE IMPACT ON THE FRICTION COEFFICIENT AND TEMPERATURE OF A SELF-LUBRICATING PLAIN BEARING

Directory of Open Access Journals (Sweden)

Nada Bojić

2017-12-01

Full Text Available Self-lubricating bearings are available in spherical, plain, flanged journal, and rod end bearing configurations. They were originally developed to eliminate the need for re-lubrication, to provide lower torque and to solve application problems where the conventional metal-to-metal bearings would not perform satisfactorily, for instance, in the presence of high frequency vibrations. Among the dominant tribological parameters of the self-lubricating bearing, two could be singled out: the coefficient of friction and temperature. To determine these parameters, an experimental method was applied in this paper. By using this method, the coefficient of friction and temperature were identified and their correlation was established. The aim of this research was to determine the effect of radial force on tribological parameters in order to predict the behavior of sliding bearings with graphite in real operating conditions.
Tribological performance of Zinc soft metal coatings in solid lubrication

Science.gov (United States)

Regalla, Srinivasa Prakash; Krishnan Anirudh, V.; Reddy Narala, Suresh Kumar

2018-04-01

Solid lubrication by soft coatings is an important technique for superior tribological performance in machine contacts involving high pressures. Coating with soft materials ensures that the subsurface machine component wear decreases, ensuring longer life. Several soft metal coatings have been studied but zinc coatings have not been studied much. This paper essentially deals with the soft coating by zinc through electroplating on hard surfaces, which are subsequently tested in sliding experiments for tribological performance. The hardness and film thickness values have been found out, the coefficient of friction of the zinc coating has been tested using a pin on disc wear testing machine and the results of the same have been presented.
Squeezing molecular thin alkane lubrication films between curved solid surfaces with long-range elasticity: Layering transitions and wear

DEFF Research Database (Denmark)

Sivebæk, Ion Marius; Samoilov, V. N.; Persson, B. N. J.

2003-01-01

The properties of alkane lubricants confined between two approaching solids are investigated by a model that accounts for the curvature and the elastic properties of the solid surfaces. We consider linear alkane molecules of different chain lengths, C3H8, C4H10, C8H18, C9H20, C10H22, C12H26 and C14...
Tribological and Mechanical Behaviors of Polyamide 6/Glass Fiber Composite Filled with Various Solid Lubricants

Directory of Open Access Journals (Sweden)

Duxin Li

2013-01-01

Full Text Available The effects of polytetrafluoroethylene (PTFE, graphite, ultrahigh molecular weight polyethylene (UHMWPE, and their compounds on mechanical and tribological properties of glass-fiber-reinforced polyamide 6 (PA6/GF were studied. The polymeric materials were blended using twin-screw extruder and subsequently injection molded for test samples. Mechanical properties were investigated in terms of hardness, tensile strength, and impact strength. Friction and wear experiments were run under ambient conditions at a rotating speed of 200 rpm and load of 100 N. The morphologies of the worn surfaces were also observed with scanning electron microscope. The results showed that graphite could increase the tensile strength of PA6/GF-15 composite, but the material became soft. Graphite/UHMWPE complex solid lubricants were effective in increasing the already high impact strength of PA6/GF-15 composite. 5% PTFE gave the maximum reduction in the coefficient of friction. However, PTFE/UHMWPE complex solid lubricants were the best choice for improving both friction and wear behaviors due to the lower friction coefficient and mass wear rate. Moreover, the worn surface of PA6 composites revealed that adhesive wear, abrasive wear, and fatigue wear occurred in this study.
Tribological and mechanical behaviors of polyamide 6/glass fiber composite filled with various solid lubricants.

Science.gov (United States)

Li, Duxin; Xie, Ying; Li, Wenjuan; You, Yilan; Deng, Xin

2013-01-01

The effects of polytetrafluoroethylene (PTFE), graphite, ultrahigh molecular weight polyethylene (UHMWPE), and their compounds on mechanical and tribological properties of glass-fiber-reinforced polyamide 6 (PA6/GF) were studied. The polymeric materials were blended using twin-screw extruder and subsequently injection molded for test samples. Mechanical properties were investigated in terms of hardness, tensile strength, and impact strength. Friction and wear experiments were run under ambient conditions at a rotating speed of 200 rpm and load of 100 N. The morphologies of the worn surfaces were also observed with scanning electron microscope. The results showed that graphite could increase the tensile strength of PA6/GF-15 composite, but the material became soft. Graphite/UHMWPE complex solid lubricants were effective in increasing the already high impact strength of PA6/GF-15 composite. 5% PTFE gave the maximum reduction in the coefficient of friction. However, PTFE/UHMWPE complex solid lubricants were the best choice for improving both friction and wear behaviors due to the lower friction coefficient and mass wear rate. Moreover, the worn surface of PA6 composites revealed that adhesive wear, abrasive wear, and fatigue wear occurred in this study.
Tribological Performance of M50-Ag-TiC Self-Lubricating Composites at Elevated Temperature

Science.gov (United States)

Zhou, Hongyan; Shi, Xiaoliang; Huang, Yuchun; Liu, Xiyao; Li, Ben

2018-05-01

M50 steel is widely used in aero-engine bearings and other high-temperature bearings. However, the poor wear of M50 steel resistance restrains its further applications. In this paper, the sliding tribological behaviors of M50 steel, M50-Ag composites (MAC) and M50-Ag-TiC composites (MATC) against Si3N4 ball were investigated from 150 to 600 °C at 15 N-0.2 m/s. MATC showed better tribological properties in comparison with M50 and MAC. Especially at 450 °C, MATC obtained the lowest friction coefficient of 0.15 and smallest wear rate of 1.3 × 10-5 mm3 N-1 m-1. The excellent tribological performance of MATC during the friction test was attributed to the continuous lubricating film containing lubricant Ag and reinforcement TiC, as well as the subsurface compacted layer that could well support the lubricating film to prevent it from being destroyed. At 600 °C, because of the tribo-chemical reaction between Ag and Mo oxide during sliding process, the newly formed Ag2MoO4 lubricating film was well spread out on the friction surface, which could continuously improve the tribological behavior of MATC. This investigation was meaningful to improve the anti-friction and wear resistance of M50 matrix bearing over a wide temperature range.
Mechanics of a gaseous film barrier to lubricant wetting of elastohydrodynamically lubricated conjunctions

Science.gov (United States)

Prahl, J. M.; Hamrock, B. J.

1985-01-01

Two analytical models, one based on simple hydrodynamic lubrication and the other on soft elastohydrodynamic lubrication, are presented and compared to delineate the dominant physical parameters that govern the mechanics of a gaseous film between a small droplet of lubricant and the outer race of a ball bearing. Both models are based on the balance of gravity forces, air drag forces, and air film lubrication forces and incorporate a drag coefficient C sub D and a lubrication coefficient C sub L to be determined from experiment. The soft elastohydrodynamic lubrication (EHL) model considers the effects of droplet deformation and solid-surface geometry; the simpler hydrodynamic lubrication (HL) model assumes that the droplet remains essentially spherical. The droplet's angular position depended primarily on the ratio of gas inertia to droplet gravity forces and on the gas Reynolds number and weakly on the ratio of droplet gravity forces to surface tension forces (Bond number) and geometric ratios for the soft EHL. An experimental configuration in which an oil droplet is supported by an air film on the rotating outer race of a ball bearing within a pressure-controlled chamber produced measurements of droplet angular position as a function of outer-race velocity droplet size and type, and chamber pressure.

Potential of Palm Olein as Green Lubricant Source: Lubrication Analysis and Chemical Characterisation

International Nuclear Information System (INIS)

Darfizzi Derawi; Jumat Salimon

2014-01-01

Palm olein (PO o ) is widely used as edible oil in tropical countries. The lubrication properties and chemical compositions of PO o being considered to be used as renewable raw material for bio lubricant synthesis. PO o is suitable to be used directly as bio lubricant for medium temperature industrial applications. Palm olein has good viscosity index, oxidative stability, flash and fire point as a lubricant source. PO o contains unsaturated triacylglycerols (TAG): Palmitin-Olein-Olein, POO (33.3 %), Palmitin-Olein-Palmitin, POP (29.6 %), which are very important to produce good lubricant properties. This unsaturated bond is preferable in chemical modification to produce bio lubricant. The chemical compositions of PO o were tested by using high performance liquid chromatography (HPLC) and gas chromatography (GC) techniques. (author)
Experimental investigations on the effect of process parameters with the use of minimum quantity solid lubrication in turning

Science.gov (United States)

Makhesana, Mayur A.; Patel, K. M.; Mawandiya, B. K.

2018-04-01

Turning process is a very basic process in any field of mechanical application. During turning process, most of the energy is converted into heat because of the friction between work piece and tool. Heat generation can affect the surface quality of the work piece and tool life. To reduce the heat generation, Conventional Lubrication process is used in most of the industry. Minimum quantity lubrication has been an effective alternative to improve the performance of machining process. In this present work, effort has been made to study the effect of various process parameters on the surface roughness and power consumption during turning of EN8 steel material. Result revealed the effect of depth of cut and feed on the obtained surface roughness value. Further the effect of solid lubricant has been also studied and optimization of process parameters is also done for the turning process.
Tribological Properties of New Cu-Al/MoS2 Solid Lubricant Coatings Using Magnetron Sputter Deposition

Directory of Open Access Journals (Sweden)

Ming Cao

2018-04-01

Full Text Available The increasing demands of environmental protection have led to solid lubricant coatings becoming more and more important. A new type of MoS2-based coating co-doped with Cu and Al prepared by magnetron sputtering, including Cu/MoS2 and Cu-Al/MoS2 coatings, for lubrication applications is reported. To this end, the coatings were annealed in an argon atmosphere furnace. The microstructure and the tribological properties of the coatings prior to and following annealing were analyzed using scanning electron microscopy, energy dispersive spectrometry, X-ray diffractometry (XRD and with a multi-functional tester for material surface properties. The results demonstrated that the friction coefficient of the Cu/MoS2 coating was able to reach as low as 0.07, due to the synergistic lubrication effect of the soft metal Cu with MoS2. However, the wear resistance of the coating was not satisfied. Although the lowest friction coefficient of the Cu-Al/MoS2 coatings was 0.083, the wear resistance was enhanced, which was attributed to the improved the toughness of the coatings due to the introduction of aluminum. The XRD results revealed that the γ2-Cu9Al4 phase was formed in the specimen of Cu-Al/MoS2 coatings. The comprehensive performance of the Cu-Al/MoS2 coatings after annealing was improved in comparison to substrate heating, since the heat-treatment was beneficial for the strengthening of the solid solution of the coatings.
Influence of lubrication forces in direct numerical simulations of particle-laden flows

Science.gov (United States)

Maitri, Rohit; Peters, Frank; Padding, Johan; Kuipers, Hans

2016-11-01

Accurate numerical representation of particle-laden flows is important for fundamental understanding and optimizing the complex processes such as proppant transport in fracking. Liquid-solid flows are fundamentally different from gas-solid flows because of lower density ratios (solid to fluid) and non-negligible lubrication forces. In this interface resolved model, fluid-solid coupling is achieved by incorporating the no-slip boundary condition implicitly at particle's surfaces by means of an efficient second order ghost-cell immersed boundary method. A fixed Eulerian grid is used for solving the Navier-Stokes equations and the particle-particle interactions are implemented using the soft sphere collision and sub-grid scale lubrication model. Due to the range of influence of lubrication force on a smaller scale than the grid size, it is important to implement the lubrication model accurately. In this work, different implementations of the lubrication model on particle dynamics are studied for various flow conditions. The effect of a particle surface roughness on lubrication force and the particle transport is also investigated. This study is aimed at developing a validated methodology to incorporate lubrication models in direct numerical simulation of particle laden flows. This research is supported from Grant 13CSER014 of the Foundation for Fundamental Research on Matter (FOM), which is part of the Netherlands Organisation for Scientific Research (NWO).
Solid Lubricated Rolling Element Bearings

Science.gov (United States)

1979-02-15

lubricant into uneven patches of varnish . This varnish , along with the file-like action of the exposed ball carbides on the relatively softer races, can...its structure. Fluorine , one of the most reactive elements, reacts with graphite without combustion from about 790’F to 1022°F, forming a grey-colored...to allow for molding and machining after molding. 0 Method 2 (Hughes) Impregnating these dense weaves with a Thermid 600 polyimide varnish
Oleoplaning droplets on lubricated surfaces

Science.gov (United States)

Daniel, Dan; Timonen, Jaakko V. I.; Li, Ruoping; Velling, Seneca J.; Aizenberg, Joanna

2017-10-01

Recently, there has been much interest in using lubricated surfaces to achieve extreme liquid repellency: a foreign droplet immiscible with the underlying lubricant layer was shown to slide off at a small tilt angle behaviour was hypothesized to arise from a thin lubricant overlayer film sandwiched between the droplet and solid substrate, but this has not been observed experimentally. Here, using thin-film interference, we are able to visualize the intercalated film under both static and dynamic conditions. We further demonstrate that for a moving droplet, the film thickness follows the Landau-Levich-Derjaguin law. The droplet is therefore oleoplaning--akin to tyres hydroplaning on a wet road--with minimal dissipative force and no contact line pinning. The techniques and insights presented in this study will inform future work on the fundamentals of wetting for lubricated surfaces and enable their rational design.
Frictional characteristics of stainless steel 440C lubricated with water at pressurized high temperature

International Nuclear Information System (INIS)

Kim, E. H.; Lee, J. S.; Kim, J. H.; Kim, J. I.

2001-01-01

The fatigue life of stainless steel bearings is one of the most critical factors to determine the performance of the driving system. Because the bearings which are installed on the driving mechanism in the nuclear reactor are operated at high temperature and high pressure and especially lubricated with water with low viscosity, the friction and wear characteristics of the bearing material should be investigated thoroughly. In many control element drive mechanisms in the nuclear reactor the support bearings are made of the stainless steel and the sliding bearing ceramic material mainly. This study is focused on the characteristics of support bearing which may be used in the SMART. The ball bearings are made of standardized 440C stainless steel, and it supports thrust load including the weight of the driving system and external force. The friction and wear characteristics of this material operating under severe lubrication condition are not well known yet, however it will be changed with respect to temperature and boundary pressure. In this paper the friction characteristics are investigated experimentally using the reciprocating tribometer which can simulate the SMART operating conditions. Highly purified water is used as lubricant, and the water is warmed up and pressurized. Friction forces on the reciprocating specimens are measured insitu strain gages
Tribological properties of PM212: A high-temperature, self-lubricating, powder metallurgy composite

Science.gov (United States)

Dellacorte, Christopher; Sliney, Harold E.

1989-01-01

This paper describes a research program to develop and evaluate a new high temperature, self-lubricating powder metallurgy composite, PM212. PM212 has the same composition as the plasma-sprayed coating, PS212, which contains 70 wt percent metal-bonded chromium carbide, 15 wt percent silver and 15 wt percent barium fluoride/calcium fluoride eutectic. The carbide acts as a wear resistant matrix and the silver and fluorides act as low and high temperature lubricants, respectively. The material is prepared by sequential cold press, cold isostatic pressing and sintering techniques. In this study, hemispherically tipped wear pins of PM212 were prepared and slid against superalloy disks at temperatures from 25 to 850 C in air in a pin-on-disk tribometer. Friction coefficients range from 0.29 to 0.38 and the wear of both the composite pins and superalloy disks was moderate to low in the 10(exp -5) to 10(exp -6) cubic mm/N-m range. Preliminary tests indicate that the material has a compressive strength of at least 130 MPa over the entire temperature range of 25 to 900 C. This material has promise for use as seal inserts, bushings, small inside diameter parts and other applications where plasma-sprayed coatings are impractical or too costly.
Tribological properties of PM212 - A high temperature, self-lubricating, powder metallurgy composite

Science.gov (United States)

Dellacorte, Christopher; Sliney, Harold E.

1990-01-01

This paper describes a research program to develop and evaluate a new high temperature, self-lubricating powder metallurgy composite, PM212. PM212 has the same composition as the plasma-sprayed coating, PS212, which contains 70 wt percent metal-bonded chromium carbide, 15 wt percent silver and 15 wt percent barium fluoride/calcium fluoride eutectic. The carbide acts as a wear resistant matrix and the silver and fluorides act as low and high temperature lubricants, respectively. The material is prepared by sequential cold press, cold isostatic pressing and sintering techniques. In this study, hemispherically tipped wear pins of PM212 were prepared and slid against superalloy disks at temperatures from 25 to 850 C in air in a pin-on-disk tribometer. Friction coefficients range from 0.29 to 0.38 and the wear of both the composite pins and superalloy disks was moderate to low in the 10(exp -5) to 10(exp -6) cubic mm/N-m range. Preliminary tests indicate that the material has a compressive strength of at least 130 MPa over the entire temperature range of 25 to 900 C. This material has promise for use as seal inserts, bushings, small inside diameter parts and other applications where plasma-sprayed coatings are impractical or too costly.
State-of-the-Art of Extreme Pressure Lubrication Realized with the High Thermal Diffusivity of Liquid Metal.

Science.gov (United States)

Li, Haijiang; Tian, Pengyi; Lu, Hongyu; Jia, Wenpeng; Du, Haodong; Zhang, Xiangjun; Li, Qunyang; Tian, Yu

2017-02-15

Sliding between two objects under very high load generally involves direct solid-solid contact at molecular/atomic level, the mechanism of which is far from clearly disclosed yet. Those microscopic solid-solid contacts could easily lead to local melting of rough surfaces. At extreme conditions, this local melting could propagate to the seizure and welding of the entire interface. Traditionally, the microscopic solid-solid contact is alleviated by various lubricants and additives based on their improved mechanical properties. In this work, we realized the state-of-the-art of extreme pressure lubrication by utilizing the high thermal diffusivity of liquid metal, 2 orders of magnitude higher than general organic lubricants. The extreme pressure lubrication property of gallium based liquid metal (GBLM) was compared with gear oil and poly-α-olefin in a four-ball test. The liquid metal lubricates very well at an extremely high load (10 kN, the maximum capability of a four-ball tester) at a rotation speed of 1800 rpm for a duration of several minutes, much better than traditional organic lubricants which typically break down within seconds at a load of a few kN. Our comparative experiments and analysis showed that this superextreme pressure lubrication capability of GBLM was attributed to the synergetic effect of the ultrafast heat dissipation of GBLM and the low friction coefficient of FeGa 3 tribo-film. The present work demonstrated a novel way of improving lubrication capability by enhancing the lubricant thermal properties, which might lead to mechanical systems with much higher reliability.
Estimation of temperature in the lubricant film during cold forging of stainless steel based on studies of phase transformation in the film

DEFF Research Database (Denmark)

Steenberg, Thomas; Olsen, J.S.; Christensen, Erik

1999-01-01

-3(PO4)(2). 4H(2)O and amorphous Zn1.5Ca1.5(PO4)(2)) lubricated with soap or MoS2. The temperature in the lubricant film during the process was estimated from changes in friction in correlation with observed phase transitions in the lubricant. Phase transitions in the carrier coatings as a function...
Ionic Liquids as Novel Lubricants and /or Lubricant Additives

Energy Technology Data Exchange (ETDEWEB)

Qu, J. [ORNL; Viola, M. B. [General Motors Company

2013-10-31

This ORNL-GM CRADA developed ionic liquids (ILs) as novel lubricants or oil additives for engine lubrication. A new group of oil-miscible ILs have been designed and synthesized with high thermal stability, non-corrosiveness, excellent wettability, and most importantly effective anti-scuffing/anti-wear and friction reduction characteristics. Mechanistic analysis attributes the superior lubricating performance of IL additives to their physical and chemical interactions with metallic surfaces. Working with a leading lubricant formulation company, the team has successfully developed a prototype low-viscosity engine oil using a phosphonium-phosphate IL as an anti-wear additive. Tribological bench tests of the IL-additized formulated oil showed 20-33% lower friction in mixed and elastohydrodynamic lubrication and 38-92% lower wear in boundary lubrication when compared with commercial Mobil 1 and Mobil Clean 5W-30 engine oils. High-temperature, high load (HTHL) full-size engine tests confirmed the excellent anti-wear performance for the IL-additized engine oil. Sequence VID engine dynamometer tests demonstrated an improved fuel economy by >2% for this IL-additized engine oil benchmarked against the Mobil 1 5W-30 oil. In addition, accelerated catalyst aging tests suggest that the IL additive may potentially have less adverse impact on three-way catalysts compared to the conventional ZDDP. Follow-on research is needed for further development and optimization of IL chemistry and oil formulation to fully meet ILSAC GF-5 specifications and further enhance the automotive engine efficiency and durability.
Lubrication a practical guide to lubricant selection

CERN Document Server

Lansdown, A R

1982-01-01

Lubrication: A Practical Guide to Lubricant Selection provides a guide to modern lubrication practice in industry, with emphasis on practical application, selection of lubricants, and significant factors that determine suitability of a lubricant for a specific application. Organized into 13 chapters, this book begins with a brief theoretical opening chapter on the basic principles of lubrication. A chapter then explains the choice of lubricant type, indicating how to decide whether to use oil, grease, dry lubricant, or gas lubrication. Subsequent chapters deal with detailed selection of lubric
Lubricant-impregnated surfaces for electrochemical applications, and devices and systems using same

Energy Technology Data Exchange (ETDEWEB)

Solomon, Brian Richmond; Chen, Xinwei; Chiang, Yet-Ming; Varanasi, Kripa K.

2018-04-17

In certain embodiments, the invention relates to an electrochemical device having a liquid lubricant impregnated surface. At least a portion of the interior surface of the electrochemical device includes a portion that includes a plurality of solid features disposed therein. The plurality of solid features define a plurality of regions therebetween. A lubricant is disposed in the plurality of regions which retain the liquid lubricant in the plurality of regions during operation of the device. An electroactive phase comes in contact with at least the portion of the interior surface. The liquid lubricant impregnated surface introduces a slip at the surface when the electroactive phase flows along the surface. The electroactive phase may be a yield stress fluid.
Tribological Properties of a Pennzane(Registered Trademark)-Based Liquid Lubricant (Disubstituted Alkylated Cyclopentane) for Low Temperature Space Applications

Science.gov (United States)

Venier, Clifford; Casserly, Edward W.; Jones, William R., Jr.; Marchetti, Mario; Jansen, Mark J.; Predmore, Roamer E.

2002-01-01

The tribological properties of a disubstituted alkylated cyclopentane, Pennzane (registered) Synthesized Hydrocarbon Fluid X-1000, are presented. This compound is a lower molecular weight version of the commonly used multiply alkylated cyclopentane, Pennzane X-2000, currently used in many space mechanisms. New, lower temperature applications will require liquid lubricants with lower viscosities and pour points and acceptable vapor pressures. Properties reported include: friction and wear studies and lubricated lifetime in vacuum; additionally, typical physical properties (i.e., viscosity-temperature, pour point, flash and fire point, specific gravity, refractive index, thermal properties, volatility and vapor pressure) are reported.
Evaluation of minimum quantity lubrication grinding with nano-particles and recent related patents.

Science.gov (United States)

Li, Changhe; Wang, Sheng; Zhang, Qiang; Jia, Dongzhou

2013-06-01

In recent years, a large number of patents have been devoted to developing minimum quantity lubrication (MQL) grinding techniques that can significantly improve both environmentally conscious and energy saving and costeffective sustainable grinding fluid alternatives. Among them, one patent is about a supply system for the grinding fluid in nano-particle jet MQL, which produced MQL lubricant by adding solid nano-particles in degradable grinding fluid. The MQL supply device turns the lubricant to the pulse drops with fixed pressure, unchanged pulse frequency and the same drop diameter. The drops will be produced and injected in the grinding zone in the form of jet flow under high pressure gas and air seal. As people become increasingly demanding on our environment, minimum quantity lubrication has been widely used in the grinding and processing. Yet, it presents the defect of insufficient cooling performance, which confines its development. To improve the heat transfer efficiency of MQL, nano-particles of a certain mass fraction can be added in the minimum quantity of lubricant oil, which concomitantly will improve the lubrication effects in the processing. In this study, the grinding experiment corroborated the effect of nano-particles in surface grinding. In addition, compared with other forms of lubrication, the results presented that the grinding force, the friction coefficient and specific grinding energy of MQL grinding have been significantly weakened, while G ratio greatly rose. These are attributed to the friction oil-film with excellent anti-friction and anti-wear performance, which is generated nano-particles at the wheel/workpiece interface. In this research, the cooling performance of nano-particle jet MQL was analyzed. Based on tests and experiments, the surface temperature was assayed from different methods, including flood lubricating oil, dry grinding, MQL grinding and nano-particle jet MQL grinding. Because of the outstanding heat transfer
Investigation of laser cladding high temperature anti-wear composite coatings on Ti6Al4V alloy with the addition of self-lubricant CaF2

International Nuclear Information System (INIS)

Xiang, Zhan-Feng; Liu, Xiu-Bo; Ren, Jia; Luo, Jian; Shi, Shi-Hong; Chen, Yao; Shi, Gao-Lian; Wu, Shao-Hua

2014-01-01

Highlights: • A novel high temperature self-lubricating wear-resistant coating was fabricated. • TiC carbides and self-lubricant CaF 2 were “in situ” synthesized in the coating. • The coating with the addition of CaF 2 possessed superior properties than without. - Abstract: To improve the high-temperature tribological properties of Ti–6Al–4V alloy, γ-NiCrAlTi/TiC and γ-NiCrAlTi/TiC/CaF 2 coatings were fabricated on Ti–6Al–4V alloy by laser cladding. The phase compositions and microstructure of the coatings were investigated using X-ray diffraction (XRD) and scanning electron microscope (SEM) equipped with energy dispersive spectroscopy (EDS). The tribological behaviors were evaluated using a ball-on-disk tribometer from ambient temperature to 600 °C under dry sliding wear conditions and the corresponding wear mechanisms were discussed. The results indicated that the γ-NiCrAlTi/TiC/CaF 2 coating consisted of α-Ti, the “in situ” synthesized TiC block particles and dendrite, γ-NiCrAlTi solid solution and spherical CaF 2 particles. The wear rates of γ-NiCrAlTi/TiC/CaF 2 coating were decreased greatly owing to the combined effects of the reinforced carbides and continuous lubricating films. Furthermore, the friction coefficients of γ-NiCrAlTi/TiC/CaF 2 coating presented minimum value of 0.21 at 600 °C, which was reduced by 43% and 50% compared to the substrate and γ-NiCrAlTi/TiC coating respectively. It was considered that the γ-NiCrAlTi/TiC/CaF 2 coating exhibited excellent friction-reducing and anti-wear properties at high temperature
A Review of Ionic Liquid Lubricants

OpenAIRE

Anthony E. Somers; Patrick C. Howlett; Douglas R. MacFarlane; Maria Forsyth

2013-01-01

Due to ever increasing demands on lubricants, such as increased service intervals, reduced volumes and reduced emissions, there is a need to develop new lubricants and improved wear additives. Ionic liquids (ILs) are room temperature molten salts that have recently been shown to offer many advantages in this area. The application of ILs as lubricants in a diverse range of systems has found that these materials can show remarkable protection against wear and significantly reduce friction in th...
Lubrication for hot working of titanium alloys

International Nuclear Information System (INIS)

Gotlib, B.M.

1980-01-01

The isothermal lubrication of the following composition is suggested, wt. %: aluminium powder 4-6, iron scale 15-25, vitreous enamel up to 100. The lubricant improves forming and decreases the danger of the metal fracture when titanium alloys working. It is advisable to use the suggested lubrication when stamping thin-walled products of titanium alloys at the blank temperature from 700 to 1000 deg C [ru
Improved Ionic Liquids as Space Lubricants, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Ionic liquids are candidate lubricant materials. However for application in low temperature space mechanisms their lubrication performance needs to be enhanced. UES...

Investigation of laser cladding high temperature anti-wear composite coatings on Ti6Al4V alloy with the addition of self-lubricant CaF{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Xiang, Zhan-Feng [School of Mechanical and Electric Engineering, Soochow University, 178 East Ganjiang Road, Suzhou 215006 (China); Liu, Xiu-Bo, E-mail: liuxiubo@suda.edu.cn [School of Mechanical and Electric Engineering, Soochow University, 178 East Ganjiang Road, Suzhou 215006 (China); Ren, Jia; Luo, Jian; Shi, Shi-Hong; Chen, Yao [School of Mechanical and Electric Engineering, Soochow University, 178 East Ganjiang Road, Suzhou 215006 (China); Shi, Gao-Lian; Wu, Shao-Hua [Suzhou Institute of Industrial Technology, Suzhou 215104 (China)

2014-09-15

Highlights: • A novel high temperature self-lubricating wear-resistant coating was fabricated. • TiC carbides and self-lubricant CaF{sub 2} were “in situ” synthesized in the coating. • The coating with the addition of CaF{sub 2} possessed superior properties than without. - Abstract: To improve the high-temperature tribological properties of Ti–6Al–4V alloy, γ-NiCrAlTi/TiC and γ-NiCrAlTi/TiC/CaF{sub 2} coatings were fabricated on Ti–6Al–4V alloy by laser cladding. The phase compositions and microstructure of the coatings were investigated using X-ray diffraction (XRD) and scanning electron microscope (SEM) equipped with energy dispersive spectroscopy (EDS). The tribological behaviors were evaluated using a ball-on-disk tribometer from ambient temperature to 600 °C under dry sliding wear conditions and the corresponding wear mechanisms were discussed. The results indicated that the γ-NiCrAlTi/TiC/CaF{sub 2} coating consisted of α-Ti, the “in situ” synthesized TiC block particles and dendrite, γ-NiCrAlTi solid solution and spherical CaF{sub 2} particles. The wear rates of γ-NiCrAlTi/TiC/CaF{sub 2} coating were decreased greatly owing to the combined effects of the reinforced carbides and continuous lubricating films. Furthermore, the friction coefficients of γ-NiCrAlTi/TiC/CaF{sub 2} coating presented minimum value of 0.21 at 600 °C, which was reduced by 43% and 50% compared to the substrate and γ-NiCrAlTi/TiC coating respectively. It was considered that the γ-NiCrAlTi/TiC/CaF{sub 2} coating exhibited excellent friction-reducing and anti-wear properties at high temperature.
3D Imaging of Water-Drop Condensation on Hydrophobic and Hydrophilic Lubricant-Impregnated Surfaces

Science.gov (United States)

Kajiya, Tadashi; Schellenberger, Frank; Papadopoulos, Periklis; Vollmer, Doris; Butt, Hans-Jürgen

2016-04-01

Condensation of water from the atmosphere on a solid surface is an ubiquitous phenomenon in nature and has diverse technological applications, e.g. in heat and mass transfer. We investigated the condensation kinetics of water drops on a lubricant-impregnated surface, i.e., a micropillar array impregnated with a non-volatile ionic liquid. Growing and coalescing drops were imaged in 3D using a laser scanning confocal microscope equipped with a temperature and humidity control. Different stages of condensation can be discriminated. On a lubricant-impregnated hydrophobic micropillar array these are: (1) Nucleation on the lubricant surface. (2) Regular alignment of water drops between micropillars and formation of a three-phase contact line on a bottom of the substrate. (3) Deformation and bridging by coalescence which eventually leads to a detachment of the drops from the bottom substrate. The drop-substrate contact does not result in breakdown of the slippery behaviour. Contrary, on a lubricant-impregnated hydrophilic micropillar array, the condensed water drops replace the lubricant. Consequently, the surface loses its slippery property. Our results demonstrate that a Wenzel-like to Cassie transition, required to maintain the facile removal of condensed water drops, can be induced by well-chosen surface hydrophobicity.
Thermochemical recycling of mixture of scrap tyres and waste lubricating oil into high caloric value products

International Nuclear Information System (INIS)

Abdul-Raouf, Manar E.; Maysour, Nermine E.; Abdul-Azim, Abdul-Azim A.; Amin, Mahasen S.

2010-01-01

Scrap tyres and used lubricating oils represent together growing environmental problem because they are not biodegradable and their components cannot readily be recovered. In the present investigation, the thermochemical recycling of mixture of old tyres with waste lubricating oil by pyrolysis and the value of the products obtained have been studied. First, thermobalance experiments were carried out, studying the influence of the following variables: temperature, type of catalyst and catalyst concentration on the pyrolysis reaction of a mixture of 1/1 wt./wt. oil/tyre ratio. These thermobalance results were thoroughly investigated to study the effect of the main process variables on yields of derived products: oils, gases and solid residue.
Numerical simulation of lubrication mechanisms at mesoscopic scale

DEFF Research Database (Denmark)

Hubert, C.; Bay, Niels; Christiansen, Peter

2011-01-01

The mechanisms of liquid lubrication in metal forming are studied at a mesoscopic scale, adopting a 2D sequential fluid-solid weak coupling approach earlier developed in the first author's laboratory. This approach involves two computation steps. The first one is a fully coupled fluid-structure F...... of pyramidal indentations. The tests are performed with variable reduction and drawing speed under controlled front and back tension forces. Visual observations through a transparent die of the fluid entrapment and escape from the cavities using a CCD camera show the mechanisms of Micro......PlastoHydroDynamic Lubrication (MPHDL) as well as cavity shrinkage due to lubricant compression and escape and strip deformation....
Ionic liquids as lubricant additives: A review

International Nuclear Information System (INIS)

Zhou, Yan; Qu, Jun

2016-01-01

In pursuit of energy efficiency and durability throughout human history, advances in lubricants have always played important roles. Ionic liquids (ILs) are room-temperature molten salts that possess unique physicochemical properties and have shown great potential in many applications with lubrication as one of the latest. While earlier work (2001–2011) primarily explored the feasibility of using ILs as neat or base lubricants, using ILs as lubricant additives has become the new focal research topic since the breakthrough in ILs’ miscibility in nonpolar hydrocarbon oils in early 2012. This work reviews the recent advances in developing ILs as additives for lubrication with an attempt to correlate among the cationic and anionic structures, oil-solubility, and other relevant physicochemical properties, and lubricating behavior. Effects of the concentration of ILs in lubricants and the compatibility between ILs and other additives in the lubricant formulation on the tribological performance are described followed by a discussion of wear protection mechanism based on tribofilm characterization. As a result, future research directions are suggested at the end.
Lubrication fundamentals

International Nuclear Information System (INIS)

Wills, J.G.

1990-01-01

This book is organized under the following headings: lubricating oils; lubricating greases; synthetic lubricants; machine elements; lubricant application; internal combustion engines; stationary gas turbines; steam turbines; hydraulic turbines; nuclear power plants; automotive chassis components; automotive power transmissions; compressors; handling, storing, and dispensing lubricants, in-plant handling for lubricant conservation
Lubrication fundamentals

CERN Document Server

Pirro, DM

2001-01-01

This work discusses product basics, machine elements that require lubrication, methods of application, lubricant storage and handling, and lubricant conservation. This edition emphasizes the need for lubrication and careful lubricant selection.
Direct verification of the lubrication force on a sphere travelling through a viscous film upon approach to a solid wall

KAUST Repository

Marston, Jeremy

2010-05-21

Experiments were performed to observe the motion of a solid sphere approaching a solid wall through a thin layer of a viscous liquid. We focus mainly on cases where the ratio of the film thickness, ℘, to the sphere diameter, D, is in the range 0.03 ℘lubrication theory. Using high-speed video imaging we show, for the first time, that the equations of motion based on the lubrication approximation correctly describe the deceleration of the sphere when St < Stc. Furthermore, we show that the penetration depth at which the sphere motion is first arrested by the viscous force, which decreases with increasing Stokes number, matches well with theoretical predictions. An example for a shear-thinning liquid is also presented, showing that this simple set-up may be used to deduce the short-time dynamical behaviour of non-Newtonian liquids. © 2010 Cambridge University Press.
Improvement of Drill Performance in Metal Cutting Using MoST Solid Lubricant Coatings

Institute of Scientific and Technical Information of China (English)

N.R. Thomas; D.G. Teer; S. Yang; S. Hickman

2004-01-01

Coated tools are widely used in today's metal cutting industries and have significantly improved machining productivity through reducing operation costs and time. This paper presents the results of a systematic study of the performance of HSS drills coated with CrTiAlN and drills with a top solid lubricant coating of MoSTTM. The tests were performed on a Haas vertical machining centre under wet and dry cutting conditions to machine through holes in medium carbon steel workpieces. The feed force and torque were recorded throughout some of the tests using a force dynamometer,while the tool wear was monitored and measured. It was found that MoSTTM coatings even under accelerated conditions improve the tool life significantly based on their unique properties and very low friction.
Influence of the Previous Preheating Temperature on the Static Coefficient of Friction with Lubrication

Directory of Open Access Journals (Sweden)

M. Živković

2016-12-01

Full Text Available Experimental investigations static coefficient of friction in lubricated conditions and pre-heating of the sample pin at high temperatures is discussed in this paper. The static coefficient of friction was measured in the sliding steel copper pins per cylinder of polyvinylchloride. Pins are previously heated in a special chamber from room temperature to a temperature of 800 oC with a step of 50 °C. Tribological changes in the surface layer of the pins caused by pre-heating the pins at high temperatures and cooling systems have very significantly influenced the increase in the coefficient of static friction. The results indicate the possibility of improving the friction characteristics of metal materials based on their thermal treatment at elevated temperatures.
Biofluid lubrication for artificial joints

Science.gov (United States)

Pendleton, Alice Mae

This research investigated biofluid lubrication related to artificial joints using tribological and rheological approaches. Biofluids studied here represent two categories of fluids, base fluids and nanostructured biofluids. Base fluids were studied through comparison of synthetic fluids (simulated body fluid and hyaluronic acid) as well as natural biofluids (from dogs, horses, and humans) in terms of viscosity and fluid shear stress. The nano-structured biofluids were formed using molecules having well-defined shapes. Understanding nano-structured biofluids leads to new ways of design and synthesis of biofluids that are beneficial for artificial joint performance. Experimental approaches were utilized in the present research. This includes basic analysis of biofluids' property, such as viscosity, fluid shear stress, and shear rate using rheological experiments. Tribological investigation and surface characterization were conducted in order to understand effects of molecular and nanostructures on fluid lubrication. Workpiece surface structure and wear mechanisms were investigated using a scanning electron microscope and a transmission electron microscope. The surface topography was examined using a profilometer. The results demonstrated that with the adding of solid additives, such as crown ether or fullerene acted as rough as the other solids in the 3-body wear systems. In addition, the fullerene supplied low friction and low wear, which designates the lubrication purpose of this particular particle system. This dissertation is constructed of six chapters. The first chapter is an introduction to body fluids, as mentioned earlier. After Chapter II, it examines the motivation and approach of the present research, Chapter III discusses the experimental approaches, including materials, experimental setup, and conditions. In Chapter IV, lubrication properties of various fluids are discussed. The tribological properties and performance nanostructured biofluids are
Thermochemical recycling of mixture of scrap tyres and waste lubricating oil into high caloric value products

Energy Technology Data Exchange (ETDEWEB)

Abdul-Raouf, Manar E.; Maysour, Nermine E.; Abdul-Azim, Abdul-Azim A. [Egyptian Petroleum Research Institute, Nasr City, Cairo (Egypt); Amin, Mahasen S. [Faculty of Science, Benha University, Benha (Egypt)

2010-06-15

Scrap tyres and used lubricating oils represent together growing environmental problem because they are not biodegradable and their components cannot readily be recovered. In the present investigation, the thermochemical recycling of mixture of old tyres with waste lubricating oil by pyrolysis and the value of the products obtained have been studied. First, thermobalance experiments were carried out, studying the influence of the following variables: temperature, type of catalyst and catalyst concentration on the pyrolysis reaction of a mixture of 1/1 wt./wt. oil/tyre ratio. These thermobalance results were thoroughly investigated to study the effect of the main process variables on yields of derived products: oils, gases and solid residue. (author)
Experimental evaluation of chromium-carbide-based solid lubricant coatings for use to 760 C

Science.gov (United States)

Dellacorte, Christopher

1987-01-01

A research program is described which further developed and investigated chromium carbide based self-lubricating coatings for use to 760 C. A bonded chromium carbide was used as the base stock because of the known excellent wear resistance and the chemical stability of chromium carbide. Additives were silver and barium fluoride/calcium fluoride eutectic. The three coating components were blended in powder form, applied to stainless steel substrates by plasma spraying and then diamond ground to the desired coating thickness. A variety of coating compositions was tested to determine the coating composition which gave optimum tribological results. Coatings were tested in air, helium, and hydrogen at temperatures from 25 to 760 C. Several counterface materials were evaluated with the objective of discovering a satisfactory metal/coating sliding combination for potential applications, such as piston ring/cylinder liner couples for Stirling engines. In general, silver and fluoride additions to chromium carbide reduced the friction coefficient and increased the wear resistance relative to the unmodified coating. The lubricant additives acted synergistically in reducing friction and wear.
Genesis and stability of tribolayers in solid lubrication: case of pair DLC-stainless steel

Directory of Open Access Journals (Sweden)

Diego Berti Salvaro

2016-04-01

Full Text Available The morphology, dimensions and chemical composition of tribolayers strongly depend on the pressures and temperatures acting on the contact. They are formed by reactions between surfaces in contact with each other as well as with the atmosphere, lubricants and possible contaminants. In this paper, the influence of test time (180, 500, 1000 and 2500 h on the formation and characteristics of tribolayers in pairs of DLC-stainless steel that were tested under an atmosphere of refrigerant gas R134a and without lubricating oil was analyzed. The characterization was performed using scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS (morphology and chemical composition and white light interferometry (thickness. The tribolayer thicknesses ranged from 100 to 500 nm, and they were composed of elements originating from mutual transfers between the tribological pairs, as well as oxides that were more pronounced on the stainless steel surface. The results show that the tribolayers are chemically stable, maintaining the same composition over time, and their thicknesses remained constant after 1000 h of testing.
Tribology of the lubricant quantized sliding state.

Science.gov (United States)

Castelli, Ivano Eligio; Capozza, Rosario; Vanossi, Andrea; Santoro, Giuseppe E; Manini, Nicola; Tosatti, Erio

2009-11-07

In the framework of Langevin dynamics, we demonstrate clear evidence of the peculiar quantized sliding state, previously found in a simple one-dimensional boundary lubricated model [A. Vanossi et al., Phys. Rev. Lett. 97, 056101 (2006)], for a substantially less idealized two-dimensional description of a confined multilayer solid lubricant under shear. This dynamical state, marked by a nontrivial "quantized" ratio of the averaged lubricant center-of-mass velocity to the externally imposed sliding speed, is recovered, and shown to be robust against the effects of thermal fluctuations, quenched disorder in the confining substrates, and over a wide range of loading forces. The lubricant softness, setting the width of the propagating solitonic structures, is found to play a major role in promoting in-registry commensurate regions beneficial to this quantized sliding. By evaluating the force instantaneously exerted on the top plate, we find that this quantized sliding represents a dynamical "pinned" state, characterized by significantly low values of the kinetic friction. While the quantized sliding occurs due to solitons being driven gently, the transition to ordinary unpinned sliding regimes can involve lubricant melting due to large shear-induced Joule heating, for example at large speed.
Advanced `KS-6` dry type lubricant for aluminum sheet forming; Arumi ban seikeiyo koseino kokei junkatsuzai `KS-5`

Energy Technology Data Exchange (ETDEWEB)

Matsui, K.; Sugita, T.; Imamura, Y. [Kobe Steel, Ltd., Kobe (Japan)

1997-09-01

The advanced `KS-5` dry film type lubricant was developed for press forming of aluminum sheets. KS-5 uses water- soluble resin poly-alkylene-oxide superior in formability, weldability and adhesivity, and contains higher fatty-acid soap as oil solvent to improve a formability. The verification test result of KS-5 is as follows. Both stretchability and drawability were confirmed through a ball head stretching test and a cylinder drawing test as formability test, respectively, and a forming height more than that of mild steel sheets was obtained by using the solid lubricant showing a high stretchability. The drawability of nearly 80% of that of mild steel sheets was also obtained showing a high formability. Since the amount of the solid lubricant has reciprocal effect on the formability and degreasing property, it is important to select the suitable amount of the solid lubricant according to use conditions. Lubricants generally deteriorate a spot weldability, however, this lubricant has no practical problems by coating rust preventive oil. 3 refs., 8 figs., 3 tabs.
Development of new engine bearings with overlay consisting of solid lubricants; Kotai junkatsu overlay tsuki engine yo suberi jikuuke zairyo no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Kanayama, H; Kawakami, S; Gohara, C [Taiho Kogyo Co. Ltd., Aichi (Japan); Fuwa, Y; Michioka, H [Toyota Motor Corp., Aichi (Japan)

1997-10-01

Recently, modern engines have a tendency for higher output and longer periods. As a result , higher bearing performance is required. For this reason, we have developed the new conceptual overlay consisting of solid lubricants and thermosetting plastics. This paper describes the performance of engine bearings with the new overlay. 5 refs., 13 figs., 5 tabs.
Advanced lubrication systems and materials. Final report

Energy Technology Data Exchange (ETDEWEB)

Hsu, S.

1998-05-07

This report described the work conducted at the National Institute of Standards and Technology under an interagency agreement signed in September 1992 between DOE and NIST for 5 years. The interagency agreement envisions continual funding from DOE to support the development of fuel efficient, low emission engine technologies in terms of lubrication, friction, and wear control encountered in the development of advanced transportation technologies. However, in 1994, the DOE office of transportation technologies was reorganized and the tribology program was dissolved. The work at NIST therefore continued at a low level without further funding from DOE. The work continued to support transportation technologies in the development of fuel efficient, low emission engine development. Under this program, significant progress has been made in advancing the state of the art of lubrication technology for advanced engine research and development. Some of the highlights are: (1) developed an advanced high temperature liquid lubricant capable of sustaining high temperatures in a prototype heat engine; (2) developed a novel liquid lubricant which potentially could lower the emission of heavy duty diesel engines; (3) developed lubricant chemistries for ceramics used in the heat engines; (4) developed application maps for ceramic lubricant chemistry combinations for design purpose; and (5) developed novel test methods to screen lubricant chemistries for automotive air-conditioning compressors lubricated by R-134a (Freon substitute). Most of these findings have been reported to the DOE program office through Argonne National Laboratory who manages the overall program. A list of those reports and a copy of the report submitted to the Argonne National Laboratory is attached in Appendix A. Additional reports have also been submitted separately to DOE program managers. These are attached in Appendix B.
Evaluation report on the development of ultra-solid lubricant with cluster diamond; Cluster diamond wo riyoshita kotai junkatsu fukugo zairyo no kaihatsu hyoka hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

The fiscal 1998-2000 results of efforts to develop cluster diamond (CD)-diffused solid lubricant composite materials expected to exhibit excellent lubrication are stated. Since friction greatly affects machine life and energy efficiency, friction reduction is an important task. Very hard and microscopic CD was utilized for the achievement of a friction coefficient of 0.08. A manufacturing technology for molds 10nm or smaller was developed, which enabled the development of a gear not larger than 8mm. The success will enable the operation of micromachines in the absence of lubrication which is impossible at present. A CD-aided functional layer creation technology was also developed. It is expected that the development and practical application of micromechanisms will make rapid progress in the 21st century. Much is expected from the creation, and goods with the achievement applied thereto, of advanced technologies whereinto non-lubrication, functional layer creation, and excellent heat conductivity are incorporated. It is quite significant that, since CD is available in any field as far as light-load low-speed sliding conditions are satisfied, sliding parts will be improved and service life will be prolonged. (NEDO)
Development of high performance lubricant through the compatibility of polyalphaolefin, polyurea and irradiated polytetrafluoroethylene; Graxa de poliureia: estudo da compatibilidade da poliureia, polialfaolefina e politetrafluoretileno irradiado para melhoria da lubricidade e estabilidade

Energy Technology Data Exchange (ETDEWEB)

Ratao, Natalia Torres

2013-07-01

Lubricants are gaseous, liquid, semi solid or solid (powder) materials those form a film between two parties preventing friction. High performance lubricants are designed to work under severe conditions of temperature, pressure, and contamination. The most used are liquids (oils) and semi solids (greases). Greases are applied where oils can drain or in inaccessible places and are divided generally into two classes, soap and no soap. The most used non soap grease is polyurea, obtained by the reaction between amine and isocyanate, has highly thixotropic, high dielectric strength and excellent anticorrosive property, so it is widely used for lubrication of electric motors and shipbuilding machinery. For a grease with high performance, in this study was used a synthetic lubricant fluid, polyalphaolefin, and was also employed solid lubricant additive polytetrafluoroethylene (PTFE) due its lowest coefficient of friction, is found commercially irradiated in air to obtain smaller particles and to produce oxygenated terminal groups those are more compatible with the metal surface. The tests conducted were comparatively between pure polyurea grease and with PTFE additive. The characterizations were made by infrared spectroscopy and elemental analysis of C, N and H and Free NCO index, proving the formation of four carbons polyurea (tetraurea). The functional analysis of drop point and oil separation showed high stability and compatibility between the polymers increased when PTFE was added. The excellent resistance of pure tetraurea grease to wear and extreme pressure were demonstrated by four-ball and practical bearings tests, characterizing this grease as a high performance lubricant, when compared to most used greases in the market. (author)

Oils; lubricants; paraffin-wax compositions; hydrocarbon condensation products

Energy Technology Data Exchange (ETDEWEB)

1934-04-04

Petroleum hydrocarbons such as gasoline, kerosene, Diesel fuel oil, lubricating-oil, and paraffin wax, and like hydrocarbons such as are obtainable from shale oil and by the hydrogenation of carbonaceous materials, are improved by addition of products obtained by condensing a cyclic hydrocarbon with a saturated dihalogen derivative of an aliphatic hydrocarbon containing less than five carbon atoms. The addition of the condensation products increases the viscosity of the hydrocarbon oils specified, and is particularly useful in the case of lubricating-oils; addition of the condensation products to paraffin wax increases the transparency and adherent properties of the wax, and is useful in the manufacture of moulded articles such as candles; the products may also be used in solid lubricating-compositions.
Formulation of lubricating grease using Beeswax thickener

Science.gov (United States)

Suhaila, N.; Japar, A.; Aizudin, M.; Aziz, A.; Najib Razali, Mohd

2018-04-01

The issues on environmental pollution has brought the industries to seek the alternative green solutions for lubricating grease formulation. The significant challenges in producing modified grease are in which considering the chosen thickener as one of the environmental friendly material. The main purposes of the current research were to formulate lubricant grease using different types of base oils and to study the effect of thickener on the formulated lubricant grease. Used oil and motor oil were used as the base oils for the grease preparation. Beeswax and Damar were used as thickener and additive. The grease is tested based on its consistency, stability and oil bleeding. The prepared greases achieved grease consistency of grade 2 and 3 except for grease with unfiltered used oil. Grease formulated with used oil and synthetic oil tend to harden and loss its lubricating ability under high temperature compared to motor oil’ grease. Grease modification using environmental friendly thickener were successfully formulated but it is considered as a low temperature grease as the beeswax have low melting point of 62°C-65°C.
Development and evaluation of a high performance lubricant for industrial gears; Desenvolvimento e avaliacao de lubrificantes de alto desempenho para engrenagens industriais

Energy Technology Data Exchange (ETDEWEB)

Araujo, Laura Denise Santiago de; Silva, Ademir Oliveira da [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil); Oliveira, Adelci Menezes de [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

2008-07-01

Nowadays, new machines are submitted to higher efforts with smaller clearances. For them it is necessary to develop high performance lubricants in order to reduce friction, wear and emissions for internal combustion engines. In this work it was developed two lubricants, prepared with MoS{sub 2} (Molybdenum Disulfide) and LIC (Lubricant Intermetallic Compound), and they were compared to commercial oil, at the same viscosity grade ISO VG 320. The oils were tested in a four ball tribometer, at 1200 rpm, at initial temperature of 40 deg C and at 80 kgf. The friction reduction was of 13 % and 18 % for MoS{sub 2} and LIC oil, respectively. The wear was the same for all tested oils. Besides tests in the four ball machine, all oils were characterized by viscosity, demulsibility and atomic emission spectroscopy. The lubricants formulated with solids particles were considered as high performance. (author)
Top-of-Rail lubricant

Energy Technology Data Exchange (ETDEWEB)

Alzoubi, M. F.; Fenske, G. R.; Erck, R. A.; Boparai, A. S.

2000-07-14

Analysis of the volatile and semivolatile fractions collected after use of the TOR lubricant indicated that other than contaminants in the collection laboratory, no compounds on the EPA's Target Compound Lists (Tables 2 and 5) were detected in these fractions. The data of these qualitative analyses, given in the various tables in the text, indicate only the relative amounts of the tentatively identified compounds. The authors recommend that quantitative analysis be performed on the volatile and semivolatile fractions to allow confirmation of the tentatively identified compounds and to obtain absolute amounts of the detected compounds. Additionally, the semivolatile fraction should be analyzed by liquid chromatography/mass spectrometry to identify compounds that are not chromatographable under the temperature program used for determination of semivolatile compounds. Introducing the top-of-rail (TOR) lubricant into the wheel/rail interface results in a reduction of almost 60% of lateral friction force over the forces encountered under dry conditions. This reveals good potential for energy savings, as well as wear reduction, for railroad companies. In TOR lubrication, an increase in the angle of attack and axle load results in increased lateral friction and rate of lubricant consumption. The most efficient TOR lubricant quantity to be used in the wheel/rail interface must be calculated precisely according to the number of cars, axle loads, train speed, and angle of attack.
Tribological study for the application of biodegradable lubricants in the industry

Energy Technology Data Exchange (ETDEWEB)

Igartua, A.; Aranzabe, A.; Barriga, J.; Rodriguez, J. [TEKNIKER, Eibar (Spain)

1998-11-01

The main problems in critical machinery elements using vegetable base oil, are the poor behaviour concerning low temperature properties, hydrolytic and oxidation stability problems, overheating, compatibility, smell and corrosivity. Our technical approach deals with the development of new base-stocks such regrew industrial crops, biological and chemically improved vegetable oils decreasing the content of non stable products. It is necessary improve the rheologic behaviour, its oxidation and hydrolytic stability and decrease the actual limit of temperature of machines avoiding nucleation of paraffin`s. Transformation of these high performance oils into higher added value to lubricate gears is another objective of this research. Specialist in the world of surface treatments and lubrication with combined expertise in tribological behaviour and lubrication will perform tests in order to improve technical performance and efficiency of these new vegetable lubricants. Lifecycle cost will help to evaluate environmental and cost effective complete chain. In this paper, characteristics of the reference lubricants actually used for lubricate hydraulic equipment`s are reported. (author) 7 refs.
Light-scattering study of the glass transition in lubricants

Science.gov (United States)

Alsaad, M. A.; Winer, W. O.; Medina, F. D.; Oshea, D. C.

1977-01-01

The sound velocity of four lubricants has been measured as a function of temperature and pressure using Brillouin scattering. A change in slope of the velocity as a function of temperature or pressure allowed the determination of the glass transition temperature and pressure. The glass transition data were used to construct a phase diagram for each lubricant. The data indicate that the glass transition temperature increased with pressure at a rate which ranged from 120 to 200 C/GPa. The maximum pressure attained was 0.69 GPa and the temperature range was from 25 to 100 C.
A friction model for cold forging of aluminum, steel and stainless steel provided with conversion coating and solid film lubricant

DEFF Research Database (Denmark)

Bay, Niels; Eriksen, Morten; Tan, Xincai

2011-01-01

Adopting a simulative tribology test system for cold forging the friction stress for aluminum, steel and stainless steel provided with typical lubricants for cold forging has been determined for varying normal pressure, surface expansion, sliding length and tool/work piece interface temperature...
Comparison Between Oil-mist and Oil-jet Lubrication of High-speed, Small-bore, Angular-contact Ball Bearings

Science.gov (United States)

Pinel, Stanley I.; Signer, Hans R.; Zaretsky, Erwin V.

2001-01-01

Parametric tests were conducted with an optimized 35-mm-bore-angular-contact ball bearing on a high-speed, high-temperature bearing tester. Results from both air-oil mist lubrication and oil-jet lubrication systems used to lubricate the bearing were compared to speeds of 2.5 x 10(exp 6) DN. The maximum obtainable speed with air-oil mist lubrication is 2.5 x 10(exp 6) DN. Lower bearing temperatures and higher power losses are obtained with oil-jet lubrication than with air-oil mist lubrication. Bearing power loss is a direct function of oil flow to the bearing and independent of oil delivery system. For a given oil-flow rate, bearing temperature and power loss increase with increases in speed. Bearing life is an inverse function of temperature, the difference in temperature between the individual bearing ring components, and the resultant elastohydrodynamic (EHD) film thicknesses. Bearing life is independent of the oil delivery system except as it affects temperature. Cage slip increased with increases in speed. Cage slip as high as 7 percent was measured and was generally higher with air-oil mist lubrication than with oil-jet lubrication.
Kinetics approach to modeling of polymer additive degradation in lubricants

Institute of Scientific and Technical Information of China (English)

llyaI.KUDISH; RubenG.AIRAPETYAN; Michael; J.; COVITCH

2001-01-01

A kinetics problem for a degrading polymer additive dissolved in a base stock is studied.The polymer degradation may be caused by the combination of such lubricant flow parameters aspressure, elongational strain rate, and temperature as well as lubricant viscosity and the polymercharacteristics (dissociation energy, bead radius, bond length, etc.). A fundamental approach tothe problem of modeling mechanically induced polymer degradation is proposed. The polymerdegradation is modeled on the basis of a kinetic equation for the density of the statistical distribu-tion of polymer molecules as a function of their molecular weight. The integrodifferential kineticequation for polymer degradation is solved numerically. The effects of pressure, elongational strainrate, temperature, and lubricant viscosity on the process of lubricant degradation are considered.The increase of pressure promotes fast degradation while the increase of temperature delaysdegradation. A comparison of a numerically calculated molecular weight distribution with an ex-perimental one obtained in bench tests showed that they are in excellent agreement with eachother.
On-line surveillance of lubricants in bearings by means of surface acoustic waves.

Science.gov (United States)

Lindner, Gerhard; Schmitt, Martin; Schubert, Josephine; Krempel, Sandro; Faustmann, Hendrik

2010-01-01

The acoustic wave propagation in bearings filled with lubricants and driven by pulsed excitation of surface acoustic waves has been investigated with respect to the presence and the distribution of different lubricants. Experimental setups, which are based on the mode conversion between surface acoustic waves and compression waves at the interface between a solid substrate of the bearing and a lubricant are described. The results of preliminary measurements at linear friction bearings, rotation ball bearings and axial cylinder roller bearings are presented.
Molecular dynamics study of lubricant depletion by pulsed laser heating

Science.gov (United States)

Seo, Young Woo; Rosenkranz, Andreas; Talke, Frank E.

2018-05-01

In this study, molecular dynamics simulations were performed to numerically investigate the effect of pulsed laser heating on lubricant depletion. The maximum temperature, the lubricant depletion width, the number of evaporated lubricant beads and the number of fragmented lubricant chains were studied as a function of laser peak power, pulse duration and repetition rate. A continuous-wave laser and a square pulse laser were simulated and compared to a Gaussian pulse laser. With increasing repetition rate, pulsed laser heating was found to approach continuous-wave laser heating.
Use of Textured Surfaces to Mitigate Sliding Friction and Wear of Lubricated and Non-Lubricated Contacts

Energy Technology Data Exchange (ETDEWEB)

Blau, Peter Julian [ORNL

2012-03-01

If properly employed, the placement of three-dimensional feature patterns, also referred to as textures, on relatively-moving, load-bearing surfaces can be beneficial to their friction and wear characteristics. For example, geometric patterns can function as lubricant supply channels or depressions in which to trap debris. They can also alter lubricant flow in a manner that produces thicker load-bearing films locally. Considering the area occupied by solid areas and spaces, textures also change the load distribution on surfaces. At least ten different attributes of textures can be specified, and their combinations offer wide latitude in surface engineering. By employing directional machining and grinding procedures, texturing has been used on bearings and seals for well over a half century, and the size scales of texturing vary widely. This report summarizes past work on the texturing of load-bearing surfaces, including past research on laser surface dimpling of ceramics done at ORNL. Textured surfaces generally show most pronounced effects when they are used in conformal or nearly conformal contacts, like that in face seals. Combining textures with other forms of surface modification and lubrication methods can offer additional benefits in surface engineering for tribology. As the literature and past work at ORNL shows, texturing does not always provide benefits. Rather, the selected pattern and arrangement of features must be matched to characteristics of the proposed application, bearing materials, and lubricants.
Gear Mesh Loss-of-Lubrication Experiments and Analytical Simulation

Science.gov (United States)

Handschuh, Robert F.; Polly, Joseph; Morales, Wilfredo

2011-01-01

An experimental program to determine the loss-of-lubrication (LOL) characteristics of spur gears in an aerospace simulation test facility has been completed. Tests were conducted using two different emergency lubricant types: (1) an oil mist system (two different misted lubricants) and (2) a grease injection system (two different grease types). Tests were conducted using a NASA Glenn test facility normally used for conducting contact fatigue. Tests were run at rotational speeds up to 10000 rpm using two different gear designs and two different gear materials. For the tests conducted using an air-oil misting system, a minimum lubricant injection rate was determined to permit the gear mesh to operate without failure for at least 1 hr. The tests allowed an elevated steady state temperature to be established. A basic 2-D heat transfer simulation has been developed to investigate temperatures of a simulated gear as a function of frictional behavior. The friction (heat generation source) between the meshing surfaces is related to the position in the meshing cycle, the load applied, and the amount of lubricant in the contact. Experimental conditions will be compared to those from the 2-D simulation.
Developments in lubricant technology

CERN Document Server

Srivastava, S P

2014-01-01

Provides a fundamental understanding of lubricants and lubricant technology including emerging lubricants such as synthetic and environmentally friendly lubricants Teaches the reader to understand the role of technology involved in the manufacture of lubricants Details both major industrial oils and automotive oils for various engines Covers emerging lubricant technology such as synthetic and environmentally friendly lubricants Discusses lubricant blending technology, storage, re-refining and condition monitoring of lubricant in equipment
Study of the effect of tribo-materials and surface finish on the lubricant performance of new halogen-free room temperature ionic liquids

Science.gov (United States)

Saurín, N.; Minami, I.; Sanes, J.; Bermúdez, M. D.

2016-03-01

The present work evaluates different materials and surface finish in the presence of newly designed, hydrophobic halogen-free room temperature ionic liquids (RTILs) as lubricants. A reciprocating tribo-tester was employed with steel-ceramic and steel-thermosetting epoxy resin contacts under boundary lubrication conditions. Four different tetraalkylphosphonium organosilanesulfonate RTILs provided excellent lubricating performance, with friction coefficients as low as 0.057, and non-measurable wear for the higher roughness machine-finish stainless steel flat against sapphire balls, in the case of the lubricants containing the 2-trimethylsilylethanesulfonate anion. Higher friction coefficients of the order of 0.1 and wear volumes of the order of 10-4 mm3 were observed for the lower roughness fine-finished flat stainless steel surface. All RTILs prevent wear of epoxy resin against stainless steel balls, with friction coefficients in the range of 0.03-0.06. EDX analysis shows the presence of RTILs on the stainless steel surfaces after the tribological tests. Under the experimental conditions, no corrosive processes were observed.
Squeezing molecularly thin alkane lubrication films: Layering transistions and wear

DEFF Research Database (Denmark)

Sivebæk, Ion Marius; Samoilov, V. N.; Persson, B. N. J.

2004-01-01

The properties of alkane lubricants confined between two approaching solids are investigated by a model that accounts for the curvature and the elastic properties of the solid surfaces. We consider linear alkane molecules of different chain lengths, C(3)H(8); C(4)H(10); C(8)H(18); C(9)H(20); C(10)H...
Lubrication of soft and hard interfaces with thermo-responsive F127 hydrogel

DEFF Research Database (Denmark)

Røn, Troels; Chronakis, Ioannis S.; Lee, Seunghwan

2014-01-01

of F127-20 also displayed varying lubricating properties, both in the lubricating mechanism and efficacy, as a function of temperature, speed and tribopairs. F127-20 was most effective in lubricating a soft interface (PDMSePDMS) based on its gel-forming properties in 22.5-60 °C and feasible formation...
A Review to the Laser Cladding of Self-Lubricating Composite Coatings

Science.gov (United States)

Quazi, M. M.; Fazal, M. A.; Haseeb, A. S. M. A.; Yusof, Farazila; Masjuki, H. H.; Arslan, A.

2016-06-01

Liquid lubricants are extremely viable in reducing wear damage and friction of mating components. However, due to the relentless pressure and the recent trend towards higher operating environments in advanced automotive and aerospace turbo-machineries, these lubricants cease to perform and hence, an alternate system is required for maintaining the self-lubricating environment. From the viewpoint of tribologist, wear is related to near-surface regions and hence, surface coatings are considered suitable for improving the functioning of tribo-pairs. Wear resistant coatings can be fabricated with the addition of various solid lubricants so as to reduce friction drag. In order to protect bulk substrates, self-lubricating wear resistant composite coatings have been fabricated by employing various surface coating techniques such as electrochemical process, physical and chemical vapor depositions, thermal and plasma spraying, laser cladding etc. Studies related to laser-based surface engineering approaches have remained vibrant and are recognized in altering the near surface regions. In this work, the latest developments in laser based self-lubricating composite coatings are highlighted. Furthermore, the effect of additives, laser processing parameters and their corresponding influence on mechanical and tribological performance is briefly reviewed.
A Review of Ionic Liquid Lubricants

Directory of Open Access Journals (Sweden)

Anthony E. Somers

2013-01-01

Full Text Available Due to ever increasing demands on lubricants, such as increased service intervals, reduced volumes and reduced emissions, there is a need to develop new lubricants and improved wear additives. Ionic liquids (ILs are room temperature molten salts that have recently been shown to offer many advantages in this area. The application of ILs as lubricants in a diverse range of systems has found that these materials can show remarkable protection against wear and significantly reduce friction in the neat state. Recently, some researchers have shown that a small family of ILs can also be incorporated into non-polar base oils, replacing traditional anti-wear additives, with excellent performance of the neat IL being maintained. ILs consist of large asymmetrical ions that may readily adsorb onto a metal surface and produce a thin, protective film under boundary lubrication conditions. Under extreme pressure conditions, certain IL compounds can also react to form a protective tribofilm, in particular when fluorine, phosphorus or boron atoms are present in the constituent ions.
A Comparative Study of Face Milling of D2 Steel Using Al2O3 Based Nanofluid Minimum Quantity Lubrication and Minimum Quantity Lubrication

Directory of Open Access Journals (Sweden)

Muhammad Ahsan Ul Haq

2018-03-01

Full Text Available This study aims to investigate the effects of process parameters feed, depth of cut and flow rate, on the temperature during face milling of the D2 tool steel under two different lubricant conditions, Minimum Quantity Lubrication (MQL and Nanofluid Minimum Quantity Lubrication (NFMQL. Distilled water with the flow rate range 200-400 ml/hr was used in MQL. 2% by weight concentration of Al2O3 nanoparticles with distilled water as the base fluid used as NFMQL with same flow rate. Response surface methodology RSM central composite design CCD was used to design experiment run, modeling, and analysis. ANOVA was used for the adequacy and validation of the system. The comparison shows that NFMQL condition reduced more temperature during machining.

Auto-ignition of lubricating oil working at high pressures in a compressor for an air conditioner

Energy Technology Data Exchange (ETDEWEB)

Kim, Chul Jin; Choi, Hyo Hyun [Department of Mechanical Engineering, Sejong University, Seoul 143-747 (Korea, Republic of); Sohn, Chae Hoon, E-mail: chsohn@sejong.ac.kr [Department of Mechanical Engineering, Sejong University, Seoul 143-747 (Korea, Republic of)

2011-01-15

Auto-ignition of lubricating oil working in a compressor for an air conditioner is studied experimentally. The adopted lubricating oil is an unknown mixture with multi-components and known to have flash point temperature of 170 deg. C. First, its auto-ignition temperature is measured 365 deg. C at atmospheric pressure. The lubricating oil works under high-pressure condition up to 30 atm and it is heated and cooled down repeatedly. Accordingly, auto-ignition temperatures or flammable limits of lubricating oil are required at high pressures with respect to fire safety. Because there is not a standard test method for the purpose, a new ignition-test method is proposed in this study and thereby, auto-ignition temperatures are measured over the pressure range below 30 atm. The measured temperatures range from 215 deg. C to 255 deg. C and they strongly depend on pressure of gas mixture consisting of oil vapor, nitrogen, and oxygen. They are close to flash point temperature and the lubricating oil can be hazardous when it works for high-pressure operating condition and abundant air flows into a compressor.
Auto-ignition of lubricating oil working at high pressures in a compressor for an air conditioner

International Nuclear Information System (INIS)

Kim, Chul Jin; Choi, Hyo Hyun; Sohn, Chae Hoon

2011-01-01

Auto-ignition of lubricating oil working in a compressor for an air conditioner is studied experimentally. The adopted lubricating oil is an unknown mixture with multi-components and known to have flash point temperature of 170 deg. C. First, its auto-ignition temperature is measured 365 deg. C at atmospheric pressure. The lubricating oil works under high-pressure condition up to 30 atm and it is heated and cooled down repeatedly. Accordingly, auto-ignition temperatures or flammable limits of lubricating oil are required at high pressures with respect to fire safety. Because there is not a standard test method for the purpose, a new ignition-test method is proposed in this study and thereby, auto-ignition temperatures are measured over the pressure range below 30 atm. The measured temperatures range from 215 deg. C to 255 deg. C and they strongly depend on pressure of gas mixture consisting of oil vapor, nitrogen, and oxygen. They are close to flash point temperature and the lubricating oil can be hazardous when it works for high-pressure operating condition and abundant air flows into a compressor.
Pleural Lubrication

Directory of Open Access Journals (Sweden)

Cristina Porta

2016-05-01

Full Text Available During breathing, the pleural surfaces slide against each other continuously without damage. Pleural liquid and lubricating molecules should provide the lubrication of the sliding surfaces, thus protecting the mesothelium from shear-induced abrasion. D’Angelo et al. (Respir. Physiol. Neurobiol. 2004 measured the coefficient of kinetic friction (μ of rabbit parietal pleura sliding against visceral pleura in vitro at physiological velocities and under physiological loads; it was ~0.02 and did not change with sliding velocity, consistent with boundary lubrication. μ in boundary lubrication can be influenced by surface molecules like hyaluronan, sialomucin or surface active phospholipidis. Hyaluronan or sialomucin is able to restore good boundary lubrication in damaged mesothelium. Nevertheless, hyaluronidase and neuraminidase treatment of the mesothelium does not increase μ, though neuraminidase cleaves sialic acid from the mesothelium. Short pronase or phospholipase treatment, so as to affect only the mesothelial glycocalyx, increases μ, and this increase is removed by hyaluronan or sialomucin. On the other hand, addition of phospholipids after phospholipase treatment produces a small effect relative to that of hyaluronan or sialomucin, and this effect is similar with unsaturated or saturated phospholipids. In damaged mesothelium, the lubrication regimen becomes mixed, but addition of hyaluronan or sialomucin restores boundary lubrication.
Viscous Flow Behaviour of Karanja Oil Based Bio-lubricant Base Oil.

Science.gov (United States)

Sharma, Umesh Chandra; Sachan, Sadhana; Trivedi, Rakesh Kumar

2018-01-01

Karanja oil (KO) is widely used for synthesis of bio-fuel karanja oil methyl ester (KOME) due to its competitive price, good energy values and environmentally friendly combustion properties. Bio-lubricant is another value added product that can be synthesized from KO via chemical modification. In this work karanja oil trimethylolpropane ester (KOTMPE) bio-lubricant was synthesized and evaluated for its viscous flow behaviour. A comparison of viscous flow behaviours of natural KO and synthesized bio-fuel KOME and bio-lubricant KOTMPE was also made. The aim of this comparison was to validate the superiority of KOTMPE bio-lubricant over its precursors KO and KOME in terms of stable viscous flow at high temperature and high shear rate conditions usually encountered in engine operations and industrial processes. The free fatty acid (FFA) content of KO was 5.76%. KOME was synthesized from KO in a two-step, acid catalyzed esterification followed by base catalyzed transesterification, process at 65°C for 5 hours with oil-methanol ratio 1:6, catalysts H 2 SO 4 and KOH (1 and 1.25% w/w KO, respectively). In the final step, KOTMPE was prepared from KOME via transesterification with trimethylolpropane (TMP) at 150°C for 3 hours with KOME-TMP ratio 4:1 and H 2 SO 4 (2% w/w KOME) as catalyst. The viscosity versus temperature studies were made at 0-80°C temperatures in shear rate ranges of 10-1000 s -1 using a Discovery Hybrid Rheometer, model HR-3 (TA instruments, USA). The study found that viscosities of all three samples decreased with increase in temperature, though KOTMPE was able to maintain a good enough viscosity at elevated temperatures due to chemical modifications in its molecular structure. The viscosity index (VI) value for KOTMPE was 206.72. The study confirmed that the synthesized bio-lubricant KOTMPE can be used at high temperatures as a good lubricant, though some additives may be required to improve properties other than viscosity.
Thermo-Rheometric Studies of New Class Ionic Liquid Lubricants

Science.gov (United States)

Bakhtiyarov, Sayavur; Street, Kenneth; Scheiman, Daniel; van Dyke, Alan

2010-11-01

Due to their specific properties, such as small volatility, nonflammability, extreme thermal stability, low melting point, wide liquid range, and good miscibility with organic materials, ionic liquids attracted particular interest in various industrial processes. Recently, the unique properties of ionic liquids caught the attention of space tribologists. The traditional lubricating materials used in space have limited lifetimes in vacuum due to the catalytic degradation on metal surfaces, high vaporization at high temperatures, dewetting, and other disadvantages. The lubricants for the space applications must have vacuum stability, high viscosity index, low creep tendency, good elastohydrodynamic and boundary lubrication properties, radiation atomic oxygen resistance, optical or infrared transparency. Unfortunately, the properties such as heat flow, heat capacity, thermogravimetric weight loss, and non-linearity in the rheological behavior of the lubricants are not studied well for newly developed systems. These properties are crucial to analyzing thermodynamic and energy dissipative aspects of the lubrication process. In this paper we will present the rheological and heat and mass transfer measurements for the ionic liquid lubricants, their mixtures with and without additive.
Using thermal analysis techniques for identifying the flash point temperatures of some lubricant and base oils

Directory of Open Access Journals (Sweden)

Aksam Abdelkhalik

2018-03-01

Full Text Available The flash point (FP temperatures of some lubricant and base oils were measured according to ASTM D92 and ASTM D93. In addition, the thermal stability of the oils was studied using differential scanning calorimeter (DSC and thermogravimetric analysis (TGA under nitrogen atmosphere. The DSC results showed that the FP temperatures, for each oil, were found during the first decomposition step and the temperature at the peak of the first decomposition step was usually higher than FP temperatures. The TGA results indicated that the temperature at which 17.5% weigh loss take placed (T17.5% was nearly identical with the FP temperature (±10 °C that was measured according to ASTM D92. The deviation percentage between FP and T17.5% was in the range from −0.8% to 3.6%. Keywords: Flash point, TGA, DSC
Evaluation of Temperature and Material Combinations on Several Lubricants for Use in the Geostationary Operational Environmental Satellite (GOES) Mission Filter Wheel Bearings

Science.gov (United States)

Jansen, Mark J.; Jones, William R., Jr.; Predmore, Roamer E.

2001-01-01

A bearing test apparatus was used to investigate lubricant degradation rates and elastohydrodynamic transition temperatures for several perfluoropolyether (Krytox) formulations, a pentasilahydrocarbon, and a synthetic hydrocarbon (Pennzane 2001 A) in an MPB 1219 bearing, which is used in the geostationary operational environmental satellite (GOES) mission filter wheel assembly. Test conditions were the following: 1000-hr duration, 75 C, 20 lb axial load, vacuum level less than 1 x 10(exp -6) Torr, and a 600-rpm rotational speed. Baseline tests were performed using unformulated Krytox 143AB, the heritage lubricant. Krytox additive formulations showed small reductions in degradation rate. Krytox GPL-105, a higher viscosity version, yielded the least amount of degradation products. Both the silahydrocarbon and Pennzane 2001A showed no signs of lubricant degradation and had ample amounts of free oil at test conclusion.
Auto-ignition of lubricating oil working at high pressures in a compressor for an air conditioner.

Science.gov (United States)

Kim, Chul Jin; Choi, Hyo Hyun; Sohn, Chae Hoon

2011-01-15

Auto-ignition of lubricating oil working in a compressor for an air conditioner is studied experimentally. The adopted lubricating oil is an unknown mixture with multi-components and known to have flash point temperature of 170 °C. First, its auto-ignition temperature is measured 365 °C at atmospheric pressure. The lubricating oil works under high-pressure condition up to 30 atm and it is heated and cooled down repeatedly. Accordingly, auto-ignition temperatures or flammable limits of lubricating oil are required at high pressures with respect to fire safety. Because there is not a standard test method for the purpose, a new ignition-test method is proposed in this study and thereby, auto-ignition temperatures are measured over the pressure range below 30 atm. The measured temperatures range from 215 °C to 255 °C and they strongly depend on pressure of gas mixture consisting of oil vapor, nitrogen, and oxygen. They are close to flash point temperature and the lubricating oil can be hazardous when it works for high-pressure operating condition and abundant air flows into a compressor. Copyright © 2010 Elsevier B.V. All rights reserved.
Double hollow MoS{sub 2} nano-spheres: Synthesis, tribological properties, and functional conversion from lubrication to photocatalysis

Energy Technology Data Exchange (ETDEWEB)

Liu, Yueru [Department of Chemical and Materials Engineering, Hefei University, Hefei 230601 (China); Hu, Kunhong, E-mail: hukunhong@163.com [Department of Chemical and Materials Engineering, Hefei University, Hefei 230601 (China); Hu, Enzhu; Guo, Jianhua; Han, Chengliang [Department of Chemical and Materials Engineering, Hefei University, Hefei 230601 (China); Hu, Xianguo [Institute of Tribology, Hefei University of Technology, Hefei 230009 (China)

2017-01-15

Highlights: • Novel double-hollow-sphere MoS{sub 2} nanoparticles were synthesized on sericite. • Friction and wear decreased by 22.4 and 63.5% by the novel MoS{sub 2}/sericite. • Friction induced conversion of MoS{sub 2}/sericite from lubricant to catalyst. • MoS{sub 2}/sericite can be used as a photocatalyst after lubricating service life. • A possible approach was proposed for designing a novel green lubricant. - Abstract: Molybdenum disulfide (MoS{sub 2}) has extensive applications in industries as solid lubricants and catalysts. To improve the lubricating performance of MoS{sub 2}, novel double-hollow-sphere MoS{sub 2} (DHSM) nanoparticles with an average diameter of approximately 90 nm were synthesized on sericite mica (SM). When the DHSM/SM composite was used as an additive in polyalphaolefin oil, friction and wear decreased by 22.4% and 63.5% respectively. The low friction and wear were attributed to the easy exfoliation of DHSM. The DHSM/SM composite was then rubbed under 40 MPa for 1 h to investigate the exfoliation and functional conversion behaviors of DHSM. Results showed that DHSM (lubricating structure) on SM could be completely exfoliated into nanosheets (catalytic structure) by rubbing. The nanosheets exfoliated from DHSM presented good photocatalytic activity for the removal of organic compounds from waste water. This work provided both a novel solid lubricant for industrial applications and a possible approach to designing a novel green lubricant for use as a photocatalyst in organic-waste treatment after lubricating service life.
Compressibilities and viscosities of reference, vegetable, and synthetic gear lubricants

DEFF Research Database (Denmark)

Regueira Muñiz, Teresa; Lugo, Luis; Fernández, Josefa

2014-01-01

Nowadays, one of the primary choices of base oils for environmentally aware lubricants is vegetable oils. This is due to their good natural biodegradability and very low toxicity in combination with very good lubricity characteristics. The development of new vegetable-based lubricants requires...... values of six gear lubricants, two of them reference mineral oils and the other four developed biodegradable oils based in high oleic sunflower oil or in synthetic esters. It was found that all of the lubricants have both similar compressibilities and similar expansivities. Dowson and Higginson, Zhu.......06%. Dowson and Higginson and Zhu and Wen equations of state do not predict well the isothermal compressibilities, with AAD % being around 45% for both equations. Moreover, the viscosities were measured in the temperature range from 278.15 to 373.15 K at atmospheric pressure for these oils, and the viscosity...
Compatibility of refrigerants and lubricants with elastomers. Final report

Energy Technology Data Exchange (ETDEWEB)

Hamed, G.R.; Seiple, R.H.; Taikum, Orawan

1994-01-01

The information contained in this report is designed to assist the air-conditioning and refrigeration industry in the selection of suitable elastomeric gasket and seal materials that will prove useful in various refrigerant and refrigeration lubricant environments. In part I of the program the swell behavior in the test fluids has been determined using weight and in situ diameter measurements for the refrigerants and weight, diameter and thickness measurements for the lubricants. Weight and diameter measurements are repeated after 2 and 24 hours for samples removed fro the refrigerant test fluids and 24 hours after removal from the lubricants. Part II of the testing program includes the evaluation of tensile strength, hardness, weight, and dimensional changes after immersion aging in refrigerant/lubricant mixtures of selected elastomer formulations at elevated temperature and pressure.
Studies on Thermal Oxidation Stability of Aviation Lubricating Oils

Directory of Open Access Journals (Sweden)

Wu Nan

2017-01-01

Full Text Available Simulating the operating condition of aviation engine via autoclave experiment of high temperature and pressure, we studied the physic-chemical property of poly-α-olefin base oil samples mixed with antioxidants of 2,6-di-tert-butyl-4-methylphenol and p,p’-diisooctyl diphenylamine at different temperature. The mechanism of degradation of PAO aviation lubricating oil was analyzed according to the oxidized products by modern analytical instruments. The results showed that the aviation lubricating oil produced a large number of low molecule compounds while increasing the temperature, and resulted in the viscosity decreasing and acid value increasing which indicated that the thermal oxidation of the oil sample underwent a radical process.
Regeneration of used lubricating oil as a source of energy

Directory of Open Access Journals (Sweden)

A. T. Abdulrahim

2001-10-01

Full Text Available Conservation of natural resources by refining used lubricating oil was attempted in this work. Used lubricating oil was purified and distilled. The distillates obtained were divided into two temperature ranges of 60 - 210°C and 210 - 310°C. Analyses of the physicochemical properties of the two samples revealed that they have similar properties with gasoline and diesel fuels respectively. This result shows that used lubricating oils, which are usually regarded as waste, can be regenerated to obtain useful hydrocarbons that can be used as fuels to power internal combustion engines
Glass transitions in lubricants - Its relation to elastohydrodynamic lubrication /EHD/

Science.gov (United States)

Alsaad, M.; Bair, S.; Sanborn, D. M.; Winer, W. O.

1977-01-01

A preliminary investigation into the possible role of glass transition and glassy state behavior of lubricants in EHD contacts is reported. Measurements of the glass transition of lubricants as a function of pressure by two methods are presented along with a discussion indicating possible implications of the results to EHD lubrication.
Lubrication performance and mechanisms of Mg/Al-, Zn/Al-, and Zn/Mg/Al-layered double hydroxide nanoparticles as lubricant additives

International Nuclear Information System (INIS)

Li, Shuo; Bhushan, Bharat

2016-01-01

Highlights: • Mg/Al-, Zn/Al- and Zn/Mg/Al-layered double hydroxide were synthesized. • Mg/Al-LDH had superior tribological performance compared to other LDHs. • The best thermal stability of Mg/Al-LDH was responsible for its friction property. - Abstract: Solid lubricant particles are commonly used as oil additives for low friction and wear. Mg/Al-, Zn/Al-, and Zn/Mg/Al-layered double hydroxides (LDH) were synthesized by coprecipitation method. The benefits of LDH nanoparticles are that they can be synthesized using chemical methods where size and shape can be controlled, and can be modified organically to allow dispersal in fluids. The LDH nanoparticles were characterized by X-ray diffraction, scanning electron microscope, thermogravimetry, and differential scanning calorimetry. A pin-on-disk friction and wear tester was used for evaluating the friction and wear properties of LDH nanoparticles as lubricant additives. LDH nanoparticles have friction-reducing and anti-wear properties compared to oil without LDHs. Mg/Al-LDH has the best lubrication, possibly due to better thermal stability in severe conditions.
Lubrication performance and mechanisms of Mg/Al-, Zn/Al-, and Zn/Mg/Al-layered double hydroxide nanoparticles as lubricant additives

Energy Technology Data Exchange (ETDEWEB)

Li, Shuo [School of Materials Science and Technology, China University of Geosciences (Beijing), 29 Xueyuan Road, Haidian Distract, Beijing 100083 (China); Nanoprobe Laboratory for Bio- & Nanotechnology and Biomimetics (NLBB), The Ohio State University, 201 W. 19th Avenue Columbus, OH 43210-1142 (United States); Bhushan, Bharat, E-mail: bhushan.2@osu.edu [Nanoprobe Laboratory for Bio- & Nanotechnology and Biomimetics (NLBB), The Ohio State University, 201 W. 19th Avenue Columbus, OH 43210-1142 (United States)

2016-08-15

Highlights: • Mg/Al-, Zn/Al- and Zn/Mg/Al-layered double hydroxide were synthesized. • Mg/Al-LDH had superior tribological performance compared to other LDHs. • The best thermal stability of Mg/Al-LDH was responsible for its friction property. - Abstract: Solid lubricant particles are commonly used as oil additives for low friction and wear. Mg/Al-, Zn/Al-, and Zn/Mg/Al-layered double hydroxides (LDH) were synthesized by coprecipitation method. The benefits of LDH nanoparticles are that they can be synthesized using chemical methods where size and shape can be controlled, and can be modified organically to allow dispersal in fluids. The LDH nanoparticles were characterized by X-ray diffraction, scanning electron microscope, thermogravimetry, and differential scanning calorimetry. A pin-on-disk friction and wear tester was used for evaluating the friction and wear properties of LDH nanoparticles as lubricant additives. LDH nanoparticles have friction-reducing and anti-wear properties compared to oil without LDHs. Mg/Al-LDH has the best lubrication, possibly due to better thermal stability in severe conditions.
Effect of Argon Flow Rate on the Tribological Performance of Self-lubricating WS2/a-C Sputtered Coating

NARCIS (Netherlands)

Cao, Huatang; De Hosson, J.T.M.; Pei, Yutao T.

2016-01-01

Layered transition metal dichalcogenides (TMD) such as WS2 are well-known materials for their solid lubricating properties [1]. However, the lubricating performance degrades through oxidation or moisture and it is also limited by its low load-bearing capacity. In contrast amorphous diamond-like
Full Life Wind Turbine Gearbox Lubricating Fluids

Energy Technology Data Exchange (ETDEWEB)

Lutz, Glenn A.; Jungk, Manfred; Bryant, Jonathan J.; Lauer, Rebecca S.; Chobot, Anthony; Mayer, Tyler; Palmer, Shane; Kauffman, Robert E.

2012-02-28

Industrial gear box lubricants typically are hydrocarbon based mineral oils with considerable amounts of additives to overcome the lack of base fluid properties like wear protection, oxidation stability, load carrying capacity, low temperature solidification and drop of viscosity at higher temperatures. For today's wind turbine gearboxes, the requirements are more severe and synthetic hydrocarbon oils are used to improve on this, but all such hydrocarbon based lubricants require significant amounts of Extreme Pressure (EP) additives to meet performance requirements. Perfluoropolyether (PFPE) fluids provide load carrying capacity as an inherent property. During the course of the project with the main tasks of 'Establish a Benchmark', 'Lubricant Evaluation', 'Full Scale Gearbox Trial' and 'Economic Evaluation', the PAO Reference oil exhibited significant changes after laboratory gear testing, in service operation in the field and full scale gearbox trial. Four hydrocarbon base oils were selected for comparison in the benchmarking exercise and showed variation with respect to meeting the requirements for the laboratory micro-pitting tests, while the PFPE fluid exceeded the requirements even with the material taken after the full scale gear box trial. This is remarkable for a lubricant without EP additives. Laboratory bearing tests performed on the PFPE fluids before and after the full scale gear box trial showed the results met requirements for the industry standard. The PFPE fluid successfully completed the full scale gear box test program which included baseline and progressive staged load testing. The evaluation of gears showed no micro-pitting or objectionable wear. By the final stage, lubricant film thickness had been reduced to just 21% of its original value, this was by design and resulted in a lambda ratio of well below 1. This test design scenario of a low lambda ratio is a very undesirable lubrication condition
The role of lubricant analysis in maximizing lubricant and equipment life

International Nuclear Information System (INIS)

Janis, J.

1995-01-01

Lubricant analysis has always played an important yet somewhat invisible role in equipment health monitoring. At its most primitive, simple observations and field testing alert equipment operators to changing conditions. At its most advanced, data from performance and analytical tests are used to develop or select optimum lubricants for service, stretch drain intervals, predict remaining equipment life and identify potential equipment or system problems at an incipient stage. Coupled with thermography and vibration analysis, lubricant analysis can become a major component of a comprehensive predictive maintenance (PM) program. Ontario Hydro finds itself at a turning point regarding the use and monitoring of lubricants. Increasing emphasis on equipment reliability and plant life extension, coupled with major, recent changes in lubricant composition in response to environmental, energy and safety concerns, forces an upgrading of many aspects of lubricant monitoring so that it may establish itself as a key part of modern PM practices. This paper discusses some of these aspects. (author)
Re-Refining of Waste Lubricating Oil by Solvent Extraction

Directory of Open Access Journals (Sweden)

Hassan Ali Durrani

2011-04-01

Full Text Available Re-refining of waste lubricating oil by solvent extraction is one of the potential techniques. The advantages of solvent extraction technique practically offers from environmental and economic points of view have received due attention. In this paper selection of composite solvent and technique to upgrade the used lubricant oil into base oil has been made. The composite solvent 2-propanol, 1-butanol and butanone have two alcohols that make a binary system reasonably effective. This work also attempts to study the performance of the composite solvent in the extraction process for recovering waste lubricating oil. The key parameters considered were vacuum pressure, temperature and the weight ratio of solvent to waste lubricating oil. The performance was investigated on the PSR (Percentage Sludge Removal and POL (Percent Oil Loss. The best results were obtained using composite solvent 25% 2-propanol, 37% 1-butanol and 38% butanone by a solvent to oil ratio of 6:1 at vacuum pressure 600mmHg and distillation temperature 250oC. The vacuum distilled oil pretreated with the composite solvents was matched to the standard base oil 500N and 150N, found in close agreement and could be used for similar purpose.

A fundamental investigation into the relationship between lubricant composition and fuel ignition quality

KAUST Repository

Kuti, Olawole Abiola

2015-11-01

A fundamental experiment involving the use of an ignition quality tester (IQT) was carried out to elucidate the effects of lubricant oil composition which could lead to low speed pre-ignition (LSPI) processes in direct injection spark ignition (DISI) engines. Prior to the IQT tests, lubricant base oils were analyzed using ultra-high resolution mass spectrometry to reveal their molecular composition. High molecular-weight hydrocarbons such as nC16H34, nC17H36, and nC18H38 were selected as surrogates of lubricant base oil constituents, and then mixed with iso-octane (iC8H18-gasoline surrogate) in proportions of 1 vol.% (iC8H18 = 99 vol.%) and 10 vol.% (iC8H18 = 90 vol.%) for the IQT experiments. In addition, lubricant base oils such as SN100 (Group I) and HC4 and HC6 (Group III) and a fully formulated lubricant (SAE 20W50) were mixed with iso-octane in the same proportions. The IQT results were conducted at an ambient pressure of 15 bar and a temperature range of 680-873 K. In the temperature range of 710-850 K, the addition of 10 vol.% base oils surrogates, base oils, and lubricating oil to the 90 vol.% iC8H18 reduces the average total ignition delay time by up to 54% for all mixtures, while the addition of 1 vol.% to 99 vol.% iC8H18 yielded a 7% reduction within the same temperature range. The shorter total ignition delay was attributed to the higher reactivity of the lubricant base oil constituents in the fuel mixtures. A correlation between reactivity of base oils and their molecular composition was tentatively established. These results suggest that the lubricants have the propensity of initiating LSPI in DISI engines. Furthermore, similar results for n-alkanes, lubricant base oils, and fully formulated commercial lubricants suggest that it is the hydrocarbon fraction that contributes primarily to enhanced reactivity, and not the inorganic or organometallic additives. © 2015 Elsevier Ltd. All rights reserved.
A fundamental investigation into the relationship between lubricant composition and fuel ignition quality

KAUST Repository

Kuti, Olawole Abiola; Yang, Seung Yeon; Hourani, Nadim; Naser, Nimal; Roberts, William L.; Chung, Suk-Ho; Sarathy, Mani

2015-01-01

A fundamental experiment involving the use of an ignition quality tester (IQT) was carried out to elucidate the effects of lubricant oil composition which could lead to low speed pre-ignition (LSPI) processes in direct injection spark ignition (DISI) engines. Prior to the IQT tests, lubricant base oils were analyzed using ultra-high resolution mass spectrometry to reveal their molecular composition. High molecular-weight hydrocarbons such as nC16H34, nC17H36, and nC18H38 were selected as surrogates of lubricant base oil constituents, and then mixed with iso-octane (iC8H18-gasoline surrogate) in proportions of 1 vol.% (iC8H18 = 99 vol.%) and 10 vol.% (iC8H18 = 90 vol.%) for the IQT experiments. In addition, lubricant base oils such as SN100 (Group I) and HC4 and HC6 (Group III) and a fully formulated lubricant (SAE 20W50) were mixed with iso-octane in the same proportions. The IQT results were conducted at an ambient pressure of 15 bar and a temperature range of 680-873 K. In the temperature range of 710-850 K, the addition of 10 vol.% base oils surrogates, base oils, and lubricating oil to the 90 vol.% iC8H18 reduces the average total ignition delay time by up to 54% for all mixtures, while the addition of 1 vol.% to 99 vol.% iC8H18 yielded a 7% reduction within the same temperature range. The shorter total ignition delay was attributed to the higher reactivity of the lubricant base oil constituents in the fuel mixtures. A correlation between reactivity of base oils and their molecular composition was tentatively established. These results suggest that the lubricants have the propensity of initiating LSPI in DISI engines. Furthermore, similar results for n-alkanes, lubricant base oils, and fully formulated commercial lubricants suggest that it is the hydrocarbon fraction that contributes primarily to enhanced reactivity, and not the inorganic or organometallic additives. © 2015 Elsevier Ltd. All rights reserved.
Predictive modelling of fatigue failure in concentrated lubricated contacts.

Science.gov (United States)

Evans, H P; Snidle, R W; Sharif, K J; Bryant, M J

2012-01-01

Reducing frictional losses in response to the energy agenda will require use of less viscous lubricants causing hydrodynamically-lubricated bearings to operate with thinner films leading to "mixed lubrication" conditions in which a degree of direct interaction occurs between surfaces protected only by boundary tribofilms. The paper considers the consequences of thinner films and mixed lubrication for concentrated contacts such as those occurring between the teeth of power transmission gears and in rolling element bearings. Surface fatigue in gears remains a serious problem in demanding applications, and its solution will become more pressing with the tendency towards thinner oils. The particular form of failure examined here is micropitting, which is identified as a fatigue phenomenon occurring at the scale of the surface roughness asperities. It has emerged recently as a systemic difficulty in the operation of large scale wind turbines where it occurs in both power transmission gears and their support bearings. Predictive physical modelling of these contacts requires a transient mixed lubrication analysis for conditions in which the predicted lubricant film thickness is of the same order or significantly less than the height of surface roughness features. Numerical solvers have therefore been developed which are able to deal with situations in which transient solid contacts occur between surface asperity features under realistic engineering conditions. Results of the analysis, which reveal the detailed time-varying behaviour of pressure and film clearance, have been used to predict fatigue and damage accumulation at the scale of surface asperity features with the aim of improving understanding of the micropitting phenomenon. The possible consequences on fatigue of residual stress fields resulting from plastic deformation of surface asperities is also considered.
De-Lubrication Behavior Of Novel EBS Based Admixed Lubricant In Aluminum P/M Alloy

Directory of Open Access Journals (Sweden)

Oh M.C.

2015-06-01

Full Text Available The objective of the present research is to develop a novel lubricant for Al-Cu-Mg P/M alloy and to address the effects of the lubricant and compaction pressure on sintered properties. A lubricant mixture consisting of Ethylene Bis Stearamide, Zn-Stearate, and fatty acid was newly developed in this study, and the de-lubrication behavior was compared with that of other commercial lubricants, such as Ethylene Bis Stearamide, Zn-Stearate, and Al-Stearate. Density and transverse rupture strength of sintered materials with each lubricant were examined, respectively. The microstructural analysis was conducted using optical microscope.
Grease lubrication in rolling bearings

CERN Document Server

Lugt, Piet M

2012-01-01

The definitive book on the science of grease lubrication for roller and needle bearings in industrial and vehicle engineering. Grease Lubrication in Rolling Bearings provides an overview of the existing knowledge on the various aspects of grease lubrication (including lubrication systems) and the state of the art models that exist today. The book reviews the physical and chemical aspects of grease lubrication, primarily directed towards lubrication of rolling bearings. The first part of the book covers grease composition, properties and rheology, including thermal
Effects of carbon content and argon flow rate on the triboperformance of self-lubricating WS2/a-C sputtered coating

NARCIS (Netherlands)

Cao, Huatang; De Hosson, J.T.M.; Pei, Yutao T.

2017-01-01

Layered transition metal dichalcogenides (TMD) such as WS2 are materials well-known for their solid lubrication properties [1]. However, the lubricating property degrades through oxidation or moisture and it is also limited by its low hardness and low load-bearing capacity. In contrast amorphous
Development of the water-lubricated thrust bearing of the hydraulic turbine generator

International Nuclear Information System (INIS)

Inoue, K; Deguchi, K; Okude, K; Fujimoto, R

2012-01-01

In hydropower plant, a large quantities of turbine oil is used as machine control pressure oil and lubricating oil. If the oil leak out from hydropower plant, it flows into a river. And such oil spill has an adverse effect on natural environment because the oil does not degrade easily. Therefore the KANSAI and Hitachi Mitsubishi Hydro developed the water-lubricated thrust bearing for vertical type hydraulic turbine generator. The water-lubricated bearing has advantages in risk avoidance of river pollution because it does not need oil. For proceeding the development of the water-lubricated thrust bearing, we studied following items. The first is the examination of the trial products of water lubricating liquid. The second is the study of bearing structure which can satisfy bearing performance such as temperature characteristic and so on. The third is the mock-up testing for actual application in the future. As a result, it was found that the water-lubricated thrust bearing was technically applicable to actual equipments.
Influence of Stern Shaft Inclination on the Cooling Performance of Water-Lubricated Bearing

Directory of Open Access Journals (Sweden)

Zou Li

2016-01-01

Full Text Available The water film model of the marine water-lubricated stern bearing was established by FLUENT. The influence law of water flow rate on the cooling performance of water-lubricated bearing was studied in consideration of the stern shaft inclination. It will be helpful to improve the performance of marine water-lubricated stern bearing and both security and reliability of propulsion system. The simulation results show that the increase of cooling water flow rate in a certain range can effectively reduce bearing temperature. The bearing temperature rises sharply with thinning of water film thickness which is caused by the increase of inclination angle. Larger inclination angle can deteriorate the operating reliability of bearing.
On the lubrication mechanism of detonation-synthesis nanodiamond additives in lubricant composites

Science.gov (United States)

Shepelevskii, A. A.; Esina, A. V.; Voznyakovskii, A. P.; Fadin, Yu. A.

2017-09-01

The lubrication of detonation-synthesis diamond additives in lubricant composites has been discussed. The mechanism of interaction between nanodiamonds and friction surface has been shown to depend on the applied load. Two models of the lubrication of nanodiamonds and the conditions for their validity have also been proposed.
Assessment of a lubricant based nanofluid application in a rotary system

International Nuclear Information System (INIS)

Hajmohammadi, M.R.

2017-01-01

Highlights: • Application of metallic nanoparticles in a rotary system is evaluated. • Evaluations are based on first and second laws of thermodynamics. • Two-phase numerical method is used and lubricant is considered inhomogeneous. • Nanoparticles with limited concentricity in lowspeed rotary system are recommended. - Abstract: Rotary systems and nanofluids are frequently used in energy conversion and management systems. In this paper, a numerical study is performed to evaluate the application of metallic nano-particles in a rotary system filled with a lubricant from first and second laws of thermodynamics points of view. The nano-lubricant (lubricant based nanofluid) is considered inhomogeneous with dependent transport properties on nano-particles volume fraction, nano-particles size and the temperature. A two-phase model is undertaken to account for the Brownian motion and thermophoresis diffusion. The principal objective centers in the advantages and penalties of using nano-lubricant over the pure lubricant on the basis of first and second law (of thermodynamics). The numerical results demonstrate that the nano-particles enhance the thermal performance of the rotary system. However, undesirable aspect from hydro-dynamical and second law (of thermodynamic) perspectives are reported. While a nano-lubricant with limited volume fraction in low speed rotary system is recommended, the disadvantages of nano-lubricants with high volume fractions and/or used in a high-speed rotary system are dominant to nano-lubricants advantages and must be avoided.
Fault lubrication during earthquakes.

Science.gov (United States)

Di Toro, G; Han, R; Hirose, T; De Paola, N; Nielsen, S; Mizoguchi, K; Ferri, F; Cocco, M; Shimamoto, T

2011-03-24

The determination of rock friction at seismic slip rates (about 1 m s(-1)) is of paramount importance in earthquake mechanics, as fault friction controls the stress drop, the mechanical work and the frictional heat generated during slip. Given the difficulty in determining friction by seismological methods, elucidating constraints are derived from experimental studies. Here we review a large set of published and unpublished experiments (∼300) performed in rotary shear apparatus at slip rates of 0.1-2.6 m s(-1). The experiments indicate a significant decrease in friction (of up to one order of magnitude), which we term fault lubrication, both for cohesive (silicate-built, quartz-built and carbonate-built) rocks and non-cohesive rocks (clay-rich, anhydrite, gypsum and dolomite gouges) typical of crustal seismogenic sources. The available mechanical work and the associated temperature rise in the slipping zone trigger a number of physicochemical processes (gelification, decarbonation and dehydration reactions, melting and so on) whose products are responsible for fault lubrication. The similarity between (1) experimental and natural fault products and (2) mechanical work measures resulting from these laboratory experiments and seismological estimates suggests that it is reasonable to extrapolate experimental data to conditions typical of earthquake nucleation depths (7-15 km). It seems that faults are lubricated during earthquakes, irrespective of the fault rock composition and of the specific weakening mechanism involved.
Ball Bearings Equipped for In Situ Lubrication on Demand

Science.gov (United States)

Marchetti, Mario; Jones, William R., Jr.; Pepper, Stephen V.; Jansen, Mark; Predmore, Roamer

2005-01-01

In situ systems that provide fresh lubricants to ball/race contacts on demand have been developed to prolong the operational lives of ball bearings. These systems were originally intended to be incorporated into ball bearings in mechanisms that are required to operate in outer space for years, in conditions in which lubricants tend to deteriorate and/or evaporate. These systems may also be useful for similarly prolonging bearing lifetimes on Earth. Reservoirs have been among the means used previously to resupply lubricants. Lubricant- resupply reservoirs are bulky and add complexity to bearing assemblies. In addition, such a reservoir cannot be turned on or off as needed: it supplies lubricant continuously, often leading to an excess of lubricant in the bearing. A lubricator of the present type includes a porous ring cartridge attached to the inner or the outer ring of a ball bearing (see Figure 1). Oil is stored in the porous cartridge and is released by heating the cartridge: Because the thermal expansion of the oil exceeds that of the cartridge, heating causes the ejection of some oil. A metal film can be deposited on a face of the cartridge to serve as an electrical-resistance heater. The heater can be activated in response to a measured increase in torque that signals depletion of oil from the bearing/race contacts. Because the oil has low surface tension and readily wets the bearing-ring material, it spreads over the bearing ring and eventually reaches the ball/race contacts. The Marangoni effect (a surface-tension gradient associated with a temperature gradient) is utilized to enhance the desired transfer of lubricant to the ball/race contacts during heating. For a test, a ball bearing designed for use at low speed was assembled without lubricant and equipped with a porous-ring lubricator, the resistance heater of which consumed a power of less than 1 W when triggered on by a torque-measuring device. In the test, a load of 20 lb (.89 N) was applied and the
Evaluation of replacement thread lubricants for red lead and graphite in mineral oil

Energy Technology Data Exchange (ETDEWEB)

Jungling, T.L.; Rauth, D.R.; Goldberg, D.

1998-04-30

Eight commercially available thread lubricants were evaluated to determine the best replacement for Red Lead and Graphite in Mineral Oil (RLGMO). The evaluation included coefficient of friction testing, high temperature anti-seizing testing, room temperature anti-galling testing, chemical analysis for detrimental impurities, corrosion testing, off-gas testing, and a review of health and environmental factors. The coefficient of friction testing covered a wide variety of factors including stud, nut, and washer materials, sizes, manufacturing methods, surface coatings, surface finishes, applied loads, run-in cycles, and relubrication. Only one lubricant, Dow Corning Molykote P37, met all the criteria established for a replacement lubricant. It has a coefficient of friction range similar to RLGMO. Therefore, it can be substituted directly for RLGMO without changing the currently specified fastener torque values for the sizes, materials and conditions evaluated. Other lubricants did not perform as well as Molykote P37 in one or more test or evaluation categories.
14 CFR 33.71 - Lubrication system.

Science.gov (United States)

2010-01-01

... arranged that condensed water vapor that might freeze and obstruct the line cannot accumulate at any point... fireproof. (9) Each unpressurized oil tank may not leak when subjected to a maximum operating temperature... supply becomes depleted due to failure of any part of the lubricating system other than the tank itself...
Frictional characteristics of silicon graphite lubricated with water at high pressure and high temperature

International Nuclear Information System (INIS)

Lee, Jae Seon; Kim, Eun Hyun; Park, Jin Seok; Kim, Jong In

2001-01-01

Experimental frictional and wear characteristics of silicon graphite materials is studied in this paper. Those specimens are lubricated with high temperature and highly pressurized water to simulate the same operating condition for the journal bearing and the thrust bearing on the main coolant pump bearing in the newly developing nuclear reactor named SMART(System-integrated Modular Advanced ReacTor). Operating condition of the bearings is realized by the tribometer and the autoclave. Friction coefficient and wear loss are analyzed to choose the best silicon graphite material. Pin on plate test specimens are used and coned disk springs are used to control the applied force on the specimens. Wear loss and wear width are measured by a precision balance and a micrometer. The friction force is measured by the strain gauge which can be used under high temperature and high pressure. Three kinds of silicon graphite materials are examined and compared with each other, and each material shows similar but different results on frictional and wear characteristics
Study of the Thermal Decomposition of PFPEs Lubricants on a Thin DLC Film Using Finitely Extensible Nonlinear Elastic Potential Based Molecular Dynamics Simulation

International Nuclear Information System (INIS)

Deb Nath, S.K.; Deb Nath, S.K.; Wong, C.H.; Deb Nath, S.K.

2014-01-01

Perfluoro polyethers (PFPEs) are widely used as hard disk lubricants for protecting carbon overcoat reducing friction between the hard disk interface and the head during the movement of head during reading and writing data in the hard disk. Due to temperature rise of PFPE Zdol lubricant molecules on a DLC surface, how polar end groups are detached from lubricant molecules during coating is described considering the effect of temperatures on the bond/break density of PFPE Zdol using the coarse-grained bead spring model based on finitely extensible nonlinear elastic potential. As PFPE Z contains no polar end groups, effects of temperature on the bond/break density (number of broken bonds/total number of bonds) are not so significant like PFPE Zdol. Effects of temperature on the bond/break density of PFPE Z on DLC surface are also discussed with the help of graphical results. How bond/break phenomenon affects the end bead density of PFPE Z and PFPE Zdol on DLC surface is discussed elaborately. How the overall bond length of PFPE Zdol increases with the increase of temperature which is responsible for its decomposition is discussed with the help of graphical results. At HAMR condition, as PFPE Z and PFPE Zdol are not suitable lubricant on a hard disk surface, it needs more investigations to obtain suitable lubricant. We study the effect of breaking of bonds of nonfunctional lubricant PFPE Z, functional lubricants such as PFPE Zdol and PFPE Ztetrao, and multi dented functional lubricants such as Ar-DS, ARJ-DD, and OHJ-DS on a DLC substrate with the increase of temperature when heating of all of the lubricants on a DLC substrate is carried out isothermally using the coarse-grained bead spring model by molecular dynamics simulations and suitable lubricant is selected which is suitable on a DLC substrate at high temperature.
Study of the Thermal Decomposition of PFPEs Lubricants on a Thin DLC Film Using Finitely Extensible Nonlinear Elastic Potential Based Molecular Dynamics Simulation

Directory of Open Access Journals (Sweden)

S. K. Deb Nath

2014-01-01

Full Text Available Perfluoropolyethers (PFPEs are widely used as hard disk lubricants for protecting carbon overcoat reducing friction between the hard disk interface and the head during the movement of head during reading and writing data in the hard disk. Due to temperature rise of PFPE Zdol lubricant molecules on a DLC surface, how polar end groups are detached from lubricant molecules during coating is described considering the effect of temperatures on the bond/break density of PFPE Zdol using the coarse-grained bead spring model based on finitely extensible nonlinear elastic potential. As PFPE Z contains no polar end groups, effects of temperature on the bond/break density (number of broken bonds/total number of bonds are not so significant like PFPE Zdol. Effects of temperature on the bond/break density of PFPE Z on DLC surface are also discussed with the help of graphical results. How bond/break phenomenonaffects the end bead density of PFPE Z and PFPE Zdol on DLC surface is discussed elaborately. How the overall bond length of PFPE Zdol increases with the increase of temperature which is responsible for its decomposition is discussed with the help of graphical results. At HAMR condition, as PFPE Z and PFPE Zdol are not suitable lubricant on a hard disk surface, it needs more investigations to obtain suitable lubricant. We study the effect of breaking of bonds of nonfunctional lubricant PFPE Z, functional lubricants such as PFPE Zdol and PFPE Ztetrao, and multidented functional lubricants such as ARJ-DS, ARJ-DD, and OHJ-DS on a DLC substrate with the increase of temperature when heating of all of the lubricants on a DLC substrate is carried out isothermally using the coarse-grained bead spring model by molecular dynamics simulations and suitable lubricant is selected which is suitable on a DLC substrate at high temperature.
Towards an accurate and precise determination of the solid-solid transition temperature of enantiotropic systems

Energy Technology Data Exchange (ETDEWEB)

Herman, Christelle, E-mail: christelle.herman@ulb.ac.b [Universite Libre de Bruxelles, Transfers, Interfaces and Processes Department, Chemical Engineering Unit, 50 Avenue Franklin D-Roosevelt, CP 165/67, 1050 Bruxelles (Belgium); Leyssens, Tom [Universite Catholique de Louvain, Institute of Condensed Matter and Nanosciences, 1 Place Louis Pasteur, 1348 Louvain-La-Neuve (Belgium); Vermylen, Valerie [UCB Pharma, 60 Allee de la Recherche, 1070 Braine l' Alleud (Belgium); Halloin, Veronique; Haut, Benoit [Universite Libre de Bruxelles, Transfers, Interfaces and Processes Department, Chemical Engineering Unit, 50 Avenue Franklin D-Roosevelt, CP 165/67, 1050 Bruxelles (Belgium)

2011-05-15

Research highlights: We test two methods to obtain the solid-solid transition temperature of Etiracetam system, showing two enantiotropically related polymorphs. The first method, based on a thermodynamic development, is sensitive to the correctness of the data required. The second method is an experimental study of the stability thermal range of each morph. We identify the nature of crystals in suspension at equilibrium through Raman analysis. The solid-solid transition temperature is found equal to 303.65 K {+-} 0.5 K. - Abstract: This paper presents two distinct methods for the determination of the solid-solid transition temperature (T{sub tr}) separating the temperature ranges of stability of two crystallographic forms, hereafter called morphs, of a same substance. The first method, based on thermodynamic calculations, consists in determining T{sub tr} as the temperature at which the Gibbs free energies of the two morphs are equal to each other. For this purpose, some thermodynamic characteristics of both morphs are required, such as the specific heat capacities, the melting temperatures and the melting enthalpies. These are obtained using the Differential Scanning Calorimetry (DSC). In the second method, T{sub tr} is determined directly by an experimental study of the temperature ranges of stability of each morph. The three main originalities of the method developed are (i) to prepare samples composed by an isomassic mixture of crystals of both morphs, (ii) to set them in a thermostated and agitated suspension, and (iii) to use an in situ Raman spectroscopic probe for the determination of the crystallographic form of the crystals in suspension at equilibrium. Both methods are applied to determine the solid-solid transition temperature of the enantiotropic system of Etiracetam, and both of its two crystallographic forms so far identified, named morph I and morph II. The first method is shown to be very sensitive to the experimental data obtained by DSC while
Towards an accurate and precise determination of the solid-solid transition temperature of enantiotropic systems

International Nuclear Information System (INIS)

Herman, Christelle; Leyssens, Tom; Vermylen, Valerie; Halloin, Veronique; Haut, Benoit

2011-01-01

Research highlights: → We test two methods to obtain the solid-solid transition temperature of Etiracetam system, showing two enantiotropically related polymorphs. → The first method, based on a thermodynamic development, is sensitive to the correctness of the data required. → The second method is an experimental study of the stability thermal range of each morph. → We identify the nature of crystals in suspension at equilibrium through Raman analysis. → The solid-solid transition temperature is found equal to 303.65 K ± 0.5 K. - Abstract: This paper presents two distinct methods for the determination of the solid-solid transition temperature (T tr ) separating the temperature ranges of stability of two crystallographic forms, hereafter called morphs, of a same substance. The first method, based on thermodynamic calculations, consists in determining T tr as the temperature at which the Gibbs free energies of the two morphs are equal to each other. For this purpose, some thermodynamic characteristics of both morphs are required, such as the specific heat capacities, the melting temperatures and the melting enthalpies. These are obtained using the Differential Scanning Calorimetry (DSC). In the second method, T tr is determined directly by an experimental study of the temperature ranges of stability of each morph. The three main originalities of the method developed are (i) to prepare samples composed by an isomassic mixture of crystals of both morphs, (ii) to set them in a thermostated and agitated suspension, and (iii) to use an in situ Raman spectroscopic probe for the determination of the crystallographic form of the crystals in suspension at equilibrium. Both methods are applied to determine the solid-solid transition temperature of the enantiotropic system of Etiracetam, and both of its two crystallographic forms so far identified, named morph I and morph II. The first method is shown to be very sensitive to the experimental data obtained by DSC
Ultralow Friction Self-Lubricating Nanocomposites with Mesoporous Metal-Organic Frameworks as Smart Nanocontainers for Lubricants.

Science.gov (United States)

Zhang, Guoliang; Xie, Guoxin; Si, Lina; Wen, Shizhu; Guo, Dan

2017-11-01

Smart nanocontainers with stimuli-responsive property can be used to fabricate a new kind of self-lubricating nanocomposite, while the practical potential of the metal-organic frameworks (MOFs) as nanocontainers for lubricants has not been realized. In this work, mesoporous Cu-BTC MOFs storing oleylamine nanocomposites were explored from synthesis and microstructure to self-lubricating characterization. The stress stimuli-responsiveness behavior of the Cu-BTC storing oleylamine (Cu-BTCO) for lubrication has been investigated by subjecting it to macroscopic ball-on-disc friction tests. The steady-state coefficients of friction (COFs) of the Cu-BTC nanocomposites without lubricants were ca. 0.5. In contrast, after oleylamine as the lubricant was incorporated into the Cu-BTC container in the nanocomposite, ultralow friction (COF, ca. 0.03) was achieved. It has been demonstrated that the improved lubricating performance was associated with the lubricating film which was in situ produced by the chemical reaction between the oleylamine released from the nanocontainer and the friction pairs. Therefore, the nanocomposite with smart Cu-BTC container holds the promise of realizing extraordinary self-lubricating properties under stress stimuli.

Experiments on Ultrasonic Lubrication Using a Piezoelectrically-assisted Tribometer and Optical Profilometer.

Science.gov (United States)

Dong, Sheng; Dapino, Marcelo

2015-09-28

Friction and wear are detrimental to engineered systems. Ultrasonic lubrication is achieved when the interface between two sliding surfaces is vibrated at a frequency above the acoustic range (20 kHz). As a solid-state technology, ultrasonic lubrication can be used where conventional lubricants are unfeasible or undesirable. Further, ultrasonic lubrication allows for electrical modulation of the effective friction coefficient between two sliding surfaces. This property enables adaptive systems that modify their frictional state and associated dynamic response as the operating conditions change. Surface wear can also be reduced through ultrasonic lubrication. We developed a protocol to investigate the dependence of friction force reduction and wear reduction on the linear sliding velocity between ultrasonically lubricated surfaces. A pin-on-disc tribometer was built which differs from commercial units in that a piezoelectric stack is used to vibrate the pin at 22 kHz normal to the rotating disc surface. Friction and wear metrics including effective friction force, volume loss, and surface roughness are measured without and with ultrasonic vibrations at a constant pressure of 1 to 4 MPa and three different sliding velocities: 20.3, 40.6, and 87 mm/sec. An optical profilometer is utilized to characterize the wear surfaces. The effective friction force is reduced by 62% at 20.3 mm/sec. Consistently with existing theories for ultrasonic lubrication, the percent reduction in friction force diminishes with increasing speed, down to 29% friction force reduction at 87 mm/sec. Wear reduction remains essentially constant (49%) at the three speeds considered.
Thermal Stability and Lubrication Properties of Biodegradable Castor Oil on AISI 4140 Steel

Directory of Open Access Journals (Sweden)

María Teresa Hernández-Sierra

2018-06-01

Full Text Available Lubricants have much importance in several industries, principally serving to reduce friction and wear in mechanical elements. In this study, the influence of Castor oil as bio-lubricant on the friction and wear performance of AISI 4140 steel was investigated. For that purpose, pin-on-disk friction tests were conducted according to ASTM G-99, by using pins of tungsten carbide (WC as counterparts. The experiments were performed at two different temperatures. This work also presents the Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (ATR-FTIR and 1H-NMR analyses for the chemical characterization of oils and a study of their degradation by oxidation. The analysis of the damage caused to steel due to friction was deepened by analyzing its microhardness and microstructure in the worn zone. As a reference, the same experiments were performed with a commercial oil. The friction behavior of 4140 steel/WC with Castor oil lubrication at the two temperatures was notably better than that obtained under the reference oil lubrication. The kinetic friction coefficient (µk was up to 76% lower. However, a slight increase in steel wear was observed under Castor oil lubrication. Despite this, these results suggest that Castor oil could be used as bio-lubricant in systems which are susceptible to levels of high friction.
Plasmaspuiten van zelfsmerende deklagen met vaste smeermiddelen

OpenAIRE

Vos, Frans

1999-01-01

The development of 'plasma sprayed self-lubricating coatings with solid lubricants' is an answer to industry's increasing demand for alternatives to oil lubricated systems. Solid lubricants offer an improved high temperature and low pressure resistance and an immediate performance after a long out-of-service period. A homogeneous dispersion of solid lubricant particles in a wear resistant material guarantees a long-term service of the lubricated component due to a continuous release of the lu...
Coefficient of friction of a starved lubricated spur gear pair

International Nuclear Information System (INIS)

Liu, Huaiju; Zhu, Caichao; Sun, Zhangdong; Zhang, Yuanyuan; Song, Chaosheng

2016-01-01

The frictional power loss issue of gear pairs becomes an important concern in both industry and academia due to the requirement of the energy saving and the improvement of power density of gear drives. A thermal starved elastohydrodynamic lubrication model is developed to study the tribological performance of a spur gear pair under starved lubrication conditions. The contact pressure, the film thickness, the temperature rise, the frictional power loss, as well as the coefficient of friction are evaluated by considering the variation of the curvature radius, the sliding/rolling motion, and the load distribution of gear tooth within the meshing period. Effects of lubrication starvation condition, load and speed on the coefficient of friction are studied.
Effect of solid lubricants on friction and wear behaviour of alloyed ...

Indian Academy of Sciences (India)

Friction and wear behaviour of MoS2, boric acid, graphite and TiO2 at four different sliding speeds (1.0, 1.5, 2.0, 2.5 m/s) has been compared with dry sliding condition. MoS2 and graphite show 30 to 50% reduction in mass loss compared to other lubricants at all sliding speeds. Friction coefﬁcient reduces with increase in ...
Practical lubrication for industrial facilities

CERN Document Server

Bloch, Heinz

2016-01-01

Now completely revised and updated, this definitive, hands-on reference provides a comprehensive resource on the fundamental principles of lubricant application, what products are available, and which lubricants are most effective for specific applications. It also offers a detailed and highly practical discussion of lubrication delivery systems. You'll gain a clearer understanding of the "why" of relevant industrial lubrication practices, and, importantly, how these practices will facilitate optimized results. Lubricant applications covered include bearings and machine elements in earthbound
The State of the Art in Cold Forging Lubrication

DEFF Research Database (Denmark)

Bay, Niels

1994-01-01

The manufature of components in steel, aluminium and copper alloys by cold forging production has increased ever since the 1950's. Typical processes are forward rod extrusion and backward can extrusion, upsetting, ironing, tube extrusion and radial extrusion. The tribological conditions in cold...... forging are extremely severe due to large surface expansion and normal pressure in the tool/workpiece interface combined with elevated tool temperatures. Except for the more simple cold forging operations successful production therefore requires advanced lubrication systems. The present paper gives...... a detailed description of the state of art for lubricant systems for cold forging of C-steels and low alloy steels as well as aluminium alloys including all the basic operations such as cleaning of the slugs, application of eventual conversion coating and lubrication. As regards cold forging of steel...
Lubrication and cartilage.

Science.gov (United States)

Wright, V; Dowson, D

1976-02-01

Mechanisms of lubrication of human synovial joints have been analysed in terms of the operating conditions of the joint, the synovial fluid and articular cartilage. In the hip and knee during a walking cycle the load may rise up to four times body weight. In the knee on dropping one metre the load may go up to 25 time body weight. The elastic modulus of cartilage is similar to that of the synthetic rubber of a car tyre. The cartilage surface is rough and in elderly specimens the centre line average is 2-75 mum. The friction force generated in reciprocating tests shows that both cartilage and synovial fluid are important in lubrication. The viscosity-shear rate relationships of normal synovial fluid show that it is non-Newtonian. Osteoarthrosic fluid is less so and rheumatoid fluid is more nearly Newtonian. Experiments with hip joints in a pendulum machine show that fluid film lubrication obtains at some phases of joint action. Boundary lubrication prevails under certain conditions and has been examined with a reciprocating friction machine. Digestion of hyaluronate does not alter the boundary lubrication, but trypsin digestion does. Surface active substances (lauryl sulphate and cetyl 3-ammonium bromide) give a lubricating ability similar to that of synovial fluid. The effectiveness of the two substances varies with pH.
Slippery self-lubricating polymer surfaces

Science.gov (United States)

Aizenberg, Joanna; Aizenberg, Michael; Cui, Jiaxi; Dunn, Stuart; Hatton, Benjamin; Howell, Caitlin; Kim, Philseok; Wong, Tak Sing; Yao, Xi

2018-05-08

The present disclosure describes a strategy to create self-healing, slippery self-lubricating polymers. Lubricating liquids with affinities to polymers can be utilized to get absorbed within the polymer and form a lubricant layer (of the lubricating liquid) on the polymer. The lubricant layer can repel a wide range of materials, including simple and complex fluids (water, hydrocarbons, crude oil and bodily fluids), restore liquid-repellency after physical damage, and resist ice, microorganisms and insects adhesion. Some exemplary applications where self-lubricating polymers will be useful include energy-efficient, friction-reduction fluid handling and transportation, medical devices, anti-icing, optical sensing, and as self-cleaning, and anti-fouling materials operating in extreme environments.
Safety characteristics of hydrogen at super ambient conditions: lubricant contamination influencing the auto ignition temperature

International Nuclear Information System (INIS)

Liebner, C.; Schroder, V.; Holtappels, K.

2006-01-01

Inventing hydrogen as a commonly used future energy carrier the long term social acceptance as well as the clean energy image strongly depends upon the safety of its applications. The safety characteristics of hydrogen build a special challenge e.g. in the field of combustion engine development. Small impurities from lubricants used in motors and pumps, may serve as radical source, strongly influencing the auto ignition temperature of hydrogen. Auto Ignition Temperature (AIT) of Hydrogen-Air mixtures were measured in closed autoclaves made from stainless steel, similar to the closed bomb method described in the European standard EN 1839. Initial pressures of 10 bar(a) and 30 bar(a) of a premixed stoichiometric hydrogen-air mixture were investigated. Auto ignition can be obtained about 100 K below the standard AIT (560 deg C, atmospheric pressure) and 300 K below the standard AIT when contaminated through motor oil. (authors)
Reliability model for helicopter main gearbox lubrication system using influence diagrams

International Nuclear Information System (INIS)

Rashid, H.S.J.; Place, C.S.; Mba, D.; Keong, R.L.C.; Healey, A.; Kleine-Beek, W.; Romano, M.

2015-01-01

The loss of oil from a helicopter main gearbox (MGB) leads to increased friction between components, a rise in component surface temperatures, and subsequent mechanical failure of gearbox components. A number of significant helicopter accidents have been caused due to such loss of lubrication. This paper presents a model to assess the reliability of helicopter MGB lubricating systems. Safety risk modeling was conducted for MGB oil system related accidents in order to analyse key failure mechanisms and the contributory factors. Thus, the dominant failure modes for lubrication systems and key contributing components were identified. The Influence Diagram (ID) approach was then employed to investigate reliability issues of the MGB lubrication systems at the level of primary causal factors, thus systematically investigating a complex context of events, conditions, and influences that are direct triggers of the helicopter MGB lubrication system failures. The interrelationships between MGB lubrication system failure types were thus identified, and the influence of each of these factors on the overall MGB lubrication system reliability was assessed. This paper highlights parts of the HELMGOP project, sponsored by the European Aviation Safety Agency to improve helicopter main gearbox reliability. - Highlights: • We investigated methods to optimize helicopter MGB oil system run-dry capability. • Used Influence Diagram to assess design and maintenance factors of MGB oil system. • Factors influencing overall MGB lubrication system reliability were identified. • This globally influences current and future helicopter MGB designs
A new Friction and Lubrication Test for Cold Forging

DEFF Research Database (Denmark)

Bay, Niels; Wibom, Ole; Aalborg Nielsen, J

1995-01-01

This paper presents a new friction and lubrication test for cold forging. The test allows controlled variation of the surface expansion in the range 0-2000%, the tool temperature in the range 20-270°C and the sliding length between 0 and infinite. Friction is decreasing with increasing temperature...
Hairy polyelectrolyte brushes-grafted thermosensitive microgels as artificial synovial fluid for simultaneous biomimetic lubrication and arthritis treatment.

Science.gov (United States)

Liu, Guoqiang; Liu, Zhilu; Li, Na; Wang, Xiaolong; Zhou, Feng; Liu, Weimin

2014-11-26

We report the fabrication of poly(3-sulfopropyl methacrylate potassium salt) (PSPMK) brushes grafted poly(N-isopropylacrylamide) (PNIPAAm) microgels and their potential as artificial synovial fluid for biomimetic aqueous lubrication and arthritis treatment. The negatively charged PSPMK brushes and thermosensitive PNIPAAm microgels play water-based hydration lubrication and temperature-triggered drug release, respectively. Under soft friction pairs, an ultralow coefficient of friction was achieved, while the hairy thermosensitive microgels showed a desirable temperature-triggered drugs release performance. Such a soft charged hairy microgel offers great possibility for designing intelligent synovial fluid. What is more, the combination of lubrication and drug loading capabilities enables the large clinical potential of novel soft hairy nanoparticles as synthetic joint lubricant fluid in arthritis treatment.
Characteristics Study of In-Situ Capacitive Sensor for Monitoring Lubrication Oil Debris.

Science.gov (United States)

Han, Zhibin; Wang, Yishou; Qing, Xinlin

2017-12-08

As an essential part of engine health monitoring (EHM), online lubrication oil debris monitoring has recently received great attention for the assessment of rotating and reciprocating parts in aero-engines, due to its high integration, low cost and safe characteristics. However, it is be a challenge to find a suitable sensor operating in such a complex environment. We present an unconventional novel approach, in which a cylinder capacitive sensor is designed and integrated with the pipeline of an engine lubrication system, so that the capacitive sensor can effectively detect changes in the lubrication oil condition. In this paper, an attempt to illustrate the performance characteristics of the developed cylinder capacitive sensor is made, through an experiment system that simulates a real scenario of a lubrication oil system. The main aim of the research was to qualitatively describe the relationship between the sensor parameter and the lubrication oil debris. In addition, the effect of the temperature and flow rate of the lubrication oil on capacitance change was performed by several experiments and we figured out a compensation method. The experimental results demonstrated that the cylinder capacitive sensor can potentially be used for lubrication oil debris monitoring of the health condition of an aero-engine.
Unctuous ZrO2 nanoparticles with improved functional attributes as lubricant additives

Science.gov (United States)

Espina Casado, Jorge; Fernández González, Alfonso; José del Reguero Huerga, Ángel; Rodríguez-Solla, Humberto; Díaz-García, Marta Elena; Badía-Laíño, Rosana

2017-12-01

One of the main drawbacks in the application of metal-oxide nanoparticles as lubricant additives is their poor stability in organic media, despite the good anti-wear, friction-reducing and high-load capacity properties described for these materials. In this work, we present a novel procedure to chemically cap the surface of ZrO2 nanoparticles (ZrO2NPs) with long hydrocarbon chains in order to obtain stable dispersions of ZrO2NPs in non-aqueous media without disrupting their attributes as lubricant additives. C-8, C-10 and C-16 saturated flexible chains were attached to the ZrO2NP surface and their physical and chemical characterization was performed by transmission electron microscopy, thermogravimetric analysis, attenuated total reflectance Fourier transform infrared spectroscopy, x-ray photoelectron spectroscopy and solid-state nuclear magnetic resonance. The dispersion stability of the modified ZrO2NPs in non-aqueous media was studied using static multiple light scattering. Tribological tests demonstrated that dispersions of the long-chain capped ZrO2NPs in base lubricating oils exhibited low friction coefficients and improved the anti-wear properties of the base oil when compared with the raw lubricating oil.
Making Self-Lubricating Parts By Powder Metallurgy

Science.gov (United States)

Sliney, Harold E.; Dellacorte, Christopher

1990-01-01

Compositions and parameters of powder-metallurgical fabrication processes determined for new class of low-friction, low-wear, self-lubricating materials. Used in oxidizing or reducing atmospheres in bearings and seals, at temperatures from below 25 degrees C to as high as 900 degrees C. Thick parts made with minimal waste.
Lubrication method and apparatus

Energy Technology Data Exchange (ETDEWEB)

McCarty, R.S.

1988-05-03

In a combustion turbine engine comprising a bearing member journaling a rotatable component, and compressor means providing pressurized air, the method of providing liquid lubricant to the bearing member is described comprising the steps of: providing the liquid lubricant sealed within a collapsible and penetrable bladder member; enclosing the bladder member and lubricant within a substantially closed housing sealingly cooperating with the bladder member to define a pair of chambers; arranging a penetrating lance member in one of the pair of chambers in confronting relationship with the bladder member; providing communication of the pressurized air with the other of the pair of chambers to force the bladder member into impaled sealing relationship with the lance member; communicating the lubricant to the bearing member via the lance member; and utilizing the pressurized air within the other chamber to collapse the bladder member, simultaneously flowing the lubricant to the bearing member.
Surface functionalization by fine ultraviolet-patterning of nanometer-thick liquid lubricant films

International Nuclear Information System (INIS)

Lu, Renguo; Zhang, Hedong; Komada, Suguru; Mitsuya, Yasunaga; Fukuzawa, Kenji; Itoh, Shintaro

2014-01-01

Highlights: • We present fine UV-patterning of nm-thick liquid films for surface functionalization. • The patterned films exhibit both a morphological pattern and a functional pattern of different surface properties. • The finest pattern linewidth was 0.5 μm. • Fine patterning is crucial for improving surface and tribological properties. - Abstract: For micro/nanoscale devices, surface functionalization is essential to achieve function and performance superior to those that originate from the inherent bulk material properties. As a method of surface functionalization, we dip-coated nanometer-thick liquid lubricant films onto solid surfaces and then patterned the lubricant films with ultraviolet (UV) irradiation through a photomask. Surface topography, adhesion, and friction measurements demonstrated that the patterned films feature a concave–convex thickness distribution with thicker lubricant in the irradiated regions and a functional distribution with lower adhesion and friction in the irradiated convex regions. The pattern linewidth ranged from 100 to as fine as 0.5 μm. The surface functionalization effect of UV-patterning was investigated by measuring the water contact angles, surface energies, friction forces, and depletion of the patterned, as-dipped, and full UV-irradiated lubricant films. The full UV-irradiated lubricant film was hydrophobic with a water contact angle of 102.1°, and had lower surface energy, friction, and depletion than the as-dipped film, which was hydrophilic with a water contact angle of 80.7°. This demonstrates that UV irradiation substantially improves the surface and tribological properties of the nanometer-thick liquid lubricant films. The UV-patterned lubricant films exhibited superior surface and tribological properties than the as-dipped film. The water contact angle increased and the surface energy, friction, and depletion decreased as the pattern linewidth decreased. In particular, the 0.5-μm patterned lubricant
Microstructural modelling and lubrication study during zirconium alloy hot extrusion

International Nuclear Information System (INIS)

Gaudout, B.

2009-01-01

Using torsion tests (with strain rate jumps) and an experimental hot mini-extrusion apparatus, several samples zirconium alloy have been deformed: Zircaloy-4 (high α range) and Zr-1Nb (α + β domain). The fragmentation of the microstructure and post-dynamic grain growth have been examined. The main difference between these two alloys is that Zr-1Nb does not show grain growth during a heat treatment within the α + β domain after hot deformation. The recrystallization volume fraction has been measured on extruded samples with or without heat treatment. These rheological and microstructural data have been used to determine the parameters of a microstructural model including: a work-hardening model (Laaasraoui/Jonas), a continuous dynamic recrystallization model (Gourdet/Montheillet) and a grain growth model. This model leads to a good prediction of recrystallization volume fraction for Zircaloy-4 extrusion. However, the Zr-1Nb model cannot be validated because of the difficulty to observe deformed microstructures. Extrusion process is lubricated with a solid film. Trapping tests show that this lubricant is thermoviscoplastic. Friction along the container and several observations show the lubrication is not realized by a continuous film. Indeed, the heterogeneousness of deformation of these alloys causes a rupture of the lubricant film. Experiments and numerical simulations show that the radial gradient of axial displacement is affected by friction but also by stress softening of the alloys. (author)
The effect of cryogenic cooling and minimum quantity lubrication on end milling of titanium alloy Ti-6Al-4V

Energy Technology Data Exchange (ETDEWEB)

Park, Kyung Hee; Yang, Gi Dong; Lee, Dong Yoon; Kim, Tae Gon; Lee, Seok Woo [Korea Institute of Industrial Technology, Cheonan (Korea, Republic of); Suhaimi, M. A. [Universiti Teknologi Malaysia, Johor Bahru (Malaysia); Kim, Dong Won [Chonbuk National University, Jeonju (Korea, Republic of)

2015-11-15

The cooling down of cutting temperature in machining is very important for the improvement of tool life, especially when dealing with work materials that have low thermal conductivity such as titanium alloy. In this study designed to investigate the machining performance of a variety of cooling methods, cryogenic, Minimum quantity lubrication (MQL), and flood cooling are performed on solid end milling of titanium alloy, Ti-6Al-4V. In particular, the effect of internal and external spray methods on cryogenic machining is analyzed with a specially designed liquid nitrogen spraying system by evaluating tool wear and cutting force at cutting conditions. The cutting force is also analyzed for tool breakage detection. As a result, the combination of MQL and internal cryogenic cooling improves tool life by up to 32% compared to conventional cooling methods. The cutting force is also reduced significantly by this combination of cooling and lubrication strategy of side end milling.

The effect of cryogenic cooling and minimum quantity lubrication on end milling of titanium alloy Ti-6Al-4V

International Nuclear Information System (INIS)

Park, Kyung Hee; Yang, Gi Dong; Lee, Dong Yoon; Kim, Tae Gon; Lee, Seok Woo; Suhaimi, M. A.; Kim, Dong Won

2015-01-01

The cooling down of cutting temperature in machining is very important for the improvement of tool life, especially when dealing with work materials that have low thermal conductivity such as titanium alloy. In this study designed to investigate the machining performance of a variety of cooling methods, cryogenic, Minimum quantity lubrication (MQL), and flood cooling are performed on solid end milling of titanium alloy, Ti-6Al-4V. In particular, the effect of internal and external spray methods on cryogenic machining is analyzed with a specially designed liquid nitrogen spraying system by evaluating tool wear and cutting force at cutting conditions. The cutting force is also analyzed for tool breakage detection. As a result, the combination of MQL and internal cryogenic cooling improves tool life by up to 32% compared to conventional cooling methods. The cutting force is also reduced significantly by this combination of cooling and lubrication strategy of side end milling.
Distilling solid carbonaceous materials

Energy Technology Data Exchange (ETDEWEB)

Nielsen, H; Laing, B

1926-12-04

In the distillation of solid carbonaceous materials with by-product recovery by direct heating with a gas such as water gas, producer gas, or combustion gas which is passed in counter-flow to the materials, the volume of the gas used is such as to lower the vapor tension of the volatiles to enable the oil vapor to be liberated at temperatures not exceeding 450 to 500/sup 0/C and so that the gaseous mixture may be cooled to from 80 to 100/sup 0/C without causing the highest boiling oil fraction to condense. Coking coals may be subjected to a preliminary heat treatment with gases containing an oxygen content of from 2 to 8 percent to reduce their coking properties, and oxygen may be added to the heating gases to assist the polymerization of resinous bodies. Lubricating oil may be obtained by treating the primary oil with caustic soda to remove tar acids, refining the residue with sulfuric acid, distilling off 25 percent of the refined oil and passing the remainder through a filter press at -5/sup 0/C to extract the paraffin wax. The residue of wax-free oil is distilled to yield a lubricating oil which at normal temperatures has a static coefficient of friction of from .1 to .185. Other specifications are referred to.
Experience with synthetic fluorinated fluid lubricants

Science.gov (United States)

Conley, Peter L.; Bohner, John J.

1990-01-01

Since the late 1970's, the wet lubricant of choice for space mechanisms has been one of the family of synthetic perfluoro polyalkylether (PFPE) compounds, namely Fomblin Z-25 (Bray-815Z) or DuPont's Krytox 143xx series. While offering the advantages of extremely low vapor pressures and wide temperature ranges, these oils and derived greases have a complex chemistry compared to the more familiar natural and synthetic hydrocarbons. Many aerospace companies have conducted test programs to characterize the behavior of these compounds in a space environment, resulting in a large body of hard knowledge as well as considerable space lore concerning the suitability of the lubricants for particular applications and techniques for successful application. The facts are summarized and a few myths about the compounds are dispelled, and some performance guidelines for the mechanism design engineer are provided.
Identification of tribological research and development needs for lubrication of advanced heat engines

Energy Technology Data Exchange (ETDEWEB)

Fehrenbacher, L.L.; Levinson, T.M.

1985-09-01

The continuous evolution of higher power density propulsion systems has always fueled the search for materials and lubricants with improved thermal and/or durability characteristics. Tribology of the upper cylinder region is the major technology roadblock in the path of the adiabatic diesel engine which has an energy reduction potential that exceeds that of all other engine development types. This tribology assessment resulted in the following major conclusions: a low friction and a low wear seal between the ring belt and cylinder bore are the most critical tribology functions in the diesel combustion chamber; development of solid lubrication systems will not satisfy the simultaneous low friction and low wear requirements in the upper cylinder area; development of separate upper cylinder liquid lubrication systems offers the most attractive design alternative for meeting the operational goals of future ''minimum cooled'' diesel engines.
Testing of nuclear grade lubricants and their effects on A540 B24 and A193 B7 bolting materials

International Nuclear Information System (INIS)

Czajkowski, C.J.

1985-01-01

An investigation was performed on eleven commonly used lubricants by the nuclear power industry. The investigation included EDS analysis of the lubricants, notched-tensile constant extension rate testing of bolting materials with the lubricants, frictional testing of the lubricants and weight loss testing of a bonded solid film lubricant. The report generally concludes that there is a significant amount of variance in the mechanical properties of common bolting materials; that MoS 2 can hydrolyze to form H 2 S at 100 0 C and cause stress corrosion cracking (SCC) of bolting materials, and that the use of copper-containing lubricants can be potentially detrimental to high strength steels in an aqueous environment. Additionally, the testing of various lubricants disclosed that some lubricants contain potentially detrimental elements (e.g. S, Sb) which can promote SCC of the common bolting materials. One of the most significant findings of this report is the observation that both A193 B7 and A540 B24 bolting materials are susceptible to transgranular stress corrosion cracking in demineralized H 2 O at 280 0 C in notched tensile tests
Microstructure and wear behaviors of laser clad NiCr/Cr3C2-WS2 high temperature self-lubricating wear-resistant composite coating

Science.gov (United States)

Yang, Mao-Sheng; Liu, Xiu-Bo; Fan, Ji-Wei; He, Xiang-Ming; Shi, Shi-Hong; Fu, Ge-Yan; Wang, Ming-Di; Chen, Shu-Fa

2012-02-01

The high temperature self-lubricating wear-resistant NiCr/Cr3C2-30%WS2 coating and wear-resistant NiCr/Cr3C2 coating were fabricated on 0Cr18Ni9 austenitic stainless steel by laser cladding. Phase constitutions and microstructures were investigated, and the tribological properties were evaluated using a ball-on-disc wear tester under dry sliding condition at room-temperature (17 °C), 300 °C and 600 °C, respectively. Results indicated that the laser clad NiCr/Cr3C2 coating consisted of Cr7C3 primary phase and γ-(Fe,Ni)/Cr7C3 eutectic colony, while the coating added with WS2 was mainly composed of Cr7C3 and (Cr,W)C carbides, with the lubricating WS2 and CrS sulfides as the minor phases. The wear tests showed that the friction coefficients of two coatings both decrease with the increasing temperature, while the both wear rates increase. The friction coefficient of laser clad NiCr/Cr3C2-30%WS2 is lower than the coating without WS2 whatever at room-temperature, 300 °C, 600 °C, but its wear rate is only lower at 300 °C. It is considered that the laser clad NiCr/Cr3C2-30%WS2 composite coating has good combination of anti-wear and friction-reducing capabilities at room-temperature up to 300 °C.
Monitoring the viscosity of diesel engine lubricating oil by using acoustic emission technique, the selection of measurement parameters

International Nuclear Information System (INIS)

Othman Inayatullah; Nordin Jamaludin; Fauziah Mat

2009-04-01

Acoustic emission technique has been developed through years of monitoring and diagnosis of bearing, but it is still new in the diagnosis and monitoring of lubrication oil to bearings drive. The propagation of acoustic emission signal is generated when the signal piston on the cylinder liner lubricating oil which is a par. The signal is analyzed in time domain to obtain the parameters of root mean squared, amplitude, energy and courtesy. Lubricant viscosity will undergo changes due to temperature, pressure and useful. This study focuses on the appropriate parameters for the diagnosis and monitoring of lubricating oil viscosity. Studies were conducted at a constant rotational speed and temperature, but use a different age. The results showed that the energy parameter is the best parameter used in this monitoring. However, this parameter cannot be used directly and it should be analyzed using mathematical formulas. This mathematical formula is a relationship between acoustic emission energy with the viscosity of lubricating oil. (author)
Determining an Efficient Solvent Extraction Parameters for Re-Refining of Waste Lubricating Oils

Directory of Open Access Journals (Sweden)

Hassan Ali Durrani

2012-04-01

Full Text Available Re-refining of vehicle waste lubricating oil by solvent extraction is one of the efficient and cheapest methods. Three extracting solvents MEK (Methyl-Ethyl-Ketone, 1-butanol, 2-propanol were determined experimentally for their performance based on the parameters i.e. solvent type, solvent oil ratio and extraction temperature. From the experimental results it was observed the MEK performance was highest based on the lowest oil percent losses and highest sludge removal. Further, when temperature of extraction increased the oil losses percent also decreased. This is due to the solvent ability that dissolves the base oil in waste lubricating oil and determines the best SOR (Solvent Oil Ratio and extraction temperatures.
Molecular simulations of hydrocarbon lubricants: Impact of molecular architecture on performance properties

Science.gov (United States)

Kioupis, Loukas I.

2000-07-01

With the increased power of modern computers, molecular modeling has been used widely and proven to be a valuable tool for elucidating the physical processes important in many industrial and engineering problems. Of particular interest to us is the rheology and physical chemistry of complex fluids, such as hydrocarbon lubricants and polymers. The goal is to provide qualitative and quantitative molecular-level explanations for the behavior of such fluids, and provide guidance in the development of new improved materials. For example, during the production of poly-α-olefin (PAO) synthetic lubricants, the number of the isomer skeletal structures that can be obtained is staggering. Which of the countless PAO isomers produce a lubricant with superior performance properties? How does it behave under different operational conditions of temperature, pressure, and shear rate? A fundamental understanding of the effect that molecular structure has on the oil's rheological and lubricant performance is first needed, in order to answer these questions. To serve this purpose, we have developed efficient molecular dynamics (MD) simulation programs, which utilize multiple time step algorithms and parallel computational techniques. This enables us to conduct simulations of typical PAO isomers and compute the viscosity, as well as several other dynamic and static properties, as a function of temperature, pressure, and shear rate. The key molecular mechanisms that determine important macroscopic properties, such as viscosity index, viscosity-pressure coefficient, traction coefficient, and shear thinning behavior are discussed. Based on this analysis, lubricant and traction fluid structures that have a high likelihood of having desirable properties are proposed. In addition, studies on simple alkane mixtures are presented, in an attempt to understand the more complex polydisperse lubricant fluids, their blends, and their interaction with additives.
Development and characterization of laser clad high temperature self-lubricating wear resistant composite coatings on Ti–6Al–4V alloy

International Nuclear Information System (INIS)

Liu, Xiu-Bo; Meng, Xiang-Jun; Liu, Hai-Qing; Shi, Gao-Lian; Wu, Shao-Hua; Sun, Cheng-Feng; Wang, Ming-Di; Qi, Long-Hao

2014-01-01

Highlights: • A novel high temperature self-lubricating anti-wear composite coating was fabricated. • Reinforced carbides as well as self-lubricating sulfides were in situ synthesized. • Microhardness of the Ti–6Al–4V substrate was significantly improved. • Friction coefficient and wear rate of the composite coating were greatly reduced. - Abstract: To enhance the wear resistance and friction-reducing capability of titanium alloy, a process of laser cladding γ-NiCrAlTi/TiC + TiWC 2 /CrS + Ti 2 CS coatings on Ti–6Al–4V alloy substrate with preplaced NiCr/Cr 3 C 2 –WS 2 mixed powders was studied. A novel coating without cracks and few pores was obtained in a proper laser processing. The composition and microstructure of the fabricated coating were examined by X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) techniques, and tribological properties were evaluated using a ball-on-disc tribometer under dry sliding wear test conditions at 20 °C (room-temperature), 300 °C, 600 °C, respectively. The results show that the coating has unique microstructure consisting of α-Ti, TiC, TiWC 2 , γ-NiCrAlTi, Ti 2 CS and CrS phases. Average microhardness of the composite coating is 1005 HV 0.2 , which is about 3-factor higher than that of Ti–6Al–4V substrate (360 HV 0.2 ). The friction coefficient and wear rate of the coating are greatly decreased due to the combined effects of the dominating anti-wear capabilities of reinforced TiC and TiWC 2 carbides and the CrS and Ti 2 CS sulfides which have excellent self-lubricating property
Biodegradation of lubricant oil

African Journals Online (AJOL)

M

2012-09-25

Sep 25, 2012 ... lubricating oil, showed high biodegradation efficiency for different used lubricating oils. Capability of ..... amount after biodegradation showed no difference in the .... products polluted sites in Elele, Rivers State, Ngeria.
Elastic model of the traction behavior of two traction lubricants

Science.gov (United States)

Loewenthal, S. H.; Rohn, D. A.

1984-01-01

In the analysis of rolling-sliding concentrated contacts, such as gears, bearings and traction drives, the traction characteristics of the lubricant are of prime importance. The elastic shear modulus and limiting shear stress properties of the lubricant dictate the traction/slip characteristics and power loss associated with an EHD contact undergoing slip and/or spin. These properties can be deducted directly from the initial slope m and maximum traction coefficient micron of an experimental traction curve. In this investigation, correlation equations are presented to predict m and micron for two modern traction fluids based on the regression analysis of 334 separate traction disk machine experiments. The effects of contact pressure, temperature, surface velocity, ellipticity ratio are examined. Problems in deducing lubricant shear moduli from disk machine tests are discussed. Previously announced in STAR as N83-20116
Vapor-solid-solid grown Ge nanowires at integrated circuit compatible temperature by molecular beam epitaxy

Science.gov (United States)

Zhu, Zhongyunshen; Song, Yuxin; Zhang, Zhenpu; Sun, Hao; Han, Yi; Li, Yaoyao; Zhang, Liyao; Xue, Zhongying; Di, Zengfeng; Wang, Shumin

2017-09-01

We demonstrate Au-assisted vapor-solid-solid (VSS) growth of Ge nanowires (NWs) by molecular beam epitaxy at the substrate temperature of ˜180 °C, which is compatible with the temperature window for Si-based integrated circuit. Low temperature grown Ge NWs hold a smaller size, similar uniformity, and better fit with Au tips in diameter, in contrast to Ge NWs grown at around or above the eutectic temperature of Au-Ge alloy in the vapor-liquid-solid (VLS) growth. Six ⟨110⟩ growth orientations were observed on Ge (110) by the VSS growth at ˜180 °C, differing from only one vertical growth direction of Ge NWs by the VLS growth at a high temperature. The evolution of NWs dimension and morphology from the VLS growth to the VSS growth is qualitatively explained by analyzing the mechanism of the two growth modes.
Development of lubricant test for punching and blanking

DEFF Research Database (Denmark)

Olsson, David Dam

2001-01-01

The background for development of new lubricants Requirements to lubricant test for punching Methods of evaluating lubricants Test equipment developed at DTU Conclusion.......The background for development of new lubricants Requirements to lubricant test for punching Methods of evaluating lubricants Test equipment developed at DTU Conclusion....
Direct verification of the lubrication force on a sphere travelling through a viscous film upon approach to a solid wall

KAUST Repository

Marston, Jeremy; Wang, Yong; Thoroddsen, Sigurdur T

2010-01-01

on the sphere, derived from lubrication theory. Using high-speed video imaging we show, for the first time, that the equations of motion based on the lubrication approximation correctly describe the deceleration of the sphere when St < Stc. Furthermore, we
Power system with an integrated lubrication circuit

Science.gov (United States)

Hoff, Brian D [East Peoria, IL; Akasam, Sivaprasad [Peoria, IL; Algrain, Marcelo C [Peoria, IL; Johnson, Kris W [Washington, IL; Lane, William H [Chillicothe, IL

2009-11-10

A power system includes an engine having a first lubrication circuit and at least one auxiliary power unit having a second lubrication circuit. The first lubrication circuit is in fluid communication with the second lubrication circuit.
Design and application on experimental platform for high-speed bearing with grease lubrication

Directory of Open Access Journals (Sweden)

He Qiang

2015-12-01

Full Text Available The experimental platform for high-speed grease is an important tool for research and development of high-speed motorized spindle with grease lubrication. In this article, the experimental platform for high-speed grease is designed and manufactured which consists of the drive system, the test portion, the loading system, the lubrication system, the control system, and so on. In the meantime, the high-speed angular contact ceramic ball bearings B7005C/HQ1P4 as the research object are tested and contrasted in the grease lubrication and oil mist lubrication. The experimental platform performance is validated by contrast experiment, and the high-speed lubricated bearing performance is also studied especially in the relationship among the rotating speed,load and temperature rise. The results show that the experimental platform works steadily, accurate, and reliable in the experimental testing. And the grease lubrication ceramic ball bearings B7005C/HQ1P4 can be used in high-speed motorized spindle in the circular water cooling conditions when the rotating speed is lower than 40,000 r/min or the DN value (the value of the bearing diameter times the rotating speed is lower than the 1.44 × 106 mm r/min. Grease lubrication instead of oil mist lubrication under high-speed rotating will simplify the structure design of the high-speed motorized spindle and reduce the pollution to the environment.
Thermal Behavior of Aerospace Spur Gears in Normal and Loss-of-Lubrication Conditions

Science.gov (United States)

Handschuh, Robert F.

2015-01-01

Testing of instrumented spur gears operating at aerospace rotorcraft conditions was conducted. The instrumented gears were operated in a normal and in a loss-of-lubrication environment. Thermocouples were utilized to measure the temperature at various locations on the test gears and a test utilized a full-field, high-speed infrared thermal imaging system. Data from thermocouples was recorded during all testing at 1 hertz. One test had the gears shrouded and a second test was run without the shrouds to permit the infrared thermal imaging system to take data during loss-of-lubrication operation. Both tests using instrumented spur gears were run in normal and loss-of-lubrication conditions. Also the result from four other loss-of-lubrication tests will be presented. In these tests two different torque levels were used while operating at the same rotational speed (10000 revolutions per minute).
Evaluation of cermet materials suitable for lithium lubricated thrust bearings for high temperature operation

Science.gov (United States)

Sinclair, J. H.; Hendrixson, W. H.

1974-01-01

Cerment materials (HfC - 10 wt% W; HfC - 10 wt% TaC - 10 wt%W; HfC - 2 wt% CbC - 8 wt% Mo;Hfn - 10 wt% W; Hfn - 10 wt% TaN - 10 wt% W; and ZrC - 17 wt% W) were evaluated for possible use as lithium-lubricated bearings in the control system of a nuclear reactor. Tests of compatibility with lithium were made in T-111 (Ta-8W-2Hf) capsules at temperatures up to 1090 C. The tendencies of HfC-TaC-W, HfC-CbC-Mo, and HfN-W to bond to themselves and to the refractory alloys T-111 and TZM when enclosed in lithium-filled capsules under a pressure of 2000 psi at 980 and 1200 C for 1933 hours were evaluated. Thermal expansion characteristics were determined for the same three materials from room temperature to 1200 C. On the basis of these tests, HfC-10 TaC-10W and HfN-10W were selected as the best and second best candidates, respectively, of the materials tested for the bearing application.
Boundary lubrication of bearing steel in water-based lubricants with functional additives

NARCIS (Netherlands)

Wu, Y.

2017-01-01

This thesis focuses on the effect of additives on boundary lubrication of bearing steel for water-based lubrication systems. The oil-in-water (O/W) emulsion and the water-glycol based liquid were selected as the base fluids for research. Sulfur compounds, nitrogen heterocycles and graphene

Influence of Cooling Lubricants on the Surface Roughness and Energy Efficiency of the Cutting Machine Tools

Directory of Open Access Journals (Sweden)

Jersák J.

2017-08-01

Full Text Available The Technical University of Liberec and Brandenburg University of Technology Cottbus-Senftenberg investigated the influence of cooling lubricants on the surface roughness and energy efficiency of cutting machine tools. After summarizing the achieved experimental results, the authors conclude that cooling lubricants extensively influence the cutting temperature, cutting forces and energy consumption. Also, it is recognizable that cooling lubricants affect the cutting tools lifetime and the workpiece surface quality as well. Furthermore, costs of these cooling lubricants and the related environmental burden need to be considered. A current trend is to reduce the amount of lubricants that are used, e.g., when the Minimum Quantity Lubrication (MQL technique is applied. The lubricant or process liquid is thereby transported by the compressed air in the form of an aerosol to the contact area between the tool and workpiece. The cutting process was monitored during testing by the three following techniques: lubricant-free cutting, cutting with the use of a lubricant with the MQL technique, and only utilizing finish-turning and finish-face milling. The research allowed the authors to monitor the cutting power and mark the achieved surface quality in relation to the electrical power consumption of the cutting machine. In conclusions, the coherence between energy efficiency of the cutting machine and the workpiece surface quality regarding the used cooling lubricant is described.
USDOE Top-of-Rail Lubricant Project; FINAL

International Nuclear Information System (INIS)

Mohumad F. Alzoubi; George R. Fenske; Robert A. Erck; Amrit S. Boparai

2002-01-01

Lubrication of wheel/rail systems has been recognized for the last two decades as a very important issue for railroads. Energy savings and less friction and wear can be realized if a lubricant can be used at the wheel/rail interface. On the other hand, adverse influences are seen in operating and wear conditions if improper or excessive lubrication is used. Also, inefficiencies in lubrication need to be avoided for economic and environmental reasons. The top-of-rail (TOR) lubricant concept was developed by Texaco Corporation to lubricate wheels and rails effectively and efficiently. Tranergy Corporation has been developing its SENTRAEN 2000(trademark) lubrication system for the last ten years, and this revolutionary new high-tech on-board rail lubrication system promises to dramatically improve the energy efficiency, performance, safety, and track environment of railroads. The system is fully computer-controlled and ensures that all of the lubricant is consumed as the end of the train passes. Lubricant quantity dispensed is a function of grade, speed, curve, and axle load. Tranergy also has its LA4000(trademark) wheel and rail simulator, a lubrication and traction testing apparatus. The primary task of this project was collecting and analyzing the volatile and semivolatile compounds produced as the lubricant was used. The volatile organic compounds were collected by Carbotrap cartridges and analyzed by adsorption and gas chromatography/mass spectrometry (GC/MS). The semivolatile fraction was obtained by collecting liquid that dripped from the test wheel. The collected material was also analyzed by GC/MS. Both of these analyses were qualitative. The results indicated that in the volatile fraction, the only compounds on the Environmental Protection Agency's (EPA) Superfund List of Analytes detected were contaminants either in the room air or from other potential contamination sources in the laboratory. Similarly, in the semivolatile fraction none of the detected
Shear thickening in suspensions: the lubricated-to-frictional contact scenario

Science.gov (United States)

Morris, Jeffrey

2017-11-01

Suspensions of solid particles in viscous liquids can vary from low-viscosity liquids to wet granular materials or soft solids depending on the solids loading and the forces acting between particles. When the particles are very concentrated, these mixtures are ''dense suspensions.'' Dense suspensions often exhibit shear thickening, an increase in apparent viscosity as the shear rate is increased. In its most extreme form, order of magnitude increases in viscosity over such a narrow range in shear rate occur that the term discontinuous shear thickening (DST) is applied. DST is particularly striking as it occurs in the relatively simple case of nearly hard spheres in a Newtonian liquid, and is found to take place for submicron particles in colloidal dispersions to much larger particle corn starch dispersions. We focus on simulations of a recently developed ``lubricated-to-frictional'' rheology in which the interplay of viscous lubrication, repulsive surface forces, and contact friction between particle surfaces provides a scenario to explain DST. Our simulation method brings together elements of the discrete-element method from granular flow with a simplified Stokesian Dynamics, and can rationalize not only the abrupt change in properties with imposed shear rate (or shear stress), but also the magnitude of the change. The large change in properties is associated with the breakdown of lubricating films between particles, with activation of Coulomb friction between particles. The rate dependence is caused by the shearing forces driving particles to contact, overwhelming conservative repulsive forces between surfaces; the repulsive forces are representative of colloidal stabilization by surface charge or steric effects, e.g. due to adsorbed polymer. The results of simulation are compared to developments by other groups, including a number of experimental studies and a theory incorporating the same basic elements as the simulation. The comparison to experiments of the
Nanotribology of Symmetric and Asymmetric Liquid Lubricants

Directory of Open Access Journals (Sweden)

Shinji Yamada

2010-03-01

Full Text Available When liquid molecules are confined in a narrow gap between smooth surfaces, their dynamic properties are completely different from those of the bulk. The molecular motions are highly restricted and the system exhibits solid-like responses when sheared slowly. This solidification behavior is very dependent on the molecular geometry (shape of liquids because the solidification is induced by the packing of molecules into ordered structures in confinement. This paper reviews the measurements of confined structures and friction of symmetric and asymmetric liquid lubricants using the surface forces apparatus. The results show subtle and complex friction mechanisms at the molecular scale.
Lubricants : the lifeblood of wind turbines

Energy Technology Data Exchange (ETDEWEB)

Tremblay, Y. [Petro-Canada, Calgary, AB (Canada)

2009-07-01

With the significant investments in wind turbine equipment, companies need to exercise due diligence when it comes to the types of lubricants and fluids used. Mechanical and equipment issues can often be eliminated with improved maintenance practices and the appropriate selection of lubricants. This presentation discussed lubricants as being the lifeblood of wind turbines. The presentation first provided an overview and discussed wind turbine trends and application trends. The technical aspects of fluid formation were presented. Lubrication maintenance practices and oil monitoring were discussed. Last, key industry tests, and OEM specifications for bearings, gearboxes, and wind turbines were identified. It was concluded that improved maintenance practices in combination with the correct lubricant selection can address several operating problems. figs.
Double angle seal forming lubricant film

Science.gov (United States)

Ernst, William D.

1984-01-01

A lubricated piston rod seal which inhibits gas leaking from a high pressure chamber on one side of the seal to a low pressure chamber on the other side of the seal. A liquid is supplied to the surface of the piston rod on the low pressure side of the seal. This liquid acts as lubricant for the seal and provides cooling for the rod. The seal, which can be a plastic, elastomer or other material with low elastic modulus, is designed to positively pump lubricant through the piston rod/seal interface in both directions when the piston rod is reciprocating. The capacity of the seal to pump lubricant from the low pressure side to the high pressure side is less than its capacity to pump lubricant from the high pressure side to the low pressure side which ensures that there is zero net flow of lubricant to the high pressure side of the seal. The film of lubricant between the seal and the rod minimizes any sliding contact and prevents the leakage of gas. Under static conditions gas leakage is prevented by direct contact between the seal and the rod.
Reduced Need of Lubricity Additives in Soybean Oil Blends Under Boundary Lubrication Conditions

Science.gov (United States)

Converging prices of vegetable oils and petroleum, along with increased focus on renewable resources, gave more momentum to vegetable oil lubricants. Boundary lubrication properties of four Extreme Pressure (EP) additive blends in conventional Soy Bean Oil (SBO) and Paraffinic Mineral Oil (PMO) of ...
A lubricant

Energy Technology Data Exchange (ETDEWEB)

Parfenova, V.A.; Belov, P.S.; Guliaev, I.A.; Korenev, K.D.

1979-07-30

For the purpose of improving the thermo-oxidation stability of washing and protective properties, dithiophosphate of the metal having the formula ((pi-R-C/sub 6/H/sub 4/OCH/sub 2/-CH/sub 2/O)/sub 2/P(=S)S)/sub 2/M (where R is the alkyl of C/sub 8/--C/sub 12/ isostructure, M is either cadmium, barium, or zinc) (I) is added into the petroleum oil for the lubrication of car engine units and containing polyethylene oxyphenylpolyamine (PEP). The lubricant has the following composition, in %: PEP, 1 to 5; (I), 0.5 to 5; petroleum oil, up to 100. In order to produce a lubricant for petroleum oil, for example MT-16, PEF and (I) are added (R = octyl or dodecyl), it is heated up to 80/sup 0/ and mixed in a nitrogen current for one hour. The combination of the additives in the patented composition has synergistic activities and the oil being patented, according to operative properties, surpasses the oil with industrial dithiophosphate additive MNI-IP-22k.
Vegetable oil basestocks for lubricants

Directory of Open Access Journals (Sweden)

Garcés, Rafael

2011-03-01

Full Text Available The use of vegetable biodegradable basestocks for lubricant oils present several advantages over the much more extended mineral bases. These advantages refer to biodegradability, a renewable feedstock of local production, lubricant and viscosity index and lower costs than synthetic lubricant bases. Despite these benefits, their use in industry and motor vehicles is not yet extensive due their lower stability and higher pour points. Vegetable oils are esters of fatty acids and glycerol, and their physicochemical properties rely mainly on the composition of their acyl moieties. Thus, to assure the maximum levels of stability while maintaining acceptable behavior at low temperatures, monounsaturated fatty acids are preferred for this purpose. The presence of natural antioxidants also improves the properties of these vegetable based stocks as lubricants. These oils usually require additives to improve their viscosity value, oxidative stability and properties at low temperatures. In the present work, the different sources of vegetable oils appropriate for biolubricant production were reviewed. Their properties and the future improvement of the oil bases, oil based stock production, uses and additives are discussed.

El uso de bases vegetales biodegradables para aceites lubricantes presenta varias ventajas sobre las mucho más extendidas bases minerales. Estas ventajas se centran sobre todo en su biodegradabilidad, en ser un recurso renovable de producción local, en su lubricidad y en su índice de viscosidad, presentando además costes más bajos que las bases sintéticas. Sin embargo, estas ventajas no han extendido el uso de bases vegetales ni en industria ni en automoción debido a su menor estabilidad y sus mayores puntos críticos de fluidez. Los aceites vegetales son ésteres de ácidos grasos y glicerol y sus propiedades físico-químicas dependen principalmente de su composición acílica. Así, para asegurar los máximos niveles de
Lubricating graphene with a nanometer-thick perfluoropolyether

International Nuclear Information System (INIS)

Kozbial, Andrew; Li, Zhiting; Iasella, Steven; Taylor, Alexander T.; Morganstein, Brittni; Wang, Yongjin; Sun, Jianing; Zhou, Bo; Randall, Nicholas X.; Liu, Haitao; Li, Lei

2013-01-01

Due to its atomic thickness (thinness), the wear of graphene in nanoscale devices or as a protective coating is a serious concern. It is highly desirable to develop effective methods to reduce the wear of graphene. In the current paper, the effect of a nano-lubricant, perfluoropolyether, on the wear of graphene on different substrates is investigated. Graphene was synthesized by chemical vapor deposition (CVD) and characterized by Raman spectroscopy. The nano-lubricant is applied on the graphene by dip-coating. The friction and wear of graphene samples are characterized by nanotribometer, AFM, optical microscopy and Raman spectroscopy. The results showed that lubricating silicon/graphene with nano-lubricant reduces the friction but increases the wear. However, lubricating nickel/graphene with nano-lubricant has little effect on the friction but reduce the wear significantly. The underlying mechanism has been discussed on the basis of the graphene–substrate adhesion and the roughness. The current study provides guidance to the future design of graphene-containing devices. - Highlights: • The effect of a nano-lubricant on the friction and wear of CVD graphene was studied. • Lubricating Graphene/Si results in lower friction but higher wear. • Lubricating Ggraphene/Ni results in lower wear but unchanged friction. • The mechanisms were discussed based on the roughness and interfacial adhesion
Synthesis of sulfur-containing lubricant additives on the basis of fatty acid ethyl esters

Directory of Open Access Journals (Sweden)

Iurii S. Bodachivskyi

2016-12-01

Full Text Available The study reveals an energy-, resource- and eco-friendly method for preparation of sulfur-containing lubricant additives via interaction of fatty acid ethyl esters of rapeseed oil with elemental sulfur. The structure of synthesized compounds under various reactants ratio (5–50 wt.% of sulfur, duration (30–240 min and temperature of the process (160–215°С was investigated using various analytical techniques. According to the established data, aside from addition to double bonds, the side reaction of hydrogen substitution at α-methylene groups near these bonds occurs and induces the formation of conjugated systems and chromophoric sulfur-rich derivatives. Also, we found that increase of process duration evokes growth of polysulfane chains, in contrast to the raise of temperature, which leads to the formation of sulfur-containing heterocycles and hydrogen sulfide, as a result of elimination. Influence of accelerators on sulfurization of fatty acid ethyl esters was also examined. The most effective among them are mixtures of zinc dibutyldithiocarbamate with zinc oxide or stearic acid, which soften synthesis conditions and doubly decrease duration of the high-temperature stage. In addition, sulfur-containing compositions of ethyl esters and α-olefins, vulcanized esters by benzoyl peroxide, nonylphenols and zinc dinonylphenyldithiophosphate were designed. The study identified that lithium lubricant with sulfurized vulcanized esters provides improved tribological properties, in comparison with base lubricant or lubricant with the non-modified product.
Identifying lubricant options for compressor bearing designs

Science.gov (United States)

Karnaz, J.; Seeton, C.; Dixon, L.

2017-08-01

Today’s refrigeration and air conditioning market is not only driven by the environmental aspects of the refrigerants, but also by the energy efficiency and reliability of system operation. Numerous types of compressor designs are used in refrigeration and air conditioning applications which means that different bearings are used; and in some cases, multiple bearing types within a single compressor. Since only one lubricant is used, it is important to try to optimize the lubricant to meet the various demands and requirements for operation. This optimization entails investigating different types of lubricant chemistries, viscosities, and various formulation options. What makes evaluating these options more challenging is the refrigerant which changes the properties of the lubricant delivered to the bearing. Once the lubricant and refrigerant interaction are understood, through various test methods, then work can start on collaborating with compressor engineers on identifying the lubricant chemistry and formulation options. These interaction properties are important to the design engineer to make decisions on the adequacy of the lubricant before compressor tests are started. This paper will discuss the process to evaluate lubricants for various types of compressors and bearing design with focus on what’s needed for current refrigerant trends. In addition, the paper will show how the lubricant chemistry choice can be manipulated through understanding of the bearing design and knowledge of interaction with the refrigerant to maximize performance. Emphasis will be placed on evaluation of synthetic lubricants for both natural and synthetic low GWP refrigerants.
MODELING OF TEMPERATURE FIELDS IN A SOLID HEAT ACCUMULLATORS

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S. S. Belimenko

2016-10-01

Full Text Available Purpose. Currently, one of the priorities of energy conservation is a cost savings for heating in commercial and residential buildings by the stored thermal energy during the night and its return in the daytime. Economic effect is achieved due to the difference in tariffs for the cost of electricity in the daytime and at night. One of the most common types of devices that allow accumulating and giving the resulting heat are solid heat accumulators. The main purpose of the work: 1 software development for the calculation of the temperature field of a flat solid heat accumulator, working due to the heat energy accumulation in the volume of thermal storage material without phase transition; 2 determination the temperature distribution in its volumes at convective heat transfer. Methodology. To achieve the study objectives a heat transfer theory and Laplace integral transform were used. On its base the problems of determining the temperature fields in the channels of heat accumulators, having different cross-sectional shapes were solved. Findings. Authors have developed the method of calculation and obtained solutions for the determination of temperature fields in channels of the solid heat accumulator in conditions of convective heat transfer. Temperature fields over length and thickness of channels were investigated. Experimental studies on physical models and industrial equipment were conducted. Originality. For the first time the technique of calculating the temperature field in the channels of different cross-section for the solid heat accumulator in the charging and discharging modes was proposed. The calculation results are confirmed by experimental research. Practical value. The proposed technique is used in the design of solid heat accumulators of different power as well as full-scale production of them was organized.
21 CFR 880.6375 - Patient lubricant.

Science.gov (United States)

2010-04-01

... § 880.6375 Patient lubricant. (a) Identification. A patient lubricant is a device intended for medical... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Patient lubricant. 880.6375 Section 880.6375 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL...
Metal forming and lubrication

DEFF Research Database (Denmark)

Bay, Niels

2000-01-01

Lubrication is essential in most metal forming processes. The lubricant film has two basic functions, [1]: i. to separate the work piece and tool surfaces and ii. to cool the workpiece and the tool. Separation of the two surfaces implies lower friction facilitating deformation and lowering the tool...
Investigation on the effect of lubrication and forming parameters to the green compact generated from iron powder through warm forming route

International Nuclear Information System (INIS)

Rahman, M.M.; Nor, S.S.M.; Rahman, H.Y.

2011-01-01

In order to generate green compacts of iron ASC 100.29 powder at above ambient temperature and below its recrystallization temperature, a warm compaction rig is designed and fabricated which can be operated at various temperature and load. The aim of this paper is to present the outcomes of an investigation on the effect of lubrication and forming parameters, i.e., load and temperature to the green compacts generated through warm compaction route. The feedstock was prepared by mechanically mixing the main powder constituent, i.e., iron ASC 100.29 powder with different weight percent of zinc stearate at different mixing time. Compaction load was varied from 105 kN to 125 kN using simultaneous compaction mechanism. The microstructures of the green compacts were analyzed by Scanning Electron Microscopy (SEM), and the mechanical properties are measured through density measurement, hardness test and electrical conductivity test. The study found that increase in compaction load as well as forming temperature give improved microstructure and mechanical properties. It is also found that effects of lubrication to the mechanical properties of green compacts are strongly dependant on the lubricant content as well as mixing time of iron powder with the lubricant.
Modified Ionic Liquid-Based High-Performance Lubricants for Robotic Operations, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — NASA requires a highly efficient lubrication system for robotic operations, which will withstand very low temperatures (20 K) and other rigors of outer space and...
Laboratory services series: a lubrication program

Energy Technology Data Exchange (ETDEWEB)

Bowen, H.B.; Miller, T.L.

1976-05-01

The diversity of equipment and operating conditions at a major national research and development laboratory requires a systematic, effective lubrication program. The various phases of this program and the techniques employed in formulating and administering this program are discussed under the following topics: Equipment Identification, Lubrication Requirements, Assortment of Lubricants, Personnel, and Scheduling.
Laboratory services series: a lubrication program

International Nuclear Information System (INIS)

Bowen, H.B.; Miller, T.L.

1976-05-01

The diversity of equipment and operating conditions at a major national research and development laboratory requires a systematic, effective lubrication program. The various phases of this program and the techniques employed in formulating and administering this program are discussed under the following topics: Equipment Identification, Lubrication Requirements, Assortment of Lubricants, Personnel, and Scheduling
Tribological properties of Ti-doped DLC coatings under ionic liquids lubricated conditions

International Nuclear Information System (INIS)

Feng Xin; Xia Yanqiu

2012-01-01

In this paper, titanium doped diamond-like carbon (Ti-DLC) coatings were prepared onto AISI 52100 steel substrates using medium frequency magnetic sputtering process, and were analyzed using the Raman and transmission electron microscope (TEM). Two kinds of 1,3-dialkyl imidazolium ionic liquids (ILs) were synthesized and evaluated as lubricants for Ti-DLC/steel contacts at room temperature, and PFPE as comparison lubricant. The tribological properties of the ILs were investigated using a ball-on-disk type UMT reciprocating friction tester. The results indicated that the ILs have excellent friction-reducing properties, the friction coefficient kept at a relatively stable value of 0.07-0.06, which was reduced approximately by 47% compared with perfluoropolyether (PFPE). The worn surfaces of Ti-DLC coatings were observed and analyzed using a MICROXAM-3D non-contact surface profiler, scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). The Ti-DLC coatings using ionic liquids lubricating systems are considered as potential lubricating system in vacuum and space moving friction pairs.

Integrated Interface Strategy toward Room Temperature Solid-State Lithium Batteries.

Science.gov (United States)

Ju, Jiangwei; Wang, Yantao; Chen, Bingbing; Ma, Jun; Dong, Shanmu; Chai, Jingchao; Qu, Hongtao; Cui, Longfei; Wu, Xiuxiu; Cui, Guanglei

2018-04-25

Solid-state lithium batteries have drawn wide attention to address the safety issues of power batteries. However, the development of solid-state lithium batteries is substantially limited by the poor electrochemical performances originating from the rigid interface between solid electrodes and solid-state electrolytes. In this work, a composite of poly(vinyl carbonate) and Li 10 SnP 2 S 12 solid-state electrolyte is fabricated successfully via in situ polymerization to improve the rigid interface issues. The composite electrolyte presents a considerable room temperature conductivity of 0.2 mS cm -1 , an electrochemical window exceeding 4.5 V, and a Li + transport number of 0.6. It is demonstrated that solid-state lithium metal battery of LiFe 0.2 Mn 0.8 PO 4 (LFMP)/composite electrolyte/Li can deliver a high capacity of 130 mA h g -1 with considerable capacity retention of 88% and Coulombic efficiency of exceeding 99% after 140 cycles at the rate of 0.5 C at room temperature. The superior electrochemical performance can be ascribed to the good compatibility of the composite electrolyte with Li metal and the integrated compatible interface between solid electrodes and the composite electrolyte engineered by in situ polymerization, which leads to a significant interfacial impedance decrease from 1292 to 213 Ω cm 2 in solid-state Li-Li symmetrical cells. This work provides vital reference for improving the interface compatibility for room temperature solid-state lithium batteries.
Influences of lubricant pocket geometry and working conditions upon micro lubrication mechanisms in upsetting and strip drawing

DEFF Research Database (Denmark)

Shimizu, Ichiro; Martins, P. A. F.; Bay, Niels

2010-01-01

, during upsetting and strip drawing, by means of a rigid-viscoplastic finite-element formulation. Special emphasis is placed on the effect of pocket geometry on the build-up of hydrostatic pressure, which is responsible for the onset of micro-lubrication mechanisms. A good agreement is found between......Micro-lubricant pockets located in the surface of plastically deforming workpieces are recognised to improve the performance of fluid lubrication in a metal-forming process. This work investigates the joint influence of pocket geometry and process working conditions on micro-lubrication mechanisms...
Novel solid – solid phase change material based on polyethylene glycol and cellulose used for temperature stabilisation

Directory of Open Access Journals (Sweden)

Wojda Marta

2014-01-01

Full Text Available Thermal management is one of crucial issues in the development of modern electronic devices. In the recent years interest in phase change materials (PCMs as alternative cooling possibility has increased significantly. Preliminary results concerning the research into possibility of the use of solid-solid phase change materials (S-S PCMs for stabilisation temperature of electronic devices has been presented in the paper. Novel solid-solid phase change material based on polyethylene glycol and cellulose has been synthesized. Attempt to improve its thermal conductivity has been taken. Material has been synthesized for the purpose of stabilisation of temperature of electronic devices.
Performance of palm oil as a biobased machining lubricant when drilling inconel 718

Directory of Open Access Journals (Sweden)

Abd Rahim Erween

2017-01-01

Full Text Available Metalworking fluid acts as cooling and lubrication agent at the cutting zone in the machining process. However, conventional Metalworking fluid such mineral oil gives negative impact on the human and environment. Therefore, the manufacture tends to substitute the mineral oil to bio-based oil such as vegetables and synthetic oil. In this paper, the drilling experiment was carried out to evaluate the efficiency of palm oil and compare it with minimal quantity lubrication technique using synthetic ester, flood coolant and air blow with respect to cutting temperature, cutting force, torque and tool life. The experimental results showed that the application of palm oil under minimal quantity lubrication condition as the cutting fluid was more efficient process as it improves the machining performances.
Self lubrication of bitumen froth in pipelines

International Nuclear Information System (INIS)

Joseph, D.D.

1997-01-01

In this paper I will review the main properties of water lubricated pipelines and explain some new features which have emerged from studies of self-lubrication of Syncrudes' bitumen froth. When heavy oils are lubricated with water, the water and oil are continuously injected into a pipeline and the water is stable when in a lubricating sheath around the oil core. In the case of bitumen froth obtained from the Alberta tar sands, the water is dispersed in the bitumen and it is liberated at the wall under shear; water injection is not necessary because the froth is self-lubricating
Lubricant flow analysis for effective lubrication of tractor forward/reverse clutch

Directory of Open Access Journals (Sweden)

Daekyung Noh

2017-04-01

Full Text Available Owing to the high power requirements of tractors, their low-power transmission gears often experience durability problems such as burning of the clutch. The operation of tractors under high load conditions also causes clutch slip, with the consequent longer operation duration exacerbating the burning of the friction plate. Solving this problem requires effective lubricant distribution. This was achieved in the present study by the development of an analysis model for predicting the lubricant flow rate. The reliability of the model was verified by comparing its predictions for various operation conditions with experimental measurements. Using the model, it was determined that effective distribution of the lubricant could be achieved without significant modification of the system, by only adjusting the gaps between the clutch piston and the housing, and between the separation plates and the case. Keywords: Mechanical engineering
Ecotoxicological study of used lubricating oil

International Nuclear Information System (INIS)

Wong, P.K.; Chan, W.L.; Wang, J.; Wong, C.K.

1995-01-01

Used lubricating oil is more toxic than crude oil and fuel oil since it contains comparatively high levels of heavy metals and polycyclic aromatic hydrocarbons (PAHs). No detail toxicological study has been conducted to evaluate the hazards of used lubricating oil to the environment. This study reports a battery of bioassays using bacteria (Microtox test and Mutatox test), algae, amphipod and shrimp larvae to determine the toxicity of water soluble fraction of used lubricating oil. The results will be used to formulate a complete and extensive ecotoxicological assessment of the impacts of used lubricating oil on aquatic environment
Application of Artificial Neural Network and Response Surface Methodology in Modeling of Surface Roughness in WS2 Solid Lubricant Assisted MQL Turning of Inconel 718

Science.gov (United States)

Maheshwera Reddy Paturi, Uma; Devarasetti, Harish; Abimbola Fadare, David; Reddy Narala, Suresh Kumar

2018-04-01

In the present paper, the artificial neural network (ANN) and response surface methodology (RSM) are used in modeling of surface roughness in WS2 (tungsten disulphide) solid lubricant assisted minimal quantity lubrication (MQL) machining. The real time MQL turning of Inconel 718 experimental data considered in this paper was available in the literature [1]. In ANN modeling, performance parameters such as mean square error (MSE), mean absolute percentage error (MAPE) and average error in prediction (AEP) for the experimental data were determined based on Levenberg–Marquardt (LM) feed forward back propagation training algorithm with tansig as transfer function. The MATLAB tool box has been utilized in training and testing of neural network model. Neural network model with three input neurons, one hidden layer with five neurons and one output neuron (3-5-1 architecture) is found to be most confidence and optimal. The coefficient of determination (R2) for both the ANN and RSM model were seen to be 0.998 and 0.982 respectively. The surface roughness predictions from ANN and RSM model were related with experimentally measured values and found to be in good agreement with each other. However, the prediction efficacy of ANN model is relatively high when compared with RSM model predictions.
New lubrication concepts for environmental friendly machines. Tribological, thermophysical and viscometric properties of lubricants interacting with triboactive materials

Energy Technology Data Exchange (ETDEWEB)

Schmidt, R.; Klingenberg, G. [Physikalisch-Technische Bundesanstalt, Braunschweig (Germany); Woydt, M. [Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin (Germany)

2006-07-01

The present research report was elaborated in close cooperation with Renault SAS, FUCHS Petrolub AG and Ingenieurgesellschaft Auto und Verkehr (IAV). The use of alternative oils for the lubrication of automobile engines has a potential of ecological and technical advantages. It requires the detailed knowledge of several thermophysical and viscometric properties in a large temperature range (mapping). Therefore, the following properties of up to twenty-eight different oils have been measured in the temperature range from 22 C to 150 C: density, heat capacity, thermal conductivity, viscosity at ambient pressure, viscosity under shear rates above 10{sup 6} s{sup -1}, and the viscosity at elevated pressures (maximum 100 MPa). The last two have been measured with a substantially improved and a newly developed apparatus, respectively. The pressure-viscosity coefficient has been measured on four hydrocarbon-based, factory-fill oils, a paraffin oil and twenty-three alternative oils. Nine of the alternative oils are based partly or completely on esters, the other fourteen on polyglycols, two of them additionally on water. Based on the piston ring/cylinder liner simulation tests of BAM performed outside of engines and the SRV {sup registered} tests both performed only under conditions of mixed/boundary lubrication, it is reasonable that thermally sprayed TiO{sub x}-based, Ti{sub n-2}Cr{sub 2}O{sub 2n-1} and (Ti,Mo)(C,N)+23NiMo piston ring coatings, so called 'lubricious or triboactive oxides', can substitute common materials and serve as a promising alternative to commercial piston ring coatings made of strategic Molybdenum and super-finishing intensive blends of WC/Cr{sub 3}C{sub 2}. Some couples qualified for 'zero' wear. In combination with bionotox ester- and polyglycol-based lubricants the coefficient of friction can be reduced fulfilling simultaneously stronger European exhaust emission regulations. Thermally sprayed Ti-based coatings with their
Lubricant test for punching and blanking

DEFF Research Database (Denmark)

Olsson, David Dam; Bay, Niels; Andreasen, Jan Lasson

2003-01-01

Punching/blanking is one of the tribologically wise most severe metal forming processes.Insu $cient lubrication leads to heavy pick-up of work piece material on the punch stem,bad tolerances and eventual breakdown of the punch due to excessive backstroke force,especially in case of tribologically...... of alternative lubricants the present paper describes a new lubricant test for punching....
Investigation on Rubber-Modified Polybenzoxazine Composites for Lubricating Material Applications

Science.gov (United States)

Jubsilp, Chanchira; Taewattana, Rapiphan; Takeichi, Tsutomu; Rimdusit, Sarawut

2015-10-01

Effects of liquid amine-terminated butadiene-acrylonitrile (ATBN) on the properties of bisphenol-A/aniline-based polybenzoxazine (PBA-a) composites were investigated. Liquid ATBN decreased gel time and lowered curing temperature of the benzoxazine resin (BA-a). The PBA-a/ATBN-based self-lubricating composites resulted in substantial enhancement regarding their tribological, mechanical, and thermal properties. The inclusion of the ATBN at 5% by weight was found decreasing the friction coefficient and improved wear resistance of the PBA-a/ATBN composites. Flexural modulus and glass transition temperature of the PBA-a composite samples added the ATBN was constant within the range of 1-5% by weight. A plausible wear mechanism of the composites is proposed based on their worn surface morphologies. Based on the findings in this work, it seems that the obtained PBA-a/ATBN self-lubricating composites would have high potential to be used for bearing materials where low friction coefficient, high wear resistance, and modulus with good thermal property are required.
Measurement of dynamic viscoelasticity of confined lubricant by using oscillating optical fiber probe

International Nuclear Information System (INIS)

Itoh, S; Fukuzawa, K; Hamamoto, Y; Zhang, H

2007-01-01

When a liquid is confined in molecularly narrow gaps, it shows characteristic viscoelasticity such as enhanced viscosity or prolonged relaxation time. In order to investigate the dynamic viscoelasticity of the confined liquid, we developed a new shear force measuring method that uses a ball-ended optical fiber as a shearing probe. Our method can measure the shear force of 0.1 nN order with the oscillation frequency of up to 10 kHz. In addition, the gap that confines the liquid can be set at any constant value ranging from 10 μm to 0.1 nm. In this study, we measured the gap dependence of viscoelasticity of confined liquid lubricants. The gap ranged from 200 nm to a few nm. The tested lubricant was Fomblin Z03 and Zdo14000. A magnetic disk was used as the solid substrate. Oscillation frequency was set at 800 Hz. The experiment showed the viscosity of both Z03 and Zdo14000 gradually increased as the confining gap decreased. The gap width where the viscosity increase started was wider than 100 nm, which is dozens of times larger than the gyration diameter of lubricant molecules. Although Z03 and Zdo14000 have negligibly small elasticity in a bulk state, elasticity suddenly appeared at gaps less than about 8 nm with Zdo14000, and at gaps less than about 4 nm with Z03. Stronger affinity of Zdo14000 molecules to the solid substrate could cause the wider gap width of elasticity appearance
Nuclear fuel handling grapple carriage with self-lubricating bearing

International Nuclear Information System (INIS)

Wade, E.E.

1978-01-01

Disclosed is a nuclear fuel handling grapple carriage having a bearing with a lubricant reservoir that is capable of being refilled when the bearing and reservoir are submerged in a lubricant pool. The lubricant reservoir supplies lubricant to the bearing while the bearing allows a small amount of lubricant to leak passed appropriately placed seals creating a positive out flow of lubricant thereby preventing foreign material from entering the bearing
AW-101 entrained solids - Solubility versus temperature

International Nuclear Information System (INIS)

GJ Lumetta; RC Lettau; GF Piepel

2000-01-01

This report describes the results of a test conducted by Battelle to assess the solubility of the solids entrained in the diluted AW-101 low-activity waste (LAW) sample. BNFL requested Battelle to dilute the AW-1-1 sample using de-ionized water to mimic expected plant operating conditions. BNFL further requested Battelle to assess the solubility of the solids present in the diluted AW-101 sample versus temperature conditions of 30, 40, and 50 C. BNFL requested these tests to assess the composition of the LAW supernatant and solids versus expected plant-operating conditions. The work was conducted according to test plan BNFL-TP-29953-7, Rev. 0, Determination of the Solubility of LAW Entrained Solids. The test went according to plan, with no deviations from the test plan
Method for calculating solid-solid phase transitions at high temperature: An application to N2O

International Nuclear Information System (INIS)

Kuchta, B.; Etters, R.D.

1992-01-01

Two similar techniques for calculating solid-solid phase transitions at high temperatures are developed, where the contribution of the entropy may be a decisive factor. They utilize an artificial reversible path from one phase to another by application of a control parameter. Thermodynamic averages are calculated using constant-volume and constant-pressure Monte Carlo techniques. An application to N 2 O at room temperature shows that the cubic Pa3 to orthorhombic Cmca transition occurs near 4.9-GPa pressure, very close to the value calculated at very low temperatures. These results support experimental evidence that the transition pressure is virtually independent of temperature
Intermetallic Nickel-Titanium Alloys for Oil-Lubricated Bearing Applications

Science.gov (United States)

DellaCorte, C.; Pepper, S. V.; Noebe, R.; Hull, D. R.; Glennon, G.

2009-01-01

An intermetallic nickel-titanium alloy, NITINOL 60 (60NiTi), containing 60 wt% nickel and 40 wt% titanium, is shown to be a promising candidate material for oil-lubricated rolling and sliding contact applications such as bearings and gears. NiTi alloys are well known and normally exploited for their shape memory behavior. When properly processed, however, NITINOL 60 exhibits excellent dimensional stability and useful structural properties. Processed via high temperature, high-pressure powder metallurgy techniques or other means, NITINOL 60 offers a broad combination of physical properties that make it unique among bearing materials. NITINOL 60 is hard, electrically conductive, highly corrosion resistant, less dense than steel, readily machined prior to final heat treatment, nongalling and nonmagnetic. No other bearing alloy, metallic or ceramic encompasses all of these attributes. Further, NITINOL 60 has shown remarkable tribological performance when compared to other aerospace bearing alloys under oil-lubricated conditions. Spiral orbit tribometer (SOT) tests were conducted in vacuum using NITINOL 60 balls loaded between rotating 440C stainless steel disks, lubricated with synthetic hydrocarbon oil. Under conditions considered representative of precision bearings, the performance (life and friction) equaled or exceeded that observed with silicon nitride or titanium carbide coated 440C bearing balls. Based upon this preliminary data, it appears that NITINOL 60, despite its high titanium content, is a promising candidate alloy for advanced mechanical systems requiring superior and intrinsic corrosion resistance, electrical conductivity and nonmagnetic behavior under lubricated contacting conditions.
Rapid Thermal Annealing of Cathode-Garnet Interface toward High-Temperature Solid State Batteries.

Science.gov (United States)

Liu, Boyang; Fu, Kun; Gong, Yunhui; Yang, Chunpeng; Yao, Yonggang; Wang, Yanbin; Wang, Chengwei; Kuang, Yudi; Pastel, Glenn; Xie, Hua; Wachsman, Eric D; Hu, Liangbing

2017-08-09

High-temperature batteries require the battery components to be thermally stable and function properly at high temperatures. Conventional batteries have high-temperature safety issues such as thermal runaway, which are mainly attributed to the properties of liquid organic electrolytes such as low boiling points and high flammability. In this work, we demonstrate a truly all-solid-state high-temperature battery using a thermally stable garnet solid-state electrolyte, a lithium metal anode, and a V 2 O 5 cathode, which can operate well at 100 °C. To address the high interfacial resistance between the solid electrolyte and cathode, a rapid thermal annealing method was developed to melt the cathode and form a continuous contact. The resulting interfacial resistance of the solid electrolyte and V 2 O 5 cathode was significantly decreased from 2.5 × 10 4 to 71 Ω·cm 2 at room temperature and from 170 to 31 Ω·cm 2 at 100 °C. Additionally, the diffusion resistance in the V 2 O 5 cathode significantly decreased as well. The demonstrated high-temperature solid-state full cell has an interfacial resistance of 45 Ω·cm 2 and 97% Coulombic efficiency cycling at 100 °C. This work provides a strategy to develop high-temperature all-solid-state batteries using garnet solid electrolytes and successfully addresses the high contact resistance between the V 2 O 5 cathode and garnet solid electrolyte without compromising battery safety or performance.
Influence of Base Oil Polarity on the Transient Shear Flow of Biodegradable Lubricating Greases

Directory of Open Access Journals (Sweden)

Martin Fiedler

2015-09-01

Full Text Available The scope of this study is to elucidate the physical mechanisms influencing the transient flow behavior of lubricating greases based on biogenic oleochemicals from a polarity point of view. This includes the mutually interacting influence of base oil polarity and thickening agents on the rheologically-measured mechanical structural degradation in transient shear flow. Due to the high temperature dependence of Keesom forces in the background of polar-active bond mechanisms, the analysis of the transient flow response as a function of temperature allows to attribute the observed influences to differences in base oil polarity. In general, clay-thickened greases show a greater tendency to be rheologically influenced by base oil polarities than soap-thickened lubricating greases.
Nanopolishing by colloidal nanodiamond in elastohydrodynamic lubrication

Energy Technology Data Exchange (ETDEWEB)

Shirvani, Khosro A., E-mail: Khosro.asgharishir@bison.howard.edu; Mosleh, Mohsen; Smith, Sonya T. [Howard University, Department of Mechanical Engineering (United States)

2016-08-15

In this paper, the feasibility of using explosion synthesized diamond nanoparticles with an average particle size (APS) of 3–5 nm with a concentration of 1 % by weight for improving lubrication and friction in elastohydrodynamic lubrication (EHL) was investigated. Owing to the orders of magnitude increase in the viscosity of the lubricant in the EHL contact zone, diamond nanoparticles in the lubricant polish the surfaces at the nanoscale which decreases the composite roughness of contacting surfaces. The reduced composite roughness results in an increased film thickness ratio which yields lower friction. In the numerical analysis, governing equations of lubricant flow in the full elastohydrodynamic lubrication were solved, and the shear stress distribution over the fluid film was calculated. Using an abrasion model and the shear stress distribution profile, the material removal by the nanofluid containing nanoparticles and the resultant surface roughness were determined. The numerical analysis showed that in full EHL regime, the nanolubricant can reduce the composite roughness of moving surfaces. Experimental results from prior studies which exhibited surface polishing by such nanolubricants in boundary, mixed, and full elastohydrodynamic lubrication were used for comparison to the numerical model.
Nanopolishing by colloidal nanodiamond in elastohydrodynamic lubrication

Science.gov (United States)

Shirvani, Khosro A.; Mosleh, Mohsen; Smith, Sonya T.

2016-08-01

In this paper, the feasibility of using explosion synthesized diamond nanoparticles with an average particle size (APS) of 3-5 nm with a concentration of 1 % by weight for improving lubrication and friction in elastohydrodynamic lubrication (EHL) was investigated. Owing to the orders of magnitude increase in the viscosity of the lubricant in the EHL contact zone, diamond nanoparticles in the lubricant polish the surfaces at the nanoscale which decreases the composite roughness of contacting surfaces. The reduced composite roughness results in an increased film thickness ratio which yields lower friction. In the numerical analysis, governing equations of lubricant flow in the full elastohydrodynamic lubrication were solved, and the shear stress distribution over the fluid film was calculated. Using an abrasion model and the shear stress distribution profile, the material removal by the nanofluid containing nanoparticles and the resultant surface roughness were determined. The numerical analysis showed that in full EHL regime, the nanolubricant can reduce the composite roughness of moving surfaces. Experimental results from prior studies which exhibited surface polishing by such nanolubricants in boundary, mixed, and full elastohydrodynamic lubrication were used for comparison to the numerical model.

The Wear Characteristics of Heat Treated Manganese Phosphate Coating Applied to AlSi D2 Steel with Oil Lubricant

Directory of Open Access Journals (Sweden)

Venkatesan Alankaram

2012-12-01

Full Text Available Today, in the area of material design conversion coatings play an important role in the applications where temperature, corrosion, oxidation and wear come in to play. Wear of metals occurs when relative motion between counter-surfaces takes place, leading to physical or chemical destruction of the original top layers. In this study, the tribological behaviour of heat treated Manganese phosphate coatings on AISI D2 steel with oil lubricant was investigated. The Surface morphology of manganese phosphate coatings was examined by Scanning Electron Microscope (SEM and Energy Dispersive X-ray Spectroscopy (EDX .The wear tests were performed in a pin on disk apparatus as per ASTM G-99 Standard. The wear resistance of the coated steel was evaluated through pin on disc test using a sliding velocity of 3.0m/s under Constant loads of 40 N and 100 N with in controlled condition of temperature and humidity. The Coefficient of friction and wear rate were evaluated. Wear pattern of Manganese phosphate coated pins with oil lubricant, Heat treated Manganese phosphate coated pins with oil lubricant were captured using Scanning Electron Microscope (SEM. The results of the wear test established that the heat treated manganese phosphate coating with oil lubricant exhibited the lowest average coefficient of friction and the lowest wear loss up to 6583 m sliding distance under 40 N load and 3000 m sliding distance even under 100 N load respectively. The Wear volume and temperature rise in heat treated Manganese Phosphate coated pins with oil lubricant is lesser than the Manganese Phosphate coated pins with oil lubricant
Molecular dynamics simulations of elasto-hydrodynamic lubrication and boundary lubrication for automotive tribology

International Nuclear Information System (INIS)

Washizu, Hitoshi; Sanda, Shuzo; Hyodo, Shi-aki; Ohmori, Toshihide; Nishino, Noriaki; Suzuki, Atsushi

2007-01-01

Friction control of machine elements on a molecular level is a challenging subject in vehicle technology. We describe the molecular dynamics studies of friction in two significant lubrication regimes. As a case of elastohydrodynamic lubrication, we introduce the mechanism of momentum transfer related to the molecular structure of the hydrocarbon fluids, phase transition of the fluids under high pressure, and a submicron thickness simulation of the oil film using a tera-flops computer. For boundary lubrication, the dynamic behavior of water molecules on hydrophilic and hydrophobic silicon surfaces under a shear condition is studied. The dynamic structure of the hydrogen bond network on the hydrophilic surface is related to the low friction of the diamond-like carbon containing silicon (DLC-Si) coating
Ionanocarbon Lubricants. The Combination of Ionic Liquids and Carbon Nanophases in Tribology

Directory of Open Access Journals (Sweden)

María-Dolores Avilés

2017-05-01

Full Text Available The present overview will focus on the tribological applications of what we have called ionanocarbon lubricants, that is, the combination of carbon nanophases (graphene, carbon nanotubes, nanodiamonds, carbon nanodots and room-temperature ionic liquids in new dispersions, blends, or modified nanostructures and their use in tribology, lubrication, and surface engineering as friction-reducing, antiwear, and surface-protecting agents in thin films and composite materials. Further research lines and factors that limit the practical applications of the outstanding research results are also highlighted. The very recent results in these lines of research make this a necessary brief review.
Oleic Acid Based Polyesters of Trimethylolpropane and Pentaerythritol for Bio lubricant Application

International Nuclear Information System (INIS)

Hamizah Ammarah Mahmud; Nadia Salih; Jumat Salimon

2015-01-01

The production of polyesters based on oleic acid and trimethylolpropane (TMP) or pentaerythritol (PE) as potential bio lubricant were carried out. The esterification processes between oleic acid with TMP or PE were carried out using sulfuric acid as a catalyst. The esterification process produced high yield between 92 %-94 % w/w respectively. The formation of polyesters was confirmed using gas chromatography (GC-FID), Fourier Transform Infrared Spectroscopy (FTIR) and Nuclear Magnetic Resonance (NMR). The polyesters were analyzed for basic lubrication physicochemical properties. The results showed that polyesters of both TMP and PE having high viscosity index between 200-309, good pour points ranging from -42 to -59 degree Celsius and high flash points of 280 - 300 degree Celsius respectively. The polyesters also showed good thermal oxidative stability with TGA onset temperatures above 180 degree Celsius. In general both products are plausible to be used as bio lubricant for industrial application. (author)
Nanoscale Organic−Inorganic Hybrid Lubricants

KAUST Repository

Kim, Daniel

2011-03-15

Silica (SiO2) nanoparticles densely grafted with amphiphilic organic chains are used to create a family of organic-inorganic hybrid lubricants. Short sulfonate-functionalized alkylaryl chains covalently tethered to the particles form a dense corona brush that stabilizes them against aggregation. When these hybrid particles are dispersed in poly-α-olefin (PAO) oligomers, they form homogeneous nanocomposite fluids at both low and high particle loadings. By varying the volume fraction of the SiO2 nanostructures in the PAO nanocomposites, we show that exceptionally stable hybrid lubricants can be created and that their mechanical properties can be tuned to span the spectrum from simple liquids to complex gels. We further show that these hybrid lubricants simultaneously exhibit lower interfacial friction coefficients, enhanced wear and mechanical properties, and superior thermal stability in comparison with either PAO or its nanocomposites created at low nanoparticle loadings. Profilometry and energy dispersive X-ray spectroscopic analysis of the wear track show that the enhanced wear characteristics in PAO-SiO2 composite lubricants originate from two sources: localization of the SiO2 particles into the wear track and extension of the elastohydrodynamic lubrication regime to Sommerfeld numbers more than an order of magnitude larger than for PAO. © 2011 American Chemical Society.
Dispersants in an organic medium: synthesis and physicochemical study of dispersants for fuels and lubricants; Dispersants en milieu organique: synthese et etude physicochimique de dispersants pour carburants et lubrifiants

Energy Technology Data Exchange (ETDEWEB)

Dubois-Clochard, M.C.

1998-11-19

Carbonaceous deposits coming from the fuel and the lubricant are known to form over time at critical locations in an engine. In general, the deposits have an adverse effect on four functional areas which are the fuel metering system, the intake system, the lubrication system and the combustion chambers. These deposits can degrade vehicle performance and drive-ability, reduce fuel economy, increase fuel consumption and pollutant emissions and may lead to the destruction of the engine. In order to remedy these problems, detergent-dispersant additives are used in fuels and lubricants to avoid or decrease deposit adhesion on metallic surfaces and prevent from deposit aggregation. These products are mainly polymer surfactants and in this work, poly-iso-butenyl-succinimide of different structures have been studied. Firstly, 'comb like' polymers have been synthesized. Then they have been compared to classical di-bloc additives in terms of performance and action mechanism. These additives are adsorbed from their hydrophilic polyamine part on the acidic functions of the carbon black surface chosen as an engine deposit model and on the aluminium oxide function of an aluminium powder chosen as an engine wall model. The adsorption increases with temperature on the two solids. Their affinity with the solid surface increases with the length of the hydrophilic part. In the same way, changing the di-bloc structure for a comb like one lead to a better adsorption. At low concentration, it has been shown that the adsorption phenomenon was irreversible, due to the polymer structure of the polar part. Depending on the space required by the hydrophilic part on the solid surface, a more of less dense monolayer is formed. At higher concentrations, an important increase of the adsorbed amount appears. This phenomenon is totally reversible showing that the interactions additive / additive are weak. The dispersing efficiency of a comb like structure is better than a di-bloc one as
Limits of Lubrication in

DEFF Research Database (Denmark)

Olsson, David Dam

as delivered stainless steel surfaces implying microstructure changes in terms of larger ratio of closed lubricant pockets due to selective grain boundary etching. Strategic surfaces have also been created by macroscopic texturing using spherical indentations having a very small edge slope in order to promote...... by strategic surfaces in comparison to normal stainless steel surfaces implying a larger extent of bi-axial stretching. Numerical simulations have been applied in order to evaluate limits of lubrication in the simulative strip reduction based on predictions of critical parameters appearing in terms......-models corresponds well to experimental results in terms of lubricant film breakdown and subsequently pick-up development. Punching and blanking have been investigated regarding tribological conditions in case of using stainless steel workpiece materials. However, this has called for development of a new test method...
Bismuth nanoparticles synthesized by laser ablation in lubricant oils for tribological tests

Energy Technology Data Exchange (ETDEWEB)

Flores-Castañeda, M., E-mail: mar.floc@hotmail.com [Universidad Autónoma del Estado de México, Av. Instituto Literario No. 100, Oriente Col. Centro, Toluca, Estado de México C.P. 50000, México (Mexico); Instituto Nacional de Investigaciones Nucleares, Carretera México-Toluca s/n, La Marquesa, Ocoyoacac, Edo. de México C.P. 52750, México (Mexico); Camps, E. [Instituto Nacional de Investigaciones Nucleares, Carretera México-Toluca s/n, La Marquesa, Ocoyoacac, Edo. de México C.P. 52750, México (Mexico); Camacho-López, M. [Universidad Autónoma del Estado de México, Av. Instituto Literario No. 100, Oriente Col. Centro, Toluca, Estado de México C.P. 50000, México (Mexico); Muhl, S. [Instituto de Investigación en Materiales (UNAM), Circuito Exterior, Ciudad Universitaria, Coyoacán, 04510 México, D.F., México (Mexico); and others

2015-09-15

Highlights: • Bismuth nanoparticles have been obtained by laser ablation of solids in liquids. • The technique allows controlling the size and concentration of the samples. • Bi np’s in base oils can improve the tribological characteristics of the lubricant. - Abstract: The improvement of the tribological properties of mineral base oils through the addition of bismuth nanoparticles as an additive, together with the idea of obtaining lubricants free of heavy metals, was evaluated. Bismuth nanoparticles were produced directly in the heavy and light viscosity mineral base oils (BS900 and BS6500) using the technique of laser ablation of solids immersed in liquids. Transmission electron microscopy measurements showed the presence of pure bismuth nanoparticles. Small Angle X-ray Scattering (SAXS) measurements showed that the average size of the nanoparticles was between 7 and 65 nm depending on the experimental conditions used. The tribological properties of the base oil with the bismuth nanoparticles additives were evaluated using a four-ball tester. Tests were performed using the base oil with and without Bi nanoparticles. It was observed that the coefficient of friction of the oil decrease with an increasing concentration of the nanoparticles. The results also showed that the wear rate was reduced when the Bi nanoparticle additives were used.
Bismuth nanoparticles synthesized by laser ablation in lubricant oils for tribological tests

International Nuclear Information System (INIS)

Flores-Castañeda, M.; Camps, E.; Camacho-López, M.; Muhl, S.

2015-01-01

Highlights: • Bismuth nanoparticles have been obtained by laser ablation of solids in liquids. • The technique allows controlling the size and concentration of the samples. • Bi np’s in base oils can improve the tribological characteristics of the lubricant. - Abstract: The improvement of the tribological properties of mineral base oils through the addition of bismuth nanoparticles as an additive, together with the idea of obtaining lubricants free of heavy metals, was evaluated. Bismuth nanoparticles were produced directly in the heavy and light viscosity mineral base oils (BS900 and BS6500) using the technique of laser ablation of solids immersed in liquids. Transmission electron microscopy measurements showed the presence of pure bismuth nanoparticles. Small Angle X-ray Scattering (SAXS) measurements showed that the average size of the nanoparticles was between 7 and 65 nm depending on the experimental conditions used. The tribological properties of the base oil with the bismuth nanoparticles additives were evaluated using a four-ball tester. Tests were performed using the base oil with and without Bi nanoparticles. It was observed that the coefficient of friction of the oil decrease with an increasing concentration of the nanoparticles. The results also showed that the wear rate was reduced when the Bi nanoparticle additives were used
Formal treatment of some low-temperature properties of melting solid helium-3

International Nuclear Information System (INIS)

Goldstein, L.

1979-01-01

Recent observations of the low-field-strength paramagnetic susceptibility of melting solid 3 He indicate its Curie--Weiss-type behavior at temperatures T> or approx. =5 mK. These require an identical temperature behavior of the magnetic melting-pressure shift over the same temperature range. Melting-pressure-shift measurements should thus independently confirm the observed temperature behavior of the susceptibility and yield, in addition, the curie constant of melting solid 3 He. Using the theoretical value of this constant in the low- or moderate-field-strength melting-pressure-shift formula, the calculated shifts appear to be currently accessible to measurements with acceptable accuracy at T> or approx. =5 mK. The inverse problem of determination of the paramagnetic moment or magnetization of melting solid 3 He from melting-pressure shifts may be solved on the basis of a differential magnetothermodynamic relation without significant limitations on the applied external magnetic field strength or on the temperature range. Helium-3 melting-pressure and temperature measurements in the presence of a constant and uniform magnetic field of known strength should enable, within the above formalism, the determination of the magnetic phase diagram of solid 3 He at melting down to the lowest experimentally accessible temperatures. This approach may supplement other independent methods of magnetic phase-boundary-line determinations of solid 3 He
Determination of temperature dependant viscosity values of lubricants via simultaneous measurements of refractive index

International Nuclear Information System (INIS)

Yaltkaya, S.

2005-01-01

Viscosity is one of the most important parameter in rheological and tribological properties of fluids. The objective of this study is to obtain the viscosity values from the simultaneous refractive-index measurements of lubricants, simply by dipping the fiber-optic probe into the oil to be measured. Due to the fact that these parameters are temperature dependent, within the interval under consideration, oil heated up steadily while measuring the viscosity and refractive index at the same time. The refractive index sensor, the digital viscometer and the thermometer were connected to a PC via an analog to digital converter and the values were acquired at the same time. The fiber optic refractive index sensor has been designed in our laboratory. By utilising Fresnel's fundamental reflection law, the intensity of reflected light from boundary surface (optic fiber core-motor oil) was measured at 660 nm wavelength and then refractive index of the oil was calculated. The derived refractive index values were converted viscosity values that acquired by using the calibration equation. The viscometer, used during the study, was the rotational Brookfield type
Role of water lubricated bearings in Candu reactors

International Nuclear Information System (INIS)

Kumar, Ashok N.

1999-01-01

During the twentieth century a great emphasis was placed in understanding and defining the operating regime of oil and grease lubricated components. Major advances have been made through elastohydrodynamic lubrication theory in the quantifying the design life of heavily loaded components such as rolling element bearings and gears. Detailed guidelines for the design of oil and grease lubricated components are widely available and are being applied to the successful design of these components. However similar guidelines for water lubricated components are either not available or not well documented. It is often forgotten that the water was used as a lubricant in several components as far back as 1884 B.C. During the twentieth century the water lubricated components continued to play a major role in some high technology industries such as in the power generation plants. In CANDU nuclear reactors water lubrication of several critical components always occupied a pride place and in most cases the only practical mode of lubrication of several critical components always occupied a pride place and in most cases the only practical mode of lubrication. This paper presents some examples of the major water lubricated components in a CANDU reactors. Major part of the paper is focused on presenting an example of successful operating history of water lubricated bearings used in the HT pumps are presented. Both types of bearings have been qualified by tests for operation under normal as well as under more severe postulated condition of loss-of-coolant-accident (LOCA). These bearings have been designed to operate for the 30 years in the existing CANDU 6 (600 MW) reactors. However for the next generation of CANDU 6 reactors which go into service in the year 2003, the HT pump bearing life has been extended to 40 years. (author)
Lubricant Test Methods for Sheet Metal Forming

DEFF Research Database (Denmark)

Bay, Niels; Olsson, David Dam; Andreasen, Jan Lasson

2008-01-01

appearing in different sheet forming operations such as stretch forming, deep drawing, ironing and punching. The laboratory tests have been especially designed to model the conditions in industrial production. Application of the tests for evaluating new lubricants before introducing them in production has......Sheet metal forming of tribologically difficult materials such as stainless steel, Al-alloys and Ti-alloys or forming in tribologically difficult operations like ironing, punching or deep drawing of thick plate requires often use of environmentally hazardous lubricants such as chlorinated paraffin...... oils in order to avoid galling. The present paper describes a systematic research in the development of new, environmentally harmless lubricants focusing on the lubricant testing aspects. A system of laboratory tests has been developed to study the lubricant performance under the very varied conditions...
Film Thickness and Friction Relationship in Grease Lubricated Rough Contacts

Directory of Open Access Journals (Sweden)

David Gonçalves

2017-08-01

Full Text Available The relationship between the film generation and the coefficient of friction in grease lubricated contacts was investigated. Ball-on-disc tests were performed under different operating conditions: entrainment speed, lubricant temperature and surface roughness. The tests were performed with fully formulated greases and their base oils. The greases were formulated with different thickener types and also different base oils natures and viscosities. Film thickness measurements were performed in ball-on-glass disc tests, and Stribeck curves were measured in ball-on-steel disc tests with discs of different roughness. The role of the thickener and the base oil nature/viscosity on the film thickness and coefficient of friction was addressed and the greases’ performance was compared based on their formulation.
Materials for high temperature solid oxide fuel cells

International Nuclear Information System (INIS)

Singhal, S.C.

1987-01-01

High temperature solid oxide fuel cells show great promise for economical production of electricity. These cells are based upon the ability of stabilized zirconia to operate as an oxygen ion conductor at elevated temperatures. The design of the tubular solid oxide fuel cell being pursued at Westinghouse is illustrated. The cell uses a calcia-stabilized zironcia porous support tube, which acts both as a structural member onto which the other cell components are fabricated in the form of thin layers, and as a functional member to allow the passage, via its porosity, of air (or oxygen) to the air electrode. This paper summarizes the materials and fabrication processes for the various cell components
Determinan Kepuasan Pelanggan Pada Produk Pertamina Lubricants

Directory of Open Access Journals (Sweden)

Berto Mulia Wibawa

2017-02-01

Full Text Available Determinants of Customer Satisfaction at Pertamina's Lubricants ProductLubricant industry is one of the strategic industries in around the world. The potential of the lubricant industry in Indonesia grows rapidly along with the increasing demand and the number of a vehicle from year to year. This study aims to analyze factors that influencing customer satisfaction Pertamina Lubricants product and measure how far the customer satisfaction level of its product. This study observed eight categories of Pertamina Lubricants product, with quota sampling technique where each category of the product taken 30 samples, so the total number of the sample are 240 respondents. Multiple linear regression and customer satisfaction index were used in this study. The study finds brand popularity has the most significant effect on customer satisfaction, followed by price and durability. Customer satisfaction level stands at 78 percent, which means belongs in the satisfied category. Managerial implications of this study provide strategies for Pertamina Lubricants to improve their business performance and to increase the level of customer satisfactionDOI: 10.15408/ess.v7i1.4309
Deviation from van’t Hoff Behavior of Solids at Low Temperature

NARCIS (Netherlands)

Sluyters, Jan H.; Sluyters-rehbach, Margaretha

2017-01-01

As a sequel to results obtained on the low-temperature behavior of liquids, a similar study is presented for solids. A molecule in a solid interacts with the other molecules of the crystal so that it is subjected to a specific multimolecular potential, kT0. At temperature T < T0, the molecules are
Process for the preparation of lubricants

Energy Technology Data Exchange (ETDEWEB)

Pier, M

1927-06-04

A process is described for preparation of lubricants from mixtures of hydrocarbons or hydrocarbon derivatives of mean molecular weight and nonaromatic nature, which is characterized by halogenating the raw oil by the action of halogens or halogen-exchanging compounds and submitting the obtained product to a condensation in presence of aluminum chloride, tin chloride, iron chloride, or other condensing metal chloride or boron fluoride or activated metals, such as activated aluminum, whereby it is worked up in two steps at a temperature below 150 and preferably below 100/sup 0/C.
Application of Terahertz Attenuated Total Reflection Spectroscopy to Detect Changes in the Physical Properties of Lactose during the Lubrication Process Required for Drug Formulation.

Science.gov (United States)

Dohi, Masafumi; Momose, Wataru; Yamashita, Kazunari; Hakomori, Tadashi; Sato, Shusaku; Noguchi, Shuji; Terada, Katsuhide

2017-02-01

Manufacturing the solid dosage form of an orally administered drug requires lubrication to enhance manufacturability, ensuring that critical quality attributes such as disintegration and dissolution of the drug product are maintained during manufacture. Here, to evaluate lubrication performance during manufacture, we used terahertz attenuated total reflection (THz-ATR) spectroscopy to detect differences in the physical characteristics of the lubricated powder. We applied a simple formulation prepared by blending granulated lactose as filler with magnesium stearate as lubricant. A flat tablet was prepared using the lubricated powder to acquire sharp THz-ATR absorption peaks of the samples. First, we investigated the effects of lubricant concentration and compression pressure on preparation of the tablet and then determined the effect of the pressure applied to samples in contact with the ATR prism on sample absorption amplitude. We focused on the differences in the magnitudes of spectra at the lactose-specific frequency. Second, we conducted the dynamic lubrication process using a 120-L mixer to investigate differences in the magnitudes of absorption corresponding to the lactose-specific frequency during lubrication. In both studies, enriching the lubricated powder with a higher concentration of magnesium stearate or prolonging blending time correlated with higher magnitudes of spectra at the lactose-specific frequency. Further, in the dynamic lubrication study, the wettability and disintegration time of the tablets were compared with the absorption spectra amplitudes at the lactose-specific frequency. We conclude that THz-ATR spectroscopy is useful for detecting differences in densities caused by a change in the physical properties of lactose during lubrication.
Application of a Biodegradable Lubricant in a Diesel Vehicle

DEFF Research Database (Denmark)

Schramm, Jesper

2003-01-01

, NOx, THC, PM, lubricant-SOF and PAH from one diesel and one gasoline type vehicle using biodegradable lubricants and conventional lubricants. This paper describes the results of the experiments with the diesel type vehicle only. Lubricant consumption and fuel consumption are other important parameters...

Low temperature kinetics of In-Cd solid solution decomposition

Czech Academy of Sciences Publication Activity Database

Pal-Val, P.P.; Pal-Val, L.N.; Ostapovets, A.A.; Vaněk, Přemysl

2008-01-01

Roč. 137, - (2008), s. 35-42 ISSN 1012-0394 Institutional research plan: CEZ:AV0Z10100520 Keywords : low temperatures * In-based alloys * solid solutions * isothermal structure instability * Young's modulus * electrical resistivity * phase diagrams Subject RIV: BM - Solid Matter Physics ; Magnetism http://www.scientific.net/3-908451-53-1/35/
Low temperature ozone oxidation of solid waste surrogates

Science.gov (United States)

Nabity, James A.; Lee, Jeffrey M.

2015-09-01

Solid waste management presents a significant challenge to human spaceflight and especially, long-term missions beyond Earth orbit. A six-month mission will generate over 300 kg of solid wastes per crewmember that must be dealt with to eliminate the need for storage and prevent it from becoming a biological hazard to the crew. There are several methods for the treatment of wastes that include oxidation via ozone, incineration, microbial oxidation or pyrolysis and physical methods such as microwave drying and compaction. In recent years, a low temperature oxidation process using ozonated water has been developed for the chemical conversion of organic wastes to CO2 and H2O. Experiments were conducted to evaluate the rate and effectiveness with which ozone oxidized several different waste materials. Increasing the surface area by chopping or shredding the solids into small pieces more than doubled the rate of oxidation. A greater flow of ozone and agitation of the ozonated water system also increased processing rates. Of the materials investigated, plastics have proven the most difficult to oxidize. The processing of plastics above the glass transition temperatures caused the plastics to clump together which reduced the exposed surface area, while processing at lower temperatures reduced surface reaction kinetics.
Screening the performance of lubricants for ironing of stainless steel with a strip reduction test

DEFF Research Database (Denmark)

Andreasen, Jan Lasson; Bay, Niels; Andersen, Mette Merete

1997-01-01

A laboratory strip reduction test simulating the tribological conditions of an ironing process is proposed. The test is capable of simulating varying process conditions such as reduction, drawing speed, tool temperature and sliding length. The test makes it possible to quantify the onset of break...... of breakdown of the lubricant film and subsequent galling. Experimental investigations of stainless steel show the influence of varying process conditions and the performance of different lubricants.......A laboratory strip reduction test simulating the tribological conditions of an ironing process is proposed. The test is capable of simulating varying process conditions such as reduction, drawing speed, tool temperature and sliding length. The test makes it possible to quantify the onset...
An experimental assessment on the performance of different lubrication techniques in grinding of Inconel 751.

Science.gov (United States)

Balan, A S S; Vijayaraghavan, L; Krishnamurthy, R; Kuppan, P; Oyyaravelu, R

2016-09-01

The application of emulsion for combined heat extraction and lubrication requires continuous monitoring of the quality of emulsion to sustain a desired grinding environment; this is applicable to other grinding fluids as well. Thus to sustain a controlled grinding environment, it is necessary to adopt an effectively lubricated wheel-work interface. The current study was undertaken to assess experimentally the effects of different grinding environments such as dry, minimum quantity lubrication (MQL) and Cryo-MQL on performance, such as grinding force, temperature, surface roughness and chip morphology on Inconel 751, a higher heat resistance material posing thermal problems and wheel loading. The results show that grinding with the combination of both liquid nitrogen (LN2) and MQL lowers temperature, cutting forces, and surface roughness as compared with MQL and dry grinding. Specific cutting energy is widely used as an inverse measure of process efficiency in machining. It is found from the results that specific cutting energy of Cryo-MQL assisted grinding is 50-65% lower than conventional dry grinding. The grindability of Inconel 751 superalloy can be enhanced with Cryo-MQL condition.
Recovery of very viscous lubricating oils from shale-tar, etc

Energy Technology Data Exchange (ETDEWEB)

Erdmann, E

1919-09-10

Modification of the process covered by German Patent 335,190 for recovering very viscous lubricating oils, consisting, in place of brown-coal tar, deparafinned peat tar being subjected to the treatment with superheated steam from about 200 to 250/sup 0/C or to heating in vacuum at a temperature below 250/sup 0/C.
Two methodologies for optical analysis of contaminated engine lubricants

International Nuclear Information System (INIS)

Aghayan, Hamid; Yang, Jun; Bordatchev, Evgueni

2012-01-01

The performance, efficiency and lifetime of modern combustion engines significantly depend on the quality of the engine lubricants. However, contaminants, such as gasoline, moisture, coolant and wear particles, reduce the life of engine mechanical components and lubricant quality. Therefore, direct and indirect measurements of engine lubricant properties, such as physical-mechanical, electro-magnetic, chemical and optical properties, are intensively utilized in engine condition monitoring systems and sensors developed within the last decade. Such sensors for the measurement of engine lubricant properties can be used to detect a functional limit of the in-use lubricant, increase drain interval and reduce the environmental impact. This paper proposes two new methodologies for the quantitative and qualitative analysis of the presence of contaminants in the engine lubricants. The methodologies are based on optical analysis of the distortion effect when an object image is obtained through a thin random optical medium (e.g. engine lubricant). The novelty of the proposed methodologies is in the introduction of an object with a known periodic shape behind a thin film of the contaminated lubricant. In this case, an acquired image represents a combined lubricant–object optical appearance, where an a priori known periodic structure of the object is distorted by a contaminated lubricant. In the object shape-based optical analysis, several parameters of an acquired optical image, such as the gray scale intensity of lubricant and object, shape width at object and lubricant levels, object relative intensity and width non-uniformity coefficient are newly proposed. Variations in the contaminant concentration and use of different contaminants lead to the changes of these parameters measured on-line. In the statistical optical analysis methodology, statistical auto- and cross-characteristics (e.g. auto- and cross-correlation functions, auto- and cross-spectrums, transfer function
When you lubricate well, you go well? A cause analysis of damages on bearer rings at a hydrogen compressor recently brought into service with the aid of monitoring the lubricating points of cylinder liners; Wer gut schmiert, der gut faehrt? Ursachenanalyse an Tragringschaeden bei einem neu in Betrieb genommenen Wasserstoffverdichter mit Hilfe einer Zylinderschmierstellenueberwachung

Energy Technology Data Exchange (ETDEWEB)

Klinger, Lars [Bayernoil Raffineriegesellschaft mbH, Neustadt a.d. Donau (Germany)

2013-02-15

For humans the blood circuit transports the ''lifeblood''. It supplies the body with the different essential nutrients and disposes adverse waste. The circuit of lubricant in recip compressors has quiet similar functions. It provides all relevant components with lubricant. This lubricant circuit supplies i.a. the crosshead slide way and bearings, where a hydrodynamic flooding is created. At the same time frictional heat is conducted and pollutions as well as deposits are washed away. But especially for recip compressors there is also another lubricating system, which is barely applied in the real operating process. It is about the supply of the packing glands and the piston liners with lubricant inside the compression chamber at ''wet running machines''. In the case of the lubricant supply at cylinder liners the lubricating oil is dispatched to the appropriate areas by an external lubricating system, which consists of a reservoir and an oil pump. This is a loss lubrication, i.e. the used lubricate is transported into the process by the transfer medium. The mechanical quality of this lubricating system can have great influence on the durability of bearer rings and sealing rings in a recip compressor. Especially the homogeneity of the dispatched lubricating oil amount and the absolute dispatched amount are two very important factors. The absolute amount is within the range of cm{sup 3} per hour. The influences of the cylinder liner lubricant supply on the durability of piston seal rings and bearer rings are shown with the concrete example of one recip compressor. Analytical measures to clearly detect such damages at the bearer rings are disclosed, just as which possibility there is to measure the low quantity of lubricant to the cylinder liners reliably. Furthermore a solution is presented, which allows the solid operation of the compressor.
Performance of gas-lubricated cruciform-mounted tilting-pad journal bearings and a damped flexibly mounted spiral-groove thrust bearing

Science.gov (United States)

Ream, L. W.

1974-01-01

A test program was conducted to determine the performance characteristics of gas-lubricated cruciform-mounted tilting-pad journal bearings and a damped spiral-groove thrust bearing designed for the Brayton cycle rotating unit (BRU). Hydrostatic, hybrid (simultaneously hydrostatic and hydrodynamic), and hydrodynamic tests were conducted in argon gas at ambient pressure and temperature ranges representative of operation to the 10.5 kWe BRU power-generating level. Performance of the gas lubricated bearings is presented including hydrostatic gas flow rates, bearing clearances, bearing temperatures, and transient performance.
Are Ionic Liquids Good Boundary Lubricants? A Molecular Perspective

Directory of Open Access Journals (Sweden)

Romain Lhermerout

2018-01-01

Full Text Available The application of ionic liquids as lubricants has attracted substantial interest over the past decade and this has produced a rich literature. The aim of this review is to summarize the main findings about frictional behavior of ionic liquids in the boundary lubrication regime. We first recall why the unusual properties of ionic liquids make them very promising lubricants, and the molecular mechanisms at the origin of their lubricating behavior. We then point out the main challenges to be overcome in order to optimise ionic liquid lubricant performance for common applications. We finally discuss their use in the context of electroactive lubrication.
Compatibility of lubricant additives with HFC refrigerants and synthetic lubricants. Final report, Part 1

Energy Technology Data Exchange (ETDEWEB)

Cavestri, R.C. [Imagination Resources, Inc., Dublin, OH (United States)

1997-07-01

Part one of this research provides manufacturers of components of air-conditioning and refrigeration equipment with a useful list of lubricant additives, sources, functional properties and chemical species. The list in part one is comprised of domestic lubricant additive suppliers and the results of a literature search that was specifically targeted for additives reported to be useful in polyolester chemistry.
A new lubricant carrier for metal forming

DEFF Research Database (Denmark)

Arentoft, Mogens; Bay, Niels; Tang, Peter Torben

2009-01-01

A lubricant carrier for metal forming processes is developed. Surfaces with pores of micrometer size for entrapping lubricant are generated by electrochemical deposition of an alloy, consisting of two immiscible metals, of which one metal subsequently is etched away leaving 5 mu m layers with a s...... extrusion at high reduction and excessive stroke comparing with conventionally lubrication using phosphate coating and soap....
New diffusion mechanism for high temperature diffusion in solids

International Nuclear Information System (INIS)

Doan, N.V.; Adda, Y.

1986-09-01

A new atomic transport mechanism in solids at high temperatures has been discovered by Molecular Dynamics computer simulation. It can be described as a ring sequence of atomic replacements induced by unstable Frenkel pairs. This transport process takes place without stable defects, the atomic migration occurring indeed by simultaneous creation and migration of unstable defects. Starting from the analysis of this mechanism in different solids at high temperature (CaF 2 , Na, Ar) and in irradiated copper by subthreshold collisions, we discuss the role of this mechanism on various diffusion controlled phenomena and also on the atomic processes of defect creation
New Lubricants Protect Machines and the Environment

Science.gov (United States)

2007-01-01

In 1994, NASA and Lockheed Martin Space Operations commissioned Sun Coast Chemicals of Daytona Inc to develop a new type of lubricant that would be safe for the environment and help "grease the wheels" of the shuttle-bearing launcher platform. Founded in 1989, Sun Coast Chemicals is known amongst the racing circuit for effective lubricants that help overcome engine and transmission problems related to heat and wear damage. In a matter of weeks, Sun Coast Chemical produced the biodegradable, high-performance X-1R Crawler Track Lube. In 1996, Sun Coast Chemical determined there was a market for this new development, and introduced three derivative products, Train Track Lubricant, Penetrating Spray Lubricant, and Biodegradable Hydraulic Fluid, and then quickly followed with a gun lubricant/cleaner and a fishing rod and reel lubricant. Just recently, Sun Coast introduced the X-1R Corporation, which folds the high-performance, environmentally safe benefits into a full line of standard automotive and specially formulated racing products. The entire X-1R automotive product line has stood up to rigorous testing by groups such as the American Society of Mechanical Engineers, the Swedish National Testing and Research Institute, the Department of Mechanical Engineering at Oakland University (Rochester, Michigan), and Morgan-McClure Motorsports (Abingdon, Virginia). The X-1R Corporation also markets "handy packs" for simple jobs around the house, consisting of a multi-purpose, multi-use lubricant and grease. In 2003, The X-1R Corporation teamed up with Philadelphia-based Penn Tackle Manufacturing Co., a leading manufacturer of fishing tackle since 1932, to jointly develop and market a line of advanced lubrication products for saltwater and freshwater anglers
Performance test of diamond-like carbon films for lubricating ITER blanket maintenance equipment under GPa-level high contact stress

International Nuclear Information System (INIS)

Takeda, Nobukazu; Kakudate, Satoshi; Nakahira, Masataka; Shibanuma, Kiyoshi

2007-01-01

Diamond-like carbon (DLC) coating was tested as a candidate solid lubricant for transmission gears of the maintenance equipment of the blanket of the ITER instead of an oil lubricant. The wear tests using the pin-on-disk method were performed on disks with SCM440 and SNCM420 as the base materials and coated with soft, layered, and hard DLCs. All cases satisfied the required allowable contact stress (2 GPa) and lifetime (10 4 cycles), and therefore the feasibility of the DLC coating was validated. Among the three types of DLCs, the soft DLC showed the best performance. (author)
Collaborative Lubricating Oil Study on Emissions: November 28, 2006 - March 31, 2011

Energy Technology Data Exchange (ETDEWEB)

Carroll, J. N.; Khalek, I. A.; Smith, L. R.; Fujita, E.; Zielinska, B.

2011-10-01

The Collaborative Lubricating Oil Study on Emissions (CLOSE) project was a pilot investigation of how fuels and crankcase lubricants contribute to the formation of particulate matter (PM) and semi-volatile organic compounds (SVOC) in vehicle exhaust. As limited vehicles were tested, results are not representative of the whole on-road fleet. Long-term effects were not investigated. Pairs of vehicles (one normal PM emitting, one high-PM emitting) from four categories were selected: light-duty (LD) gasoline cars, medium-duty (MD) diesel trucks, heavy-duty (HD) natural-gas-fueled buses, and HD diesel buses. HD vehicles procured did not exhibit higher PM emissions, and thus were labeled high mileage (HM). Fuels evaluated were non-ethanol gasoline (E0), 10 percent ethanol (E10), conventional low-sulfur TxLED diesel, 20% biodiesel (B20), and natural gas. Temperature effects (20 degrees F, 72 degrees F) were evaluated on LD and MD vehicles. Lubricating oil vintage effects (fresh and aged) were evaluated on all vehicles. LD and MD vehicles were operated on a dynamometer over the California Unified Driving Cycle, while HD vehicles followed the Heavy Duty Urban Dynamometer Driving Schedule. Regulated and unregulated emissions were measured. Chemical markers from the unregulated emissions measurements and a tracer were utilized to estimate the lubricant contribution to PM.
FY2014 Fuel & Lubricant Technologies Annual Progress Report

Energy Technology Data Exchange (ETDEWEB)

Stork, Kevin [Office of Energy Efficiency and Renewable Energy (EERE), Washington, DC (United States)

2016-02-01

Annual progress report for Fuel & Lubricant Technologies. The Fuel & Lubricant Technologies Program supports fuels and lubricants research and development (R&D) to provide vehicle manufacturers and users with cost-competitive options that enable high fuel economy with low emissions, and contribute to petroleum displacement.
Management of industrial solid residues; Gerenciamento de residuos solidos industriais

Energy Technology Data Exchange (ETDEWEB)

NONE

2002-07-01

This chapter gives an overview on the management of industrial solid wastes, approaching the following subjects: classification of industrial solid residues; directives and methodologies for the management of industrial solid residues; instruments for the management of industrial solid residues; handling, packing, storage and transportation; treatment of industrial solid residues; final disposal - landfill for industrial residues; the problem of treatment and final disposer of domestic garbage in Brazil; recycling of the lubricant oils used in brazil; legislation.
One of possible variants of the organization for recycling lubricate cooling of technological means for small businesses

Science.gov (United States)

Rusica, I.; Toca, A.; Stingaci, I.; Scaticailov, S.; Scaticailov, I.; Marinescu, O.; Kosenko, P.

2016-11-01

In the paper we analyze the application lubricate cooling technological environment in the processing of various materials in the past century greatly have increased cutting speed and respectively, has increased productivity [1]. Today, none of production in which anyway is used metal cutting machines of all types (milling, turning, grinding, drilling, etc.) is not without lubricant cooling technological liquid which in turn are designed to reduce cutting force and the load on metal cutting machine tools and machined parts in order to increase durability machine tools and reduce errors of processing details and also in resource energy saving. When using lubricate cooling technological environment reduces the temperature in the cutting zone resulting in higher tool life and the preservation of the surface structure being treated reducing wear of metal parts of the machine. Typically, lubricant cooling process fluids is used without replacing as long as possible not yet beginning to negatively affect the quality of process. However life expectancy lubricate cooling technological environment is limited. According to existing normative acts every kind of lubricate cooling technological environment through certain time must be deleted by from the system and subjected to a recycling. Lubricate cooling technological environment must be disposed of for the following reasons: occurs the microbial and the mechanical pollution cutting fluid, free oil impairs operational characteristics cutting fluid and increases consumption.
Effect of surface finishing on friction and wear of Poly-Ether-Ether-Ketone (PEEK under oil lubrication

Directory of Open Access Journals (Sweden)

Thiago Fontoura de Andrade

Full Text Available Abstract The tribological properties of poly-ether-ether-ketone (PEEK containing 30% of carbon fiber were studied in an oil-lubricated environment and different surface finishing of the metallic counterbody. Four different finishing processes, commonly used in the automotive industry, were chosen for this study: turning, grinding, honing and polishing. The test system used was tri-pin on disc with pins made of PEEK and counterbody made of steel; they were fully immersed in ATF Dexron VI oil. Some test parameters were held constant, such as the apparent pressure of 2 MPa, linear velocity of 2 m/s, oil temperature at 85 °C, and the time - 120 minutes. The lubrication regime for the apparent pressure of 1 MPa to 7 MPa range was also studied at different sliding speeds. A direct correlation was found between the wear rate, friction coefficient and the lubrication regime, wherein wear under hydrodynamic lubrication was, on average, approximately 5 times lower, and the friction coefficient 3 times lower than under boundary lubrication.
Compatibility of manufacturing process fluids with R-134a and polyolester lubricant. Final report

Energy Technology Data Exchange (ETDEWEB)

Cavestri, R.C.; Schooley, D.L. [Imagination Resources, Inc., Dublin, OH (United States)

1996-07-01

This report includes a broad list of processing fluids that are known to be used to manufacture air conditioning and refrigeration products. Sixty-four process fluids from this list were selected for compatibility studies with R-134a and ICI EMKARATE RL32H (32 ISO) polyolester lubricant. Solutions or suspensions of the process fluid residues in polyolester lubricant were heated for 14 days at 175{degrees}C (347{degrees}F) in evacuated sealed glass tubes containing only valve steel coupons. Miscibility tests were performed at 90 wt.% R-134a, 10 wt.% polyolester lubricant with process fluid residue contaminate and were scanned in 10{degrees}C (18{degrees}F) increments over a temperature range of ambient to -40{degrees}C (-40{degrees}F). Any sign of turbidity, haze formation or oil separation was considered the immiscibility point.

Lubricant effects on low Dk and silicone hydrogel lens comfort.

Science.gov (United States)

Ozkan, Jerome; Papas, Eric

2008-08-01

To investigate the influence of three lubricants of varying viscosity, on postinsertion and 6 h comfort with contact lens wear. Comfort and associated symptoms of dryness were assessed in 15 experienced contact lens wearers. Subjects wore a low Dk lens in one eye and a silicone hydrogel in the other and participated in four separate trials involving no lubricant (baseline), saline, and two commercially available lubricants of differing viscosity. The in-eye lubricants were used immediately following lens insertion and every 2 h postinsertion for a 6 h wear period. Postlens insertion comfort was significantly better for both lens types when lubricants or saline were used compared with no lubricant use. After 6 h lens wear, comfort was influenced by lens type and not by in-eye lubricant or saline use. Also after 6 h lens wear, less dryness sensation was reported for silicone hydrogel lenses when using lubricants but not saline. Although lubricant use does help reduce dryness symptoms with silicone hydrogel lens wear, there appears to be minimal longer-term benefit to comfort. Furthermore, increased lubricant viscosity did not lead to improved longer-term comfort.
Strategies for Lowering Solid Oxide Fuel Cells Operating Temperature

Directory of Open Access Journals (Sweden)

Albert Tarancón

2009-11-01

Full Text Available Lowering the operating temperature of solid oxide fuel cells (SOFCs to the intermediate range (500–700 ºC has become one of the main SOFC research goals. High operating temperatures put numerous requirements on materials selection and on secondary units, limiting the commercial development of SOFCs. The present review first focuses on the main effects of reducing the operating temperature in terms of materials stability, thermo-mechanical mismatch, thermal management and efficiency. After a brief survey of the state-of-the-art materials for SOFCs, attention is focused on emerging oxide-ionic conductors with high conductivity in the intermediate range of temperatures with an introductory section on materials technology for reducing the electrolyte thickness. Finally, recent advances in cathode materials based on layered mixed ionic-electronic conductors are highlighted because the decreasing temperature converts the cathode into the major source of electrical losses for the whole SOFC system. It is concluded that the introduction of alternative materials that would enable solid oxide fuel cells to operate in the intermediate range of temperatures would have a major impact on the commercialization of fuel cell technology.
Biodegradable lubricants - ''the solution for future?''

International Nuclear Information System (INIS)

Jahan, A.

1997-01-01

The environmental impact of lubricants use concern the direct effects from spills but also the indirect effects such as their lifetime and the emissions from thermal engines. The biodegradable performances and the toxicity are the environmental criteria that must be taken into account in the development and application of lubricants together with their technical performances. This paper recalls first the definition of biodegradable properties of hydrocarbons and the standardized tests, in particular the CEC and AFNOR tests. Then, the biodegradable performances of basic oils (mineral, vegetal, synthetic esters, synthetic hydrocarbons etc..), finite lubricants (hydraulic fluids..) and engine oils is analyzed according to these tests. Finally, the definition of future standards would take into account all the environmental characteristics of the lubricant: biodegradable performances, energy balance (CO 2 , NOx and Hx emissions and fuel savings), eco-toxicity and technical performances (wearing and cleanliness). (J.S.)
Functional regulation of Pb-Ti/MoS_2 composite coatings for environmentally adaptive solid lubrication

International Nuclear Information System (INIS)

Ren, Siming; Li, Hao; Cui, Mingjun; Wang, Liping; Pu, Jibin

2017-01-01

Highlights: • Co-doped Pb-Ti/MoS_2 composite coatings were successfully fabricated by unbalanced magnetron sputtering system. • Co-doped Pb-Ti/MoS_2 composite coatings showed lower friction coefficient and longer wear life in both humid and vacuum environments than that of single-doped ones. • The wear behaviours of Pb-Ti/MoS_2 composite coatings with the increase of Pb content is in accordance with the variation in H/E ratio that higher H/E is corresponding to the lower wear rate of coating. - Abstract: The lubrication of molybdenum disulfide coatings has commonly been limited by the application environments, for instance, the crystal MoS_2 are easily affected by water to form MoO_3 that causes a higher friction coefficient and short lifetime. Therefore, to improve the tribolgical performance of MoS_2 in high humidity condition, the co-doped Pb-Ti/MoS_2 composite coatings are deposited by unbalanced magnetron sputtering system. The design of the co-doping elements in MoS_2-based coatings can not only maintain the characteristic of low humidity-sensitivity as the Ti/MoS_2 coating but also improve the mechanical properties and tribological performance of coatings as a comparison with single-doped ones. Moreover, the ultra-low friction coefficient with a minimum value of 0.006 under the vacuum condition is achieved for Pb-Ti/MoS_2 composite coating containing about 4.6 at.% Pb, depending on the densification structure of coating. Intriguingly, the wear behaviours of Pb-Ti/MoS_2 composite coatings are in accordance with the variation in H/E (hardness to the elastic modulus) ratio that the coating with higher H/E exhibits lower wear rate. These results demonstrate that the lubricating properties of MoS_2 coatings in both humid environment and vacuum condition can be achieved through the Pb and Ti co-doped, which is of great significant for developing MoS_2 coatings as the environmentally adaptive lubricants.
The use of screening tests in spacecraft lubricant evaluation

Science.gov (United States)

Kalogeras, Chris; Hilton, Mike; Carre, David; Didziulis, Stephen; Fleischauer, Paul

1993-01-01

A lubricant screening test fixture has been devised in order to satisfy the need to obtain lubricant performance data in a timely manner. This fixture has been used to perform short-term tests on potential lubricants for several spacecraft applications. The results of these tests have saved time by producing qualitative performance rankings of lubricant selections prior to life testing. To date, this test fixture has been used to test lubricants for 3 particular applications. The qualitative results from these tests have been verified by life test results and have provided insight into the function of various anti-wear additives.
A study of mechanisms of liquid lubrication in metal forming

DEFF Research Database (Denmark)

Bech, Jakob Ilsted; Bay, Niels; Eriksen, Morten

1998-01-01

Applying a transparent tool technique the lubrication in plane strip drawing of aluminium sheet is studied providing the strip with surface pockets for entrapment of lubricant. The compression and eventual escape of trapped lubricant by Micro Plasto HydroDynamic Lubrication (MPHDL) as well as Micro...
Enhanced Biodegradability, Lubricity and Corrosiveness of Lubricating Oil by Oleic Acid Diethanolamide Phosphate

Directory of Open Access Journals (Sweden)

Fang Jianhua

2012-09-01

Full Text Available Impacts of oleic acid diethanolamide phosphate (abbreviated as ODAP as an additive on biodegradability, anti-wear capacity, friction-reducing ability and corrosiveness of an unreadily biodegradable HVI 350 mineral lubricating oil was studied. The biodegradabilities of neat lubricating oil and its formulations with ODAP were evaluated on a biodegradation tester. Furthermore, the anti-wear and friction-reducing abilities and the corrosiveness of neat oil and the formulated oils were determined on a four-ball tribotester and a copper strip corrosion tester, respectively. The results indicated that ODAP markedly enhanced biodegradability as well as anti-wear and friction-reducing abilities of the lubricating oil. On the other hand, excellent color ratings of copper strips for both neat oil and the ODAP-doped oil were obtained in the corrosion tests, demonstrating that the corrosiveness of neat oil and the doped oil was negligible, although the latter seemed to provide slightly better anti-corrosion ability.
Strip reduction testing of lubricants developed during ENFORM project

DEFF Research Database (Denmark)

Gazvoda, S.; Andreasen, Jan Lasson; Olsson, David Dam

Strip reduction testing of lubricants developed during ENFORM project. Experiments were conducted with the strip reduction test [1] in order to classify experimental lubricants, developed during concerned project. One reference lubricant was used during testing....
Solid-solid phase transformation via internal stress-induced virtual melting, significantly below the melting temperature. Application to HMX energetic crystal.

Science.gov (United States)

Levitas, Valery I; Henson, Bryan F; Smilowitz, Laura B; Asay, Blaine W

2006-05-25

We theoretically predict a new phenomenon, namely, that a solid-solid phase transformation (PT) with a large transformation strain can occur via internal stress-induced virtual melting along the interface at temperatures significantly (more than 100 K) below the melting temperature. We show that the energy of elastic stresses, induced by transformation strain, increases the driving force for melting and reduces the melting temperature. Immediately after melting, stresses relax and the unstable melt solidifies. Fast solidification in a thin layer leads to nanoscale cracking which does not affect the thermodynamics or kinetics of the solid-solid transformation. Thus, virtual melting represents a new mechanism of solid-solid PT, stress relaxation, and loss of coherence at a moving solid-solid interface. It also removes the athermal interface friction and deletes the thermomechanical memory of preceding cycles of the direct-reverse transformation. It is also found that nonhydrostatic compressive internal stresses promote melting in contrast to hydrostatic pressure. Sixteen theoretical predictions are in qualitative and quantitative agreement with experiments conducted on the PTs in the energetic crystal HMX. In particular, (a) the energy of internal stresses is sufficient to reduce the melting temperature from 551 to 430 K for the delta phase during the beta --> delta PT and from 520 to 400 K for the beta phase during the delta --> beta PT; (b) predicted activation energies for direct and reverse PTs coincide with corresponding melting energies of the beta and delta phases and with the experimental values; (c) the temperature dependence of the rate constant is determined by the heat of fusion, for both direct and reverse PTs; results b and c are obtained both for overall kinetics and for interface propagation; (d) considerable nanocracking, homogeneously distributed in the transformed material, accompanies the PT, as predicted by theory; (e) the nanocracking does not
An experimental assessment on the performance of different lubrication techniques in grinding of Inconel 751

Directory of Open Access Journals (Sweden)

A.S.S. Balan

2016-09-01

Full Text Available The application of emulsion for combined heat extraction and lubrication requires continuous monitoring of the quality of emulsion to sustain a desired grinding environment; this is applicable to other grinding fluids as well. Thus to sustain a controlled grinding environment, it is necessary to adopt an effectively lubricated wheel-work interface. The current study was undertaken to assess experimentally the effects of different grinding environments such as dry, minimum quantity lubrication (MQL and Cryo-MQL on performance, such as grinding force, temperature, surface roughness and chip morphology on Inconel 751, a higher heat resistance material posing thermal problems and wheel loading. The results show that grinding with the combination of both liquid nitrogen (LN2 and MQL lowers temperature, cutting forces, and surface roughness as compared with MQL and dry grinding. Specific cutting energy is widely used as an inverse measure of process efficiency in machining. It is found from the results that specific cutting energy of Cryo-MQL assisted grinding is 50–65% lower than conventional dry grinding. The grindability of Inconel 751 superalloy can be enhanced with Cryo-MQL condition.
Tethered Lubricants for Small Systems

Energy Technology Data Exchange (ETDEWEB)

Lynden A. Archer

2006-01-09

The objective of this research project is two-fold. First, to fundamentally understand friction and relaxation dynamics of polymer chains near surfaces; and second, to develop novel self-lubricated substrates suitable for MEMS devices. During the three-year performance period of this study the PI and his students have shown using theory and experiments that systematic introduction of disorder into tethered lubricant coatings (e.g. by using self-assembled monolayer (SAM) mixtures or SAMs with nonlinear, branched architectures) can be used to significantly reduce the friction coefficient of a surface. They have also developed a simple procedure based on dielectric spectroscopy for quantifying the effect of surface disorder on molecular relaxation in lubricant coatings. Details of research accomplishments in each area of the project are described in the body of the report.
Lubrication of nuclear reactor components

International Nuclear Information System (INIS)

Wild, E.; Mack, K.J.

1978-01-01

Safe operation of liquid metal cooled nuclear reactors requires a knowledge of the tribological behaviour of contacting components at high temperatures with slow relative movement at high frictional loads in a chemically aggressive environment. Experiments have been performed on various material combinations in liquid sodium and argon. Because of the small sliding movements, hydrodynamic lubrication is not expected and thus surface finish is an important factor. Tests have been performed on brushed, ground and lapped surfaces. Among the material combinations tested a CrC-coating on a 1.4961 stainless steel substrate performed well. Friction coefficients of 0.35-0.5 in argon and 0.1-1.2 in liquid sodium were recorded. (author)
MEMS Lubrication by In-Situ Tribochemical Reactions From the Vapor Phase.

Energy Technology Data Exchange (ETDEWEB)

Dugger, Michael Thomas; Asay, David B.; Kim, Seong H.

2008-01-01

Vapor Phase Lubrication (VPL) of silicon surfaces with pentanol has been demonstrated. Two potential show stoppers with respect to application of this approach to real MEMS devices have been investigated. Water vapor was found to reduce the effectiveness of VPL with alcohol for a given alcohol concentration, but the basic reaction mechanism observed in water-free environments is still active, and devices operated much longer in mixed alcohol and water vapor environments than with chemisorbed monolayer lubricants alone. Complex MEMS gear trains were successfully lubricated with alcohol vapors, resulting in a factor of 104 improvement in operating life without failure. Complex devices could be made to fail if operated at much higher frequencies than previously used, and there is some evidence that the observed failure is due to accumulation of reaction products at deeply buried interfaces. However, if hypothetical reaction mechanisms involving heated surfaces are valid, then the failures observed at high frequency may not be relevant to operation at normal frequencies. Therefore, this work demonstrates that VPL is a viable approach for complex MEMS devices in conventional packages. Further study of the VPL reaction mechanisms are recommended so that the vapor composition may be optimized for low friction and for different substrate materials with potential application to conventionally fabricated, metal alloy parts in weapons systems. Reaction kinetics should be studied to define effective lubrication regimes as a function of the partial pressure of the vapor phase constituent, interfacial shear rate, substrate composition, and temperature.
Machine integrated optical measurement of honed surfaces in presence of cooling lubricant

International Nuclear Information System (INIS)

Schmitt, R; Koenig, N; Zheng, H

2011-01-01

The measurement of honed surfaces is one of the most important tasks in tribology. Although many established techniques exist for texture characterization, such as SEM, tactile stylus or white-light interferometry, none of them is suited for a machine integrated measurement. Harsh conditions such as the presence of cooling lubricant or vibrations prohibit the use of commercial sensors inside a honing machine. Instead, machined engine blocks need time-consuming cleaning and preparation while taken out of the production line for inspection. A full inspection of all produced parts is hardly possible this way. Within this paper, an approach for a machine-integrated measurement is presented, which makes use of optical sensors for texture profiling. The cooling lubricant here serves as immersion medium. The results of test measurements with a chromatic-confocal sensor and a fiber-optical low-coherence interferometer show the potential of both measuring principles for our approach. Cooling lubricant temperature and flow, scanning speed and measurement frequency have been varied in the tests. The sensor with best performance will later be chosen for machine integration.
Current-voltage characteristics of C70 solid near Meyer-Neldel temperature

Science.gov (United States)

Onishi, Koichi; Sezaimaru, Kouki; Nakashima, Fumihiro; Sun, Yong; Kirimoto, Kenta; Sakaino, Masamichi; Kanemitsu, Shigeru

2017-06-01

The current-voltage characteristics of the C70 solid with hexagonal closed-packed structures were measured in the temperature range of 250-450 K. The current-voltage characteristics can be described as a temporary expedient by a cubic polynomial of the voltage, i = a v 3 + b v 2 + c v + d . Moreover, the Meyer-Neldel temperature of the C70 solid was confirmed to be 310 K, at which a linear relationship between the current and voltage was observed. Also, at temperatures below the Meyer-Neldel temperature, the current increases with increasing voltage. On the other hand, at temperatures above the Meyer-Neldel temperature a negative differential conductivity effect was observed at high voltage side. The negative differential conductivity was related to the electric field and temperature effects on the mobility of charge carrier, which involve two variations in the carrier concentration and the activation energy for carrier hopping transport.
Tribological performance of nanoparticles as lubricating oil additives

International Nuclear Information System (INIS)

Gulzar, M.; Masjuki, H. H.; Kalam, M. A.; Varman, M.; Zulkifli, N. W. M.; Mufti, R. A.; Zahid, Rehan

2016-01-01

The prospect of modern tribology has been expanded with the advent of nanomaterial-based lubrication systems, whose development was facilitated by the nanotechnology in recent years. In literature, a variety of nanoparticles have been used as lubricant additives with potentially interesting friction and wear properties. To date, although there has been a great deal of experimental research on nanoparticles as lubricating oil additives, many aspects of their tribological behavior are yet to be fully understood. With growing number of possibilities, the key question is: what types of nanoparticles act as a better lubricating oil additive and why? To answer this question, this paper reviews main types of nanoparticles that have been used as lubricants additives and outlines the mechanisms by which they are currently believed to function. Significant aspects of their tribological behavior such as dispersion stability and morphology are also highlighted.
Tribological performance of nanoparticles as lubricating oil additives

Energy Technology Data Exchange (ETDEWEB)

Gulzar, M., E-mail: mubashir-nustian@hotmail.com; Masjuki, H. H., E-mail: masjuki@um.edu.my; Kalam, M. A.; Varman, M.; Zulkifli, N. W. M. [University of Malaya, Department of Mechanical Engineering, Faculty of Engineering, Centre for Energy Sciences (Malaysia); Mufti, R. A. [National University of Sciences and Technology (NUST) (Pakistan); Zahid, Rehan [University of Malaya, Department of Mechanical Engineering, Faculty of Engineering, Centre for Energy Sciences (Malaysia)

2016-08-15

The prospect of modern tribology has been expanded with the advent of nanomaterial-based lubrication systems, whose development was facilitated by the nanotechnology in recent years. In literature, a variety of nanoparticles have been used as lubricant additives with potentially interesting friction and wear properties. To date, although there has been a great deal of experimental research on nanoparticles as lubricating oil additives, many aspects of their tribological behavior are yet to be fully understood. With growing number of possibilities, the key question is: what types of nanoparticles act as a better lubricating oil additive and why? To answer this question, this paper reviews main types of nanoparticles that have been used as lubricants additives and outlines the mechanisms by which they are currently believed to function. Significant aspects of their tribological behavior such as dispersion stability and morphology are also highlighted.
Exposure of natural rubber to personal lubricants--swelling and stress relaxation as potential indicators of reduced seal integrity of non-lubricated male condoms.

Science.gov (United States)

Sarkar Das, Srilekha; Coburn, James C; Tack, Charles; Schwerin, Matthew R; Richardson, D Coleman

2014-07-01

Male condoms act as mechanical barriers to prevent passage of body fluids. For effective use of condoms the mechanical seal is also expected to remain intact under reasonable use conditions, including with personal lubricants. Absorption of low molecular weight lubricant components into the material of male condoms may initiate material changes leading to swelling and stress relaxation of the polymer network chains that could affect performance of the sealing function of the device. Swelling indicates both a rubber-solvent interaction and stress relaxation, the latter of which may indicate and/or result in a reduced seal pressure in the current context. Swelling and stress relaxation of natural rubber latex condoms were assessed in a laboratory model in the presence of silicone-, glycol-, and water-based lubricants. Within 15 minutes, significant swelling (≥6 %) and stress reduction (≥12 %) of condoms were observed with 2 out of 4 silicone-based lubricants tested, but neither was observed with glycol- or water-based lubricants tested. Under a given strain, reduction in stress was prominent during the swelling processes, but not after the process was complete. Lubricant induced swelling and stress relaxation may loosen the circumferential stress responsible for the mechanical seal. Swelling and stress relaxation behavior of latex condoms in the presence of personal lubricants may be useful tests to identify lubricant-rooted changes in condom-materials. For non-lubricated latex condoms, material characteristics--which are relevant to failure--may change in the presence of a few silicone-based personal lubricants. These changes may in turn induce a loss of condom seal during use, specifically at low strain conditions. Published by Elsevier Inc.
Friction and lubrication modelling in sheet metal forming: Influence of lubrication amount, tool roughness and sheet coating on product quality

Science.gov (United States)

Hol, J.; Wiebenga, J. H.; Carleer, B.

2017-09-01

In the stamping of automotive parts, friction and lubrication play a key role in achieving high quality products. In the development process of new automotive parts, it is therefore crucial to accurately account for these effects in sheet metal forming simulations. This paper presents a selection of results considering friction and lubrication modelling in sheet metal forming simulations of a front fender product. For varying lubrication conditions, the front fender can either show wrinkling or fractures. The front fender is modelled using different lubrication amounts, tool roughness’s and sheet coatings to show the strong influence of friction on both part quality and the overall production stability. For this purpose, the TriboForm software is used in combination with the AutoForm software. The results demonstrate that the TriboForm software enables the simulation of friction behaviour for varying lubrication conditions, i.e. resulting in a generally applicable approach for friction characterization under industrial sheet metal forming process conditions.
Hydrodynamic Lubrication

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 9. Hydrodynamic Lubrication Experiment with 'Floating' Drops. Jaywant H Arakeri K R Sreenivas. General Article Volume 1 Issue 9 September 1996 pp 51-58. Fulltext. Click here to view fulltext PDF. Permanent link:

Lubrication and cooling for high speed gears

Science.gov (United States)

Townsend, D. P.

1985-01-01

The problems and failures occurring with the operation of high speed gears are discussed. The gearing losses associated with high speed gearing such as tooth mesh friction, bearing friction, churning, and windage are discussed with various ways shown to help reduce these losses and thereby improve efficiency. Several different methods of oil jet lubrication for high speed gearing are given such as into mesh, out of mesh, and radial jet lubrication. The experiments and analytical results for the various methods of oil jet lubrication are shown with the strengths and weaknesses of each method discussed. The analytical and experimental results of gear lubrication and cooling at various test conditions are presented. These results show the very definite need of improved methods of gear cooling at high speed and high load conditions.
Single Common Powertrain Lubricant (SCPL) Development. Part 2

Science.gov (United States)

2014-04-01

Lubricant (SCPL), General Engine Products (GEP) 6.5L(T), Detroit Diesel Corporation ( DDC ) 6V53T, High Temperature Oil Endurance, MIL-PRF-46167, MIL-PRF...using the Detroit Diesel Corporation ( DDC ) 6V53T, American Society for Testing and Materials (ASTM) D5966 roller follower wear protection...candidates. A Detroit Diesel Corporation ( DDC ) 6V53T, from the M113A3 Armored Personnel Carrier (APC), was used to evaluate the two revised candidates and a
Lubricant reflow after laser heating in heat assisted magnetic recording

Science.gov (United States)

Wu, Haoyu; Mendez, Alejandro Rodriguez; Xiong, Shaomin; Bogy, David B.

2015-05-01

In heat assisted magnetic recording (HAMR) technology for hard disk drives, the media will be heated to about 500 °C during the writing process in order to reduce its magnetic coercivity and thus allow data writing with the magnetic head transducers. The traditional lubricants such as Z-dol and Z-tetraol may not be able to perform in such harsh heating conditions due to evaporation, decomposition and thermal depletion. However, some of the lubricant depletion can be recovered due to reflow after a period of time, which can help to reduce the chance of head disk interface failure. In this study, experiments of lubricant thermal depletion and reflow were performed using a HAMR test stage for a Z-tetraol type lubricant. Various lubricant depletion profiles were generated using different laser heating conditions. The lubricant reflow process after thermal depletion was monitored by use of an optical surface analyzer. In addition, a continuum based lubrication model was developed to simulate the lubricant reflow process. Reasonably good agreement between simulations and experiments was achieved.
Traction and lubricant film temperature as related to the glass transition temperature and solidification. [using infrared spectroscopy on EHD contacts

Science.gov (United States)

Lauer, J. L.; Peterkin, M. E.

1978-01-01

Does a traction fluid have to be a glass or solid under operating conditions. Infrared spectra on dynamic EHD contacts of several types of fluid were used to determine the surface and oil-film temperatures. Polarized spectral runs were made to study molecular alignment. Static glass transition pressures at appropriate temperatures were between 0.1 and 2.0 GPa, with the traction fluid showing the highest. In the EHD contact region, the traction fluid showed both the highest film temperatures as well as the greatest degree of molecular alignment. A plot of the difference between the film and surface temperatures vs shear rate resulted in a master plot valid for all the fluids. From this work, the authors propose a model of 'fluid' traction, where friction between parallel rough molecules provides the traction.
Boundary mode lubrication of articular cartilage by recombinant human lubricin.

Science.gov (United States)

Gleghorn, Jason P; Jones, Aled R C; Flannery, Carl R; Bonassar, Lawrence J

2009-06-01

Lubrication of cartilage involves a variety of physical and chemical factors, including lubricin, a synovial glycoprotein that has been shown to be a boundary lubricant. It is unclear how lubricin boundary lubricates a wide range of bearings from tissue to artificial surfaces, and if the mechanism is the same for both soluble and bound lubricin. In the current study, experiments were conducted to investigate the hypothesis that recombinant human lubricin (rh-lubricin) lubricates cartilage in a dose-dependent manner and that soluble and bound fractions of rh-lubricin both contribute to the lubrication process. An rh-lubricin dose response was observed with maximal lubrication achieved at concentrations of rh-lubricin greater than 50 microg/mL. A concentration-response variable-slope model was fit to the data, and indicated that rh-lubricin binding to cartilage was not first order. The pattern of decrease in equilibrium friction coefficient indicated that aggregation of rh-lubricin or steric arrangement may regulate boundary lubrication. rh-lubricin localized at the cartilage surface was found to lubricate a cartilage-glass interface in boundary mode, as did soluble rh-lubricin at high concentrations (150 microg/mL); however, the most effective lubrication occurred when both soluble and bound rh-lubricin were present at the interface. These findings point to two distinct mechanisms by which rh-lubricin lubricates, one mechanism involving lubricin bound to the tissue surface and the other involving lubricin in solution. Copyright 2008 Orthopaedic Research Society
Synthetics, mineral oils, and bio-based lubricants chemistry and technology

CERN Document Server

Rudnick, Leslie R

2005-01-01

As the field of tribology has evolved, the lubrication industry is also progressing at an extraordinary rate. Updating the author's bestselling publication, Synthetic Lubricants and High-Performance Functional Fluids, this book features the contributions of over 60 specialists, ten new chapters, and a new title to reflect the evolving nature of the field: Synthetics, Mineral Oils, and Bio-Based Lubricants: Chemistry and Technology. The book contains chapters on all major lubricant fluids used in a wide range of applications. For each type of lubricant, the authors discuss the historical develo
Excellent lubricating behavior of Brasenia schreberi mucilage.

Science.gov (United States)

Li, Jinjin; Liu, Yuhong; Luo, Jianbin; Liu, Pengxiao; Zhang, Chenhui

2012-05-22

The present work reports an excellent lubrication property of an aquatic plant called Brasenia schreberi (BS). To investigate the lubrication characteristics of the BS mucilage, a novel measuring system is designed, and an ultralow friction coefficient about 0.005 between the mucilage and glass surface has been obtained. It is found that the ultralow friction is closely related to the structure of mucilage and water molecules in the mucilage. The microstructure analysis indicates that the mucilage surrounding BS forms a kind of polysaccharide gel with many nanosheets. A possible lubrication mechanism is proposed that the formation of hydration layers among these polymer nanosheets with plenty of bonded water molecules causes the ultralow friction. The excellent lubrication property has a potential application for reducing the friction between a glossy pill coated with such layer of mucilage and people's throats.
Numerical analysis of capillary compensated micropolar fluid lubricated hole-entry journal bearings

Directory of Open Access Journals (Sweden)

Nathi Ram

2016-06-01

Full Text Available The micropolar lubricated symmetric/asymmetric hole-entry bearings using capillary restrictor have been analyzed in the present work. Reynolds equation for micropolar lubricant has been derived and solved by FEM. The results have been computed using selected parameters of micropolar lubricant for hole-entry hydrostatic/hybrid journal bearings. A significant increase in damping and stiffness coefficients is observed for bearings having micropolar parameter N2=0.9, lm=10 than similar bearings under Newtonian lubricant. The threshold speed gets increased when symmetric bearing lubricated under micropolar fluid than Newtonian lubricant. The threshold speed gets increased when symmetric bearing lubricated under micropolar fluid than Newtonian lubricant.
Lubricity characteristics of marine distillate fuels

Energy Technology Data Exchange (ETDEWEB)

Crutchley, Ian [Innospec Fuel Specialties, Ellesmere Port (United Kingdom); Green, Michael [Intertek Lintec ShipCare Services, Darlington (United Kingdom)

2012-08-15

This article from Innospec Fuel Specialties, Ellesmere Port, UK, and Intertek Lintec ShipCare Services, Darlington, UK, examines the lubricity characteristics of marine distillate fuels available today in relation to the requirements and limits imposed in ISO8217:2010. It will estimate expected failure rates and also asses the perceived relationship between lubricity, sulphur content and viscosity. (orig.)
Advances and patents about grinding equipments with nano-particle jet minimum quantity lubrication.

Science.gov (United States)

Jia, Dongzhou; Li, Changhe; Wang, Sheng; Zhang, Qiang; Hou, Yali

2014-01-01

In recent years, a large number of patents have been devoted to developing minimum quantity lubrication (MQL) grinding techniques that can significantly improve both environmentally conscious and energy saving and costeffective sustainable grinding fluid alternatives. Among them, one patent is about a controllable nano-fluids jet MQL grinding system based on electrostatic atomization. Using the principle of electrostatics, it can achieve the control of droplet transfer by charging the sprayed droplets. This system can improve the uniformity of the droplet spectrum, liquid deposition efficiency and effective utilization of liquid. It can also effectively control the movement patterns of the droplets, thereby reducing the pollution of the environment and providing better health protection for workers. Although researchers accomplished profound and systematic studies on MQL, especially on nano-particles jet MQL. It can solve the shortage of MQL in cooling performance, greatly improve the working environment, save energy and reduce costs to achieve a low-carbon manufacturing. The unique lubricating performance and tribological property of solid nano-particles form nano-particle shearing films at the grinding wheel/workpiece interface, which can enhance the lubricating performance of MQL grinding. Existing studies on MQL grinding equipments, however, cannot meet the needs of the technological development. Therefore, our research provided a general introduction of the latest patients and research progress of nanoparticles jet MQL grinding equipments presented by the research team from Qingdao Technological University.
Method to improve lubricity of low-sulfur diesel and gasoline fuels

Science.gov (United States)

Erdemir, Ali

2004-08-31

A method for providing lubricity in fuels and lubricants includes adding a boron compound to a fuel or lubricant to provide a boron-containing fuel or lubricant. The fuel or lubricant may contain a boron compound at a concentration between about 30 ppm and about 3,000 ppm and a sulfur concentration of less than about 500 ppm. A method of powering an engine to minimize wear, by burning a fuel containing boron compounds. The boron compounds include compound that provide boric acid and/or BO.sub.3 ions or monomers to the fuel or lubricant.
Assessment of lubricating oil degradation in small motorcycle engine fueled with gasohol

Directory of Open Access Journals (Sweden)

Nakorn Tippayawong

2010-05-01

Full Text Available Assessment of the degradation of lubricating oil was performed on the lubricants which had been used in a small motorcycle engine fueled with gasohol in comparison with the lubricants from gasoline-run engine. The lubricant properties examined in the assessment were lubricating capacity, viscosity and stability to oxidation. Lubricating capacity was evaluated by accelerated wear test on the Timken tester. Lubricating oils from gasohol-run engine appeared to produce about 10% greater wear than that made in oils from gasoline-run engine. There was no significant difference between the effect of gasohol and gasoline on the viscosity of the used lubricating oils. Moreover, no oxidation products in any used oil samples could be detected.
Lubrication from mixture of boric acid with oils and greases

Science.gov (United States)

Erdemir, Ali

1995-01-01

Lubricating compositions including crystalline boric acid and a base lubricant selected from oils, greases and the like. The lubricity of conventional oils and greases can also be improved by adding concentrates of boric acid.
Explanation od sudden temperature dependence of muon catalysis in solid deuterium

CERN Document Server

Gershtejn, S S

2001-01-01

It is indicated, that the elastic scattering of the d mu-meson atoms in the solid deuterium at sufficiently low temperatures (as well as of slow neutrons) occurs on the whole crystalline lattice practically without energy loss, and the inelastic collision with the phonon excitation is low.Therefore, the resonance formation of the dd mu-molecules in the solid deuterium takes place before the d mu mesoatoms thermalization and it explains practically observed independence of the dd mu-molecules formation rate and muon catalysis of the temperatures
Finite element modeling for integrated solid-solid PCM-building material with varying phase change temperatures

Energy Technology Data Exchange (ETDEWEB)

Zhang, D.; Fung, A.S.; Siddiqui, O. [Ryerson Polytechnic Univ., Toronto, ON (Canada). Dept. of Mechanical and Industrial Engineering

2008-08-15

Solid-solid phase change materials (SSPCMs) are used to enhance thermal storage performance and reduce indoor temperature fluctuations in buildings. In this study, a finite element model (FEM) was used to investigate the thermal properties of different types of SSPCMs. An effective heat capacity method was used to develop the model. An integrated PCM-building material was analyzed in relation to temperature and heat flux profiles. Governing equations for the heat transfer process were composed of Navier-Stokes momentum equations; a mass conservation equation; and an energy conservation equation. Effective heat capacity was described as a linear function of the latent heat of fusion on both the heating and cooling processes. Data from the simulation were then compared with an experiment suing drywall, concrete and gypcrete samples. Heat flux across the surfaces and temperatures on the surfaces of the materials were measured. Data were used to validate the finite element model (FEM). Results of the study suggested that heat flux profiles are an effective means of understanding phase change processes. It was concluded that PCMs with lower phase change temperatures lengthened energy releases and improved thermal comfort in the building. 12 refs., 2 tabs., 14 figs.
Cooling lubricants; Kuehlschmierstoffe

Energy Technology Data Exchange (ETDEWEB)

Pfeiffer, W. [Berufsgenossenschaftliches Inst. fuer Arbeitssicherheit, St. Augustin (Germany); Breuer, D. [Berufsgenossenschaftliches Inst. fuer Arbeitssicherheit, St. Augustin (Germany); Blome, H. [Berufsgenossenschaftliches Inst. fuer Arbeitssicherheit, St. Augustin (Germany); Deininger, C. [Berufsgenossenschaftliches Inst. fuer Arbeitssicherheit, St. Augustin (Germany); Hahn, J.U. [Berufsgenossenschaftliches Inst. fuer Arbeitssicherheit, St. Augustin (Germany); Kleine, H. [Berufsgenossenschaftliches Inst. fuer Arbeitssicherheit, St. Augustin (Germany); Nies, E. [Berufsgenossenschaftliches Inst. fuer Arbeitssicherheit, St. Augustin (Germany); Pflaumbaum, W. [Berufsgenossenschaftliches Inst. fuer Arbeitssicherheit, St. Augustin (Germany); Stockmann, R. [Berufsgenossenschaftliches Inst. fuer Arbeitssicherheit, St. Augustin (Germany); Willert, G. [Berufsgenossenschaftliches Inst. fuer Arbeitssicherheit, St. Augustin (Germany); Sonnenschein, G. [Maschinenbau- und Metall-Berufsgenossenschaft, Duesseldorf (Germany)

1996-08-01

As a rule, the base substances used are certain liquid hydrocarbons from mineral oils as well as from native and synthetic oils. Through the addition of further substances the cooling lubricant takes on the particular qualities required for the use in question. Employees working with cooling lubricants are exposed to various hazards. The assessment of the concentrations at the work station is carried out on the basis of existing technical rules for contact with hazardous substances. However, the application/implementation of compulsory investigation and supervision in accordance with these rules is made difficult by the fact that cooling lubricants are, as a rule, made up of complicated compound mixtures. In addition to protecting employees from exposure to mists and vapours from the cooling lubricants, protection for the skin is also of particular importance. Cooling lubricants should not, if at all possible, be brought into contact with the skin. Cleansing the skin and skin care is just as important as changing working clothes regularly, and hygiene and cleanliness at the workplace. Unavoidable emissions are to be immediately collected at the point where they arise or are released and safely disposed of. This means taking into account all sources of emissions. The programme presented in this report therefore gives a very detailed account of the individual protective measures and provides recommendations for the design of technical protection facilities. (orig./MG) [Deutsch] Als Basisstoffe dienen in der Regel bestimmte fluessige Kohlenwasserstoffverbindungen aus Mineraloelen sowie aus nativen oder synthetischen Oelen. Durch die Zugabe von weiteren Stoffen erlangt der Kuehlschmierstoff seine fuer den jeweiligen Anwendungsabfall geforderten Eigenschaften. Beschaeftigte, die mit Kuehlschmierstoffen umgehen, sind unterschiedliche Gefahren ausgesetzt. Die Beurteilung der Kuehlschmierstoffkonzentrationen in der Luft am Arbeitsplatz erfolgt auf der Grundlage bestehender
The effect of lubricating oils on bearing fatigue-life using the Evonik RohMax pitting test procedure

Energy Technology Data Exchange (ETDEWEB)

Bartels, Thorsten [Evonik RohMax Additives GmbH, Darmstadt (Germany)

2009-07-01

A major requirement for modern driveline lubricants is the need to reduce churning losses and friction in order to deliver continual improvements in fuel efficiency. In trying to achieve this oil formulators target lower and lower viscosities, testing the limits of what is acceptable Churning loss reductions are being made by reducing the viscosity of the lubricating oil. Reduced oil viscosities can lead to reduced oil film thicknesses, especially at high operating temperatures. Thinner oil films can lead to an increase in friction, and a decrease in the fatigue-life capacity in lubricated contacts of bearings and gears in several driveline applications. Extensive fluid testing is required. Current test procedures are subject to extremely high variability, and large numbers of experiments are required to develop high confidence in the test conclusions. This publication introduces a new fatigue-life test method, which in our hands provides a clear improvement in test time, cost, and reproducibility. The test's results enable an estimation of the effect of lubricating oils on bearing fatigue-life. This is done by comparing the results to those obtained with reference oils which have also been tested in the standardized bearing tests for lubricating oils. The effects of operating parameters on test accuracy and repeatability have been studied. The parameters studied are oil temperature, contact pressure, speed and the test specimen batch. In addition to the measurement of bearing fatigue-life, the new test may also be used to study gear fatigue-life. We have used this test to investigate the lubrication oils' influence on fatigue-life in bearings and in gears. In order to extend the comparisons to gear performance the reference fluids were evaluated in standard industry test procedures used for determining gear performance, in particular the FZG test rig, thus establishing an extra insight in the fluids' performance by comparing gear test performance
Self-lubricating polymer composites : Tribology and interface

NARCIS (Netherlands)

Shen, Jintao

2015-01-01

In cooperation with SKF, this PhD project focus on the improvement of the tribological performance of self-lubricating composites for dry sliding bearings. Several novel self-lubricating composites with very good performance and low production cost is developed in this research, which perform better
A Biomimetic Approach to Lubricate Engineering Materials

DEFF Research Database (Denmark)

Røn, Troels

lubrication characteristic is dominant via ‘selfhealing’ mechanism. The glycosylated FpHYD5 revealed a better lubrication than HFBI. Two type II hydrophobins function more favorably compared to synthetic amphiphilic copolymer, PEO-PPO-PEO, with a similar molecular weight. This is ascribed to higher amount...
NiF2/NaF:CaF2/Ca Solid-State High-Temperature Battery Cells

Science.gov (United States)

West, William; Whitacre, Jay; DelCastillo, Linda

2009-01-01

Experiments and theoretical study have demonstrated the promise of all-solid-state, high-temperature electrochemical battery cells based on NiF2 as the active cathode material, CaF2 doped with NaF as the electrolyte material, and Ca as the active anode material. These and other all-solid-state cells have been investigated in a continuing effort to develop batteries for instruments that must operate in environments much hotter than can be withstood by ordinary commercially available batteries. Batteries of this type are needed for exploration of Venus (where the mean surface temperature is about 450 C), and could be used on Earth for such applications as measuring physical and chemical conditions in geothermal wells and oil wells. All-solid-state high-temperature power cells are sought as alternatives to other high-temperature power cells based, variously, on molten anodes and cathodes or molten eutectic salt electrolytes. Among the all-solid-state predecessors of the present NiF2/NaF:CaF2/Ca cells are those described in "Solid-State High-Temperature Power Cells" (NPO-44396), NASA Tech Briefs, Vol. 32, No. 5 (May 2008), page 40. In those cells, the active cathode material is FeS2, the electrolyte material is a crystalline solid solution of equimolar amounts of Li3PO4 and LiSiO4, and the active anode material is Li contained within an alloy that remains solid in the intended high operational temperature range.

The investigation of contact line effect on nanosized droplet wetting behavior with solid temperature condition

Science.gov (United States)

Haegon, Lee; Joonsang, Lee

2017-11-01

In many multi-phase fluidic systems, there are essentially contact interfaces including liquid-vapor, liquid-solid, and solid-vapor phase. There is also a contact line where these three interfaces meet. The existence of these interfaces and contact lines has a considerable impact on the nanoscale droplet wetting behavior. However, recent studies have shown that Young's equation does not accurately represent this behavior at the nanoscale. It also emphasized the importance of the contact line effect.Therefore, We performed molecular dynamics simulation to imitate the behavior of nanoscale droplets with solid temperature condition. And we find the effect of solid temperature on the contact line motion. Furthermore, We figure out the effect of contact line force on the wetting behavior of droplet according to the different solid temperature condition. With solid temperature condition variation, the magnitude of contact line friction decreases significantly. We also divide contact line force by effect of bulk liquid, interfacial tension, and solid surface. This work was also supported by the National Research Foundation of Korea (NRF) Grant funded by the Korean Government (MSIP) (No. 2015R1A5A1037668) and BrainKorea21plus.
Growth, structure, and tribological behavior of atomic layer-deposited tungsten disulphide solid lubricant coatings with applications to MEMS

International Nuclear Information System (INIS)

Scharf, T.W.; Prasad, S.V.; Dugger, M.T.; Kotula, P.G.; Goeke, R.S.; Grubbs, R.K.

2006-01-01

This paper describes the synthesis, structure, and tribological behavior of nanocomposite tungsten disulphide (WS 2 ) solid lubricant films grown by atomic layer deposition. A new catalytic route, incorporating a diethyl zinc catalyst, was established to promote the adsorption and growth of WS 2 . The films were grown down to 8 nm in thickness by sequential exposures of WF 6 and H 2 S gases in a viscous flow reactor on Si, SiO 2 , stainless steel, and polycrystalline Si and electroplated Ni microelectromechanical systems structures. Films were studied by cross-sectional transmission electron microscopy (XTEM) with Automated eXpert Spectral Image Analysis (AXSIA) software for X-ray spectral images and X-ray diffraction to determine the coating conformality and crystallinity. The coatings exhibited a hexagonal layered structure with predominant preferentially orientated (0 0 2) basal planes. Regardless of orientation to the substrate surface, these basal planes when sheared imparted low friction with a steady-state friction coefficient as low as 0.008 to 50,000 cycles in a dry nitrogen environment. The formation of smooth transfer films during wear provided low interfacial shear stresses during sliding thus achieving low friction and wear. The XTEM combined with AXSIA of the wear tracks identified this mechanism and the effects of vapor phase reaction by-product etching on insulating and native polycrystalline Si and Ni surfaces
Hydrogen production through high-temperature electrolysis in a solid oxide cell

International Nuclear Information System (INIS)

Herring, J.St.; Lessing, P.; O'Brien, J.E.; Stoots, C.; Hartvigsen, J.; Elangovan, S.

2004-01-01

An experimental research programme is being conducted by the INEEL and Ceramatec, Inc., to test the high-temperature, electrolytic production of hydrogen from steam using a solid oxide cell. The research team is designing and testing solid oxide cells for operation in the electrolysis mode, producing hydrogen rising a high-temperature heat and electrical energy. The high-temperature heat and the electrical power would be supplied simultaneously by a high-temperature nuclear reactor. Operation at high temperature reduces the electrical energy requirement for electrolysis and also increases the thermal efficiency of the power-generating cycle. The high-temperature electrolysis process will utilize heat from a specialized secondary loop carrying a steam/hydrogen mixture. It is expected that, through the combination of a high-temperature reactor and high-temperature electrolysis, the process will achieve an overall thermal conversion efficiency of 40 to 50%o while avoiding the challenging chemistry and corrosion issues associated with the thermochemical processes. Planar solid oxide cell technology is being utilised because it has the best potential for high efficiency due to minimized voltage and current losses. These losses also decrease with increasing temperature. Initial testing has determined the performance of single 'button' cells. Subsequent testing will investigate the performance of multiple-cell stacks operating in the electrolysis mode. Testing is being performed both at Ceramatec and at INEEL. The first cells to be tested were single cells based on existing materials and fabrication technology developed at Ceramatec for production of solid oxide fuel cells. These cells use a relatively thick (∼ 175 μm) electrolyte of yttria- or scandia-stabilised zirconia, with nickel-zirconia cermet anodes and strontium-doped lanthanum manganite cathodes. Additional custom cells with lanthanum gallate electrolyte have been developed and tested. Results to date have
Electrode Design for Low Temperature Direct-Hydrocarbon Solid Oxide Fuel Cells

Science.gov (United States)

Chen, Fanglin (Inventor); Zhao, Fei (Inventor); Liu, Qiang (Inventor)

2015-01-01

In certain embodiments of the present disclosure, a solid oxide fuel cell is described. The solid oxide fuel cell includes a hierarchically porous cathode support having an impregnated cobaltite cathode deposited thereon, an electrolyte, and an anode support. The anode support includes hydrocarbon oxidation catalyst deposited thereon, wherein the cathode support, electrolyte, and anode support are joined together and wherein the solid oxide fuel cell operates a temperature of 600.degree. C. or less.
Electrode design for low temperature direct-hydrocarbon solid oxide fuel cells

Science.gov (United States)

Chen, Fanglin; Zhao, Fei; Liu, Qiang

2015-10-06

In certain embodiments of the present disclosure, a solid oxide fuel cell is described. The solid oxide fuel cell includes a hierarchically porous cathode support having an impregnated cobaltite cathode deposited thereon, an electrolyte, and an anode support. The anode support includes hydrocarbon oxidation catalyst deposited thereon, wherein the cathode support, electrolyte, and anode support are joined together and wherein the solid oxide fuel cell operates a temperature of 600.degree. C. or less.
Application of a Biodegradable Lubricant in a Diesel Vehicle

DEFF Research Database (Denmark)

Schramm, Jesper

2003-01-01

The IEA Advanced Motor Fuels Agreement has initiated this project concerning the application of biodegradable lubricants to diesel and gasoline type vehicles. Emission measurements on a chassis dynamometer were carried out. The purpose of these measurements was to compare the emissions of CO, CO2......, NOx, THC, PM, lubricant-SOF and PAH from one diesel and one gasoline type vehicle using biodegradable lubricants and conventional lubricants. This paper describes the results of the experiments with the diesel type vehicle only. Lubricant consumption and fuel consumption are other important parameters...... that have been evaluated during the experiments. Both vehicle types were operated on conventional crude oil based fuels and alternative fuels. The diesel vehicle was operated on conventional diesel fuel from a Danish fuel station, low sulfur diesel from Sweden and biodiesel, which was bought at a fuel...
Investigation of lubricants under boundary friction

Science.gov (United States)

Heidebroek, E; Pietsch, E

1942-01-01

Numerous observations of such lubrication processes within range of boundary friction on journal bearings and gear tooth profiles have strengthened the supposition that it should be possible to study the attendant phenomena with engineering methods and equipment. These considerations formed the basis of the present studies, which have led to the discovery of relations governing the suitability of bearing surfaces and the concept of "lubricating quality."
Simultaneous Effects of Total Solids Content, Milk Base, Heat Treatment Temperature and Sample Temperature on the Rheological Properties of Plain Stirred Yogurt

Directory of Open Access Journals (Sweden)

Attilio Converti

2006-01-01

Full Text Available Response surface methodology was used to establish a relationship between total solids content, milk base, heat treatment temperature, and sample temperature, and consistency index, flow behaviour index, and apparent viscosity of plain stirred yogurts. Statistical treatments resulted in developments of mathematical models. All samples presented shear thinning fluid behaviour. The increase of the content of total solids (9.3–22.7 % and milk base heat treatment temperature (81.6–98.4 °C resulted in a significant increase in consistency index and a decrease in flow behaviour index. Increase in the sample temperature (1.6–18.4 °C caused a decrease in consistency index and increase in flow behaviour index. Apparent viscosity was directly related to the content of total solids. Rheological properties of yogurt were highly dependent on the content of total solids in milk.
Soft lubrication

Science.gov (United States)

Skotheim, Jan; Mahadevan, Laksminarayanan

2004-11-01

We study the lubrication of fluid-immersed soft interfaces and show that elastic deformation couples tangential and normal forces and thus generates lift. We consider materials that deform easily, due to either geometry (e.g a shell) or constitutive properties (e.g. a gel or a rubber), so that the effects of pressure and temperature on the fluid properties may be neglected. Four different system geometries are considered: a rigid cylinder moving tangentially to a soft layer coating a rigid substrate; a soft cylinder moving tangentially to a rigid substrate; a cylindrical shell moving tangentially to a rigid substrate; and finally a journal bearing coated with a thin soft layer, which being a conforming contact allows us to gauge the influence of contact geometry. In addition, for the particular case of a soft layer coating a rigid substrate we consider both elastic and poroelastic material responses. Finally, we consider the role of contact geometry in the context of the journal bearing, a conforming contact. For all these cases we find the same generic behavior: there is an optimal combination of geometric and material parameters that maximizes the dimensionless normal force as a function of the softness.
Micro-Plasto-Hydrodynamic Lubrication a Fundamental Mechanism in Cold Rolling

DEFF Research Database (Denmark)

Laugier, Maxime; Boman, Romain; Legrand, Nicolas

2014-01-01

This paper presents recent investigations in Micro-Plasto-Hydrodynamic (MPH) lubrication. Industrial evidences of the existence of MPH lubrication mechanism for cold rolling processes are presented. A new lubrication model developed for strip drawing processes is then applied to predict the MPH...
The Lubricity of Glycerol and its Solutions

DEFF Research Database (Denmark)

Sivebæk, Ion Marius; Jakobsen, J.

2016-01-01

Glycerol has been recognised as an excellent diesel fuel and lubricant. It is a liquid that can originate from the transesterification of plant oil that also results in plant oil metyl (or ethyl) ester (biodiesel). Machine elements lubricated by glycerol show very low friction, in fact lower than...
Piston ring lubrication and hydrocarbon emissions from internal combustion engines

Energy Technology Data Exchange (ETDEWEB)

Froelund, K.

1997-11-01

Is it the intention with this project to improve the existing hydrocarbon emission model at the Institute by combining it with a model for predicting the piston ring lubrication. The piston ring lubrication model should be experimentally verified to ensure the validity of the model. The following items were the objectives of the current study: Develop a piston ring lubrication model. This implies the development of a ring-pack gas flow model; Examine the response of the piston ring lubrication model to changing engineer conditions. Especially, it would be interesting to look at the engine warm-up phase since this is the phase where the engine-out emissions are highest and where the commonly used three way catalyst is not capable of converting the engine-out emissions, thereby leading the engine-out emissions directly out in to the environment with the exhaust gases; In order to verify the piston ring lubrication model the lubricant distribution on the cylinder liner should be investigated experimentally. Here again it would be of great interesting to look at the engine warm-up phase; The piston ring lubrication model should be adjusted for application together with the new hydrocarbon emission model for SI-engines at the Institute in order to increase the accuracy of the latter; The piston ring lubrication model could be used for describing the transport of PAH`s in diesel engines. (EG)
Graphite and Hybrid Nanomaterials as Lubricant Additives

Directory of Open Access Journals (Sweden)

Zhenyu J. Zhang

2014-04-01

Full Text Available Lubricant additives, based on inorganic nanoparticles coated with organic outer layer, can reduce wear and increase load-carrying capacity of base oil remarkably, indicating the great potential of hybrid nanoparticles as anti-wear and extreme-pressure additives with excellent levels of performance. The organic part in the hybrid materials improves their flexibility and stability, while the inorganic part is responsible for hardness. The relationship between the design parameters of the organic coatings, such as molecular architecture and the lubrication performance, however, remains to be fully elucidated. A survey of current understanding of hybrid nanoparticles as lubricant additives is presented in this review.
A preventive maintenance lubricant

Energy Technology Data Exchange (ETDEWEB)

Chapaykina, S A; Ol' kov, P L; Pertsev, A N; Rodzevillo, I T; Rogacheva, O I; Zinov' yev, A P

1980-02-15

A method is disclosed to lower the adherence of materials by reducing the viscosity of a preventive maintenance lubricant against adhesion of moist, freeflowing materials, containing extract of selective cleaning of oil fractions and asphalt. Gas oil of catalytic cracking is added having a boiling point of 190-300 degrees, with the following ratio of components (%): selective cleaning extract, 43-50; asphalt, 14-16; and gas oil of catalytic cracking, the remainder, Treating a surface with the proposed lubricant lowers the specific resistance to shift of rock compared with the prototype (g/cm/sup 2/): sand (moisture content, 18%) from 3.82 to 1.55; and clay (moisture content 16%), from 5.41 to 3.51.
Solid lubricant behavior of MoS2 and WSe2-based nanocomposite coatings

Science.gov (United States)

Domínguez-Meister, Santiago; Rojas, Teresa Cristina; Brizuela, Marta; Sánchez-López, Juan Carlos

2017-12-01

Tribological coatings made of MoS2 and WSe2 phases and their corresponding combinations with tungsten carbide (WC) were prepared by non-reactive magnetron sputtering of individual targets of similar composition. A comparative tribological analysis of these multiphase coatings was done in both ambient air (30-40% relative humidity, RH) and dry nitrogen (RHgoverns the tribological behavior for each type of environment. This allowed conclusions to be made about the influence of the coating microstructure and composition on the tribological response. The best performance obtained with a WSex film (specific wear rate of 2 × 10-8 mm3 N-1m-1 and a friction coefficient of 0.03-0.05) was compared with that of the well-established MoS2 lubricant material.
Effect of Nitric Acid on the Low Fluorescing Performance of Drilling Fluid Lubricant Based Animal and Vegetable Oils

Directory of Open Access Journals (Sweden)

Feng-shan Zhou

2013-01-01

Full Text Available After synthesis of mixed fatty acid triethanolamine ester surfactant based on animal and vegetable mixed oils, the reaction solution was added into 4% (wt/wt liquid nitric acid or 9% (wt/wt solid nitric acid as eliminating fluorescent agent continuing to react from 1 to 2 hours. The low fluorescence lubricant named E167 for drilling fluid was prepared, in which maximum fluorescence intensity (Fmax was less than 10 in three-dimensional fluorescence spectra of excitation wavelength range. When the E167 was added into fresh water based drilling fluid at the dosage of 0.5% (wt/wt, the sticking coefficient reduced rate (ΔKf is 78% and the extreme pressure (E-P friction coefficient reduced rate (Δf is 79%. In the case of 4% brine mud with 0.5% (wt/wt E167 in it, the ΔKf and Δf are 75% and 62%, respectively. After the hot rolling ageing test 180°C × 16 h with the E167 was added into fresh water based drilling fluid at the dosage of 1% (wt/wt, the ΔKf and Δf are greater than 70%, which shows a much better lubrication properties of strong resistance to high temperature. The fresh water based drilling fluid which contains 1% (wt/wt E167 is almost nonfoaming even after hot rolling ageing 120°C × 16 h.
Diesel fuel lubricity testing revisited : Tests von Dieselkraftstoffschmierfähigkeit erneut betrachtet

NARCIS (Netherlands)

van Leeuwen, H.J.

2017-01-01

Fuel is used as a lubricant in several engine components. Diesel fuel is known for its good lubrication properties, better than gasoline. These properties are examined in standard tests, as prescribed by ASTM. Good lubrication properties are designated as a good lubricity. Most commonly, fuel
Tribology and energy efficiency: from molecules to lubricated contacts to complete machines.

Science.gov (United States)

Taylor, Robert Ian

2012-01-01

The impact of lubricants on energy efficiency is considered. Molecular details of base oils used in lubricants can have a great impact on the lubricant's physical properties which will affect the energy efficiency performance of a lubricant. In addition, molecular details of lubricant additives can result in significant differences in measured friction coefficients for machine elements operating in the mixed/boundary lubrication regime. In single machine elements, these differences will result in lower friction losses, and for complete systems (such as cars, trucks, hydraulic circuits, industrial gearboxes etc.) lower fuel consumption or lower electricity consumption can result.
Tribological properties of amorphous hydrogenated (a-C:H) and hydrogen-free tetrahedral (ta-C) diamond-like carbon coatings under jatropha biodegradable lubricating oil at different temperatures

International Nuclear Information System (INIS)

Mobarak, H.M.; Masjuki, H.H.; Mohamad, E. Niza; Kalam, M.A.; Rashedul, H.K.; Rashed, M.M.; Habibullah, M.

2014-01-01

Highlights: • We tested a-C:H and ta-C DLC coatings as a function of temperature. • Jatropha oil contains large amounts of polar components that enhanced the lubricity of coatings. • CoF decreases with increasing temperature for both contacts. • Wear rate increases with increasing temperature in a-C:H and decreases in ta-C DLC. • At high temperature, ta-C coatings confer more protection than a-C:H coatings. - Abstract: The application of diamond-like carbon (DLC) coatings on automotive components is emerging as a favorable strategy to address the recent challenges in the industry. DLC coatings can effectively lower the coefficient of friction (CoF) and wear rate of engine components, thereby improving their fuel efficiency and durability. The lubrication of ferrous materials can be enhanced by a large amount of unsaturated and polar components of oils. Therefore, the interaction between nonferrous coatings (e.g., DLC) and vegetable oil should be investigated. A ball-on-plate tribotester was used to run the experiments. Stainless steel plates coated with amorphous hydrogenated (a-C:H) DLC and hydrogen-free tetrahedral (ta-C) DLC that slide against 440C stainless steel ball were used to create a ball-on-plate tribotester. The wear track was investigated through scanning electron microscopy. Energy dispersive and X-ray photoelectron spectroscopies were used to analyze the tribofilm inside the wear track. Raman analysis was performed to investigate the structural changes in the coatings. At high temperatures, the CoF in both coatings decreased. The wear rate, however, increased in the a-C:H but decreased in the ta-C DLC-coated plates. The CoF and the wear rate (coated layer and counter surface) were primarily influenced by the graphitization of the coating. Tribochemical films, such as polyphosphate glass, were formed in ta-C and acted as protective layers. Therefore, the wear rate of the ta-C DLC was lower than that of the-C:H DLC
Tribological properties of amorphous hydrogenated (a-C:H) and hydrogen-free tetrahedral (ta-C) diamond-like carbon coatings under jatropha biodegradable lubricating oil at different temperatures

Energy Technology Data Exchange (ETDEWEB)

Mobarak, H.M., E-mail: mobarak.ho31@yahoo.com; Masjuki, H.H.; Mohamad, E. Niza, E-mail: edzrol@um.edu.my; Kalam, M.A.; Rashedul, H.K.; Rashed, M.M.; Habibullah, M.

2014-10-30

Highlights: • We tested a-C:H and ta-C DLC coatings as a function of temperature. • Jatropha oil contains large amounts of polar components that enhanced the lubricity of coatings. • CoF decreases with increasing temperature for both contacts. • Wear rate increases with increasing temperature in a-C:H and decreases in ta-C DLC. • At high temperature, ta-C coatings confer more protection than a-C:H coatings. - Abstract: The application of diamond-like carbon (DLC) coatings on automotive components is emerging as a favorable strategy to address the recent challenges in the industry. DLC coatings can effectively lower the coefficient of friction (CoF) and wear rate of engine components, thereby improving their fuel efficiency and durability. The lubrication of ferrous materials can be enhanced by a large amount of unsaturated and polar components of oils. Therefore, the interaction between nonferrous coatings (e.g., DLC) and vegetable oil should be investigated. A ball-on-plate tribotester was used to run the experiments. Stainless steel plates coated with amorphous hydrogenated (a-C:H) DLC and hydrogen-free tetrahedral (ta-C) DLC that slide against 440C stainless steel ball were used to create a ball-on-plate tribotester. The wear track was investigated through scanning electron microscopy. Energy dispersive and X-ray photoelectron spectroscopies were used to analyze the tribofilm inside the wear track. Raman analysis was performed to investigate the structural changes in the coatings. At high temperatures, the CoF in both coatings decreased. The wear rate, however, increased in the a-C:H but decreased in the ta-C DLC-coated plates. The CoF and the wear rate (coated layer and counter surface) were primarily influenced by the graphitization of the coating. Tribochemical films, such as polyphosphate glass, were formed in ta-C and acted as protective layers. Therefore, the wear rate of the ta-C DLC was lower than that of the-C:H DLC.

Lubrication and thermal characteristics of mechanical seal with porous surface based on cavitation

Science.gov (United States)

Huilong, Chen; Muzi, Zuo; Tong, Liu; Yu, Wang; Cheng, Xu; Qiangbo, Wu

2014-04-01

The theory model of mechanical seals with laser-textured porous surface (LST-MS) was established. The liquid film of LST-MS was simulated by the Fluent software, using full cavitation model and non-cavitation model separately. Dynamic mesh technique and relationship between viscosity and temperature were applied to simulate the internal flow field and heat characteristics of LST-MS, based on the more accurate cavitation model. Influence of porous depth ratio porous diameter ɛ and porous density SP on lubrication performance and the variation of lubrication and thermal properties with shaft speed and sealing pressure were analyzed. The results indicate that the strongest hydrodynamic pressure effect and the biggest thickness of liquid film are obtained when ɛ and SP are respectively about 0.025 and 0.5 which were thought to be the optimum value. The frictional heat leads to the increase of liquid film temperature and the decrease of medium viscosity with the shaft speed increasing. The hydrodynamic pressure effect increases as shaft speed increasing, however it decreases as the impact of frictional heat.
Developments of New Lubricants for Cold Forging of Stainless Steel

DEFF Research Database (Denmark)

Steenberg, Thomas; Christensen, Erik; Olesen, P.

1997-01-01

Two new lubricant systems for cold forging of stainless steel have been developed. The main component of these systems are FeCl3 and ZnCa2(PO4)2, respectively. Both lubricant systems have been tested using a backward extrusion test. The results show excellent lubricating properties with respect...
Numerical methods and computers used in elastohydrodynamic lubrication

Science.gov (United States)

Hamrock, B. J.; Tripp, J. H.

1982-01-01

Some of the methods of obtaining approximate numerical solutions to boundary value problems that arise in elastohydrodynamic lubrication are reviewed. The highlights of four general approaches (direct, inverse, quasi-inverse, and Newton-Raphson) are sketched. Advantages and disadvantages of these approaches are presented along with a flow chart showing some of the details of each. The basic question of numerical stability of the elastohydrodynamic lubrication solutions, especially in the pressure spike region, is considered. Computers used to solve this important class of lubrication problems are briefly described, with emphasis on supercomputers.
Effect of gamma radiation on graphite – PTFE dry lubrication system

International Nuclear Information System (INIS)

Singh, Sachin; Tyagi, Mukti; Seshadri, Geetha; Tyagi, Ajay Kumar; Varshney, Lalit

2017-01-01

An effect of gamma radiation on lubrication behavior of graphite -PTFE dry lubrication system has been studied using (TR-TW-30L) tribometer with thrust washer attachment in plane contact. Different compositions of graphite and PTFE were prepared and irradiated by gamma rays. Gamma radiation exposure significantly improves the tribological properties indicated by decrease in coefficient of friction and wear properties of graphite -PTFE dry lubrication system. SEM and XRD analysis confirm the physico-chemical modification of graphite-PTFE on gamma radiation exposure leading to a novel dry lubrication system with good slip and anti friction properties. - Highlights: • Novel dry lubrication system of graphite -PTFE using gamma radiation. • Gamma radiation processing. • Reduction in coefficient of friction, frictional torque and wear loss of developed dry lubrication system.
Used lubricants and ecological problems

International Nuclear Information System (INIS)

Evdokimov, A.Yu.; Dzhamalov, A.A.; Lashkhi, V.L.

1993-01-01

This planet is undergoing a severe ecological crisis. The consequent problems include not only how to prevent the destruction of contemporary civilization, but also how to preserve mankind as a biological species. In the onset of this crisis, used lubricants (ULs) play a role that is by no means the least important. Every year, the worldwide discharge of petroleum products to the biosphere is approximately 6 million tonnes, of which more than 50% consists of ULs. The ecologically dangerous components of both commercial lubricants and used lubricants are the polycyclic aromatic hydrocarbons (PAHs) that are originally present in crude oil; polyhalobiphenyls, mainly polychlorobiphenyls (PCBs) of anthropogenic origin; sulfur- and chlorine-containing additives; a number of biocides; organic compounds of metals (lead, barium, antimony, zinc); and nitrites. These substances are distributed in the atmosphere, water, and soil, entering the food chain and appearing in foodstuffs. Moreover, hydrocarbons of petroleum and synthetic oils with a low degree of biodegradability (10-30%) accumulate in the environment and may shift the ecological equilibrium (accelerated multiplication and mutation of microorganisms that assimilate petroleum products). 32 refs., 1 fig
Compatibility of refrigerants and lubricants with elastomers

Energy Technology Data Exchange (ETDEWEB)

Hamed, G.R.; Seiple, R.H.

1993-01-01

The information contained in this report is designed to assist the air-conditioning and refrigeration industry in the selection of suitable elastomeric gasket and seal materials that will prove useful in various refrigerant and refrigeration lubricant environments. 97% of the swell measurements have been made to date. The other 3% of the measurements are contingent on availability of additional R-32. Swell behavior in the fluids have been determined using weight and in situ diameter measurements for the refrigerants and weight, diameter and thickness measurements for the lubricants. Weight and diameter measurements are repeated after 2 and 24 hours for samples removed from the refrigerant test fluids and 24 hours after removal from the lubricants.
Fuels and Lubricants Facility

Data.gov (United States)

Federal Laboratory Consortium — Modern naval aircraft and turbine-powered craft require reliable and high-quality fuels and lubricants to satisfy the demands imposed upon them for top performance...
Complex hydrides as room-temperature solid electrolytes for rechargeable batteries

DEFF Research Database (Denmark)

Jongh, P. E. de; Blanchard, D.; Matsuo, M.

2016-01-01

A central goal in current battery research is to increase the safety and energy density of Li-ion batteries. Electrolytes nowadays typically consist of lithium salts dissolved in organic solvents. Solid electrolytes could facilitate safer batteries with higher capacities, as they are compatible...... electrolytes, discussing in detail LiBH4, strategies towards for fast room-temperature ionic conductors, alternative compounds, and first explorations of implementation of these electrolytes in all-solid-state batteries....
Functional regulation of Pb-Ti/MoS{sub 2} composite coatings for environmentally adaptive solid lubrication

Energy Technology Data Exchange (ETDEWEB)

Ren, Siming [Key Laboratory of Marine Materials and Related Technologies, Key Laboratory of Marine Materials and Protective Technologies of Zhejiang Province, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); University of Chinese Academy of Sciences, Beijing 100039 (China); Li, Hao [Key Laboratory of Advanced Technologies of Materials (Ministry of Education), School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031 (China); Cui, Mingjun [Key Laboratory of Marine Materials and Related Technologies, Key Laboratory of Marine Materials and Protective Technologies of Zhejiang Province, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); University of Chinese Academy of Sciences, Beijing 100039 (China); Wang, Liping, E-mail: wangliping@nimte.ac.cn [Key Laboratory of Marine Materials and Related Technologies, Key Laboratory of Marine Materials and Protective Technologies of Zhejiang Province, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Pu, Jibin, E-mail: pujibin@nimte.ac.cn [Key Laboratory of Marine Materials and Related Technologies, Key Laboratory of Marine Materials and Protective Technologies of Zhejiang Province, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China)

2017-04-15

Highlights: • Co-doped Pb-Ti/MoS{sub 2} composite coatings were successfully fabricated by unbalanced magnetron sputtering system. • Co-doped Pb-Ti/MoS{sub 2} composite coatings showed lower friction coefficient and longer wear life in both humid and vacuum environments than that of single-doped ones. • The wear behaviours of Pb-Ti/MoS{sub 2} composite coatings with the increase of Pb content is in accordance with the variation in H/E ratio that higher H/E is corresponding to the lower wear rate of coating. - Abstract: The lubrication of molybdenum disulfide coatings has commonly been limited by the application environments, for instance, the crystal MoS{sub 2} are easily affected by water to form MoO{sub 3} that causes a higher friction coefficient and short lifetime. Therefore, to improve the tribolgical performance of MoS{sub 2} in high humidity condition, the co-doped Pb-Ti/MoS{sub 2} composite coatings are deposited by unbalanced magnetron sputtering system. The design of the co-doping elements in MoS{sub 2}-based coatings can not only maintain the characteristic of low humidity-sensitivity as the Ti/MoS{sub 2} coating but also improve the mechanical properties and tribological performance of coatings as a comparison with single-doped ones. Moreover, the ultra-low friction coefficient with a minimum value of 0.006 under the vacuum condition is achieved for Pb-Ti/MoS{sub 2} composite coating containing about 4.6 at.% Pb, depending on the densification structure of coating. Intriguingly, the wear behaviours of Pb-Ti/MoS{sub 2} composite coatings are in accordance with the variation in H/E (hardness to the elastic modulus) ratio that the coating with higher H/E exhibits lower wear rate. These results demonstrate that the lubricating properties of MoS{sub 2} coatings in both humid environment and vacuum condition can be achieved through the Pb and Ti co-doped, which is of great significant for developing MoS{sub 2} coatings as the environmentally adaptive
Lubricant coating of dowel for the ITER vacuum vessel gravity support

Energy Technology Data Exchange (ETDEWEB)

Kim, B.Y. [ITER Korea, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of); Ahn, H.J., E-mail: hjahn@nfri.re.kr [ITER Korea, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of); Bak, J.S. [ITER Korea, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of); Choi, C.H.; Ioki, K. [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance (France); Zauner, C. [KRP-Mechatec Engineering GbR, 85748 Garching b, Muenchen (Germany)

2012-08-15

The ITER vacuum vessel gravity supports located in the lower level shall sustain loads in radial, toroidal and vertical directions. The hinge type VVGS consists of two hinges, upper and lower blocks and dowels. In order to develop the design concept and verify the structural integrity of the hinge system, the design analysis has been performed in detail. Inclination of 15 Degree-Sign for the hinge based supporting system was introduced to provide centering force to make stable equilibrium state of the vacuum vessel. Due to this inclination the hinges are rotated by the radial expansion of the VV during operation and baking, respectively. If a dowel is seized in the hinge, the supporting system can be highly stressed due to the restrained displacement in the seized dowel. Therefore, solid lubricant coatings were suggested on dowels in order to avoid seizing in the sliding area. In this work, several sets of coupons were made with different coating materials to investigate the effect according to the selection of coating material. Also, a test facility was designed to cover the ITER relevant loading and boundary conditions, e.g. vacuum condition, temperature, contact pressure, cycles, etc. From those test results, the optimized coating method was found to avoid seizure of dowel in the ITER VVGS.
Development and efficiency assessment of process lubrication for hot forging

Science.gov (United States)

Kargin, S.; Artyukh, Viktor; Ignatovich, I.; Dikareva, Varvara

2017-10-01

The article considers innovative technologies in testing and production of process lubricants for hot bulk forging. There were developed new compositions of eco-friendly water-graphite process lubricants for hot extrusion and forging. New approaches to efficiency assessment of process lubricants are developed and described in the following article. Laboratory and field results are presented.
Effect of an isotonic lubricant on sperm collection and sperm quality.

Science.gov (United States)

Agarwal, Ashok; Malvezzi, Helena; Sharma, Rakesh

2013-05-01

To assess the influence of an isotonic lubricant used during sperm sample collection on [1] ease of collection and [2] resultant sperm quality. Paired randomized cross-over design. Tertiary hospital. Healthy men over 18 years old with normal semen analysis as per World Health Organization 2010 guidelines. Collection of semen sample from 22 subjects by masturbation with or without the use of Pre-Seed personal lubricant. Qualitative survey results and quantitative sperm function outcomes were measured to determine resultant sperm quality and collection experience with and without Pre-Seed lubricant. The qualitative questionnaire results showed that 73% of donors prefer the semen collection process with the isotonic lubricant and 55% recommended the use of lubricant in their everyday collection. The motility, viability, membrane integrity, levels of reactive oxygen species, total antioxidant capacity, and percentage of DNA damage in collected semen samples were not affected by the use of the lubricant. More donors prefer, and find it easier, to collect semen samples with the use of the lubricant. The isotonic lubricant Pre-Seed did not compromise sperm quality as evaluated in an array of sperm assays, suggesting its safe use in fertility patients as required during sperm collection. Copyright © 2013 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.
High-temperature solid electrolyte interphases (SEI) in graphite electrodes

Science.gov (United States)

Rodrigues, Marco-Tulio F.; Sayed, Farheen N.; Gullapalli, Hemtej; Ajayan, Pulickel M.

2018-03-01

Thermal fragility of the solid electrolyte interphase (SEI) is a major source of performance decay in graphite anodes, and efforts to overcome the issues offered by extreme environments to Li-ion batteries have had limited success. Here, we demonstrate that the SEI can be extensively reinforced by carrying the formation cycles at elevated temperatures. Under these conditions, decomposition of the ionic liquid present in the electrolyte favored the formation of a thicker and more protective layer. Cells in which the solid electrolyte interphase was cast at 90 °C were significantly less prone to self-discharge when exposed to high temperature, with no obvious damages to the formed SEI. This additional resilience was accomplished at the expense of rate capability, as charge transfer became growingly inefficient in these systems. At slower rates, however, cells that underwent SEI formation at 90 °C presented superior performances, as a result of improved Li+ transport through the SEI, and optimal wetting of graphite by the electrolyte. This work analyzes different graphite hosts and ionic liquids, showing that this effect is more pervasive than anticipated, and offering the unique perspective that, for certain systems, temperature can actually be an asset for passivation.
High temperature tribological behaviors of (WAl)C–Co ceramic composites with the additions of fluoride solid lubricants

International Nuclear Information System (INIS)

Cheng, Jun; Qiao, Zhuhui; Yin, Bing; Hao, Junying; Yang, Jun; Liu, Weimin

2015-01-01

The tribological behaviors of the (W 0.67 Al 0.33 )C 0.67 –Co/fluoride (CaF 2 , BaF 2 , CaF 2 /BaF 2 ) composites against SiC ball from room temperature to 600 °C were investigated. A marked increase in the friction coefficient resulting from fluoride oxidation was observed as the temperature increased. The composites containing BaF 2 or (Ca, Ba)F 2 displayed better integrated wear resistance over a wide temperature range compared with (W 0.67 Al 0.33 )C 0.67 –Co/CaF 2 . The high temperature tribological characteristics of the three composites were distinct, which originated from the composition difference on the worn surfaces. First, the SiO 2 /SiC film formed on the worn surfaces of the composites with BaF 2 or (Ca, Ba)F 2 was favorable for their wear resistance. Second, the oxidation of WC matrix was an important factor influencing the wear resistance of the composites. When mixture oxides of WO 2 and WO 3 appeared on the surface, wear is severe. In addition, single WO 3 formed on the worn surfaces, appeared more adhesive to the underlying substrate and decreased the wear rate. - Highlights: • The composites containing BaF 2 or (Ca, Ba)F 2 exhibit better wear resistance. • The tribological behaviors are strongly correlated to surface composition. • The stoichiometry difference in the tungsten oxides leads to distinct wear rate. • The friction coefficient of the composites increases with the testing temperature
Mild wear modeling in the boundary lubrication regime

NARCIS (Netherlands)

Bosman, Rob

2011-01-01

Currently, the increasing demand for smaller and more efficient systems is increasing the stress put on interacting components. This forces components to operate in the boundary lubrication regime. In this lubrication regime, the normal load put on the components is no longer carried by the
Effect of gamma radiation on graphite - PTFE dry lubrication system

Science.gov (United States)

Singh, Sachin; Tyagi, Mukti; Seshadri, Geetha; Tyagi, Ajay Kumar; Varshney, Lalit

2017-12-01

An effect of gamma radiation on lubrication behavior of graphite -PTFE dry lubrication system has been studied using (TR-TW-30L) tribometer with thrust washer attachment in plane contact. Different compositions of graphite and PTFE were prepared and irradiated by gamma rays. Gamma radiation exposure significantly improves the tribological properties indicated by decrease in coefficient of friction and wear properties of graphite -PTFE dry lubrication system. SEM and XRD analysis confirm the physico-chemical modification of graphite-PTFE on gamma radiation exposure leading to a novel dry lubrication system with good slip and anti friction properties.
Biodiesel as a lubricity additive for ultra low sulfur diesel

Directory of Open Access Journals (Sweden)

Subongkoj Topaiboul1 and 2,*

2010-05-01

Full Text Available With the worldwide trend to reduce emission from diesel engines, ultra low sulfur diesel has been introduced with thesulfur concentration of less than 10 ppm. Unfortunately, the desulfurization process inevitably reduces the lubricity of dieselfuel significantly. Alternatively, biodiesel, with almost zero sulfur content, has been added to enhance lubricity in an ultralow sulfur diesel. This work has evaluated the effectiveness of the biodiesel amount, sourced from palm and jatropha oil,and origin in ultra low sulfur diesel locally available in the market. Wear scar from a high-frequency reciprocating rig isbenchmarked to the standard value (460 m of diesel fuel lubricity. It was found that very small amount (less than 1% ofbiodiesel from either source significantly improves the lubricity in ultra low sulfur diesel, and the biodiesel from jatropha oilis a superior lubricity enhancer.
Lubrication analysis of the thrust bearing in the main coolant pump of SMART

International Nuclear Information System (INIS)

Lee, J. S.; Park, J. S.; Kim, J. H.; Hur, H.; Kim, J. I.

2001-01-01

Thrust bearing and journal bearings are installed in the main coolant pump for SMART to support the rotating shaft with proper lubrication. The canned motor type main coolant pumps are arranged vertically on the reactor vessel and especially the MCP bearings are lubricated with water without external lubricating oil supply. Because axial load capacity of the thrust bearing can hardly meet requirement to acquire hydrodynamic or fluid film lubrication state, self-lubrication characteristics of silicon graphite meterials would be needed. Lubricational analysis method for thrust bearing for the main coolant pump of SMART is proposed, and lubricational characteristics of the bearing generated by solving the Reynolds equation are examined in this paper
High temperature tribological behaviors of (WAl)C–Co ceramic composites with the additions of fluoride solid lubricants

Energy Technology Data Exchange (ETDEWEB)

Cheng, Jun; Qiao, Zhuhui, E-mail: zhqiao@licp.cas.cn; Yin, Bing; Hao, Junying, E-mail: jyhao@licp.cas.cn; Yang, Jun; Liu, Weimin

2015-08-01

The tribological behaviors of the (W{sub 0.67}Al{sub 0.33})C{sub 0.67}–Co/fluoride (CaF{sub 2}, BaF{sub 2}, CaF{sub 2}/BaF{sub 2}) composites against SiC ball from room temperature to 600 °C were investigated. A marked increase in the friction coefficient resulting from fluoride oxidation was observed as the temperature increased. The composites containing BaF{sub 2} or (Ca, Ba)F{sub 2} displayed better integrated wear resistance over a wide temperature range compared with (W{sub 0.67}Al{sub 0.33})C{sub 0.67}–Co/CaF{sub 2}. The high temperature tribological characteristics of the three composites were distinct, which originated from the composition difference on the worn surfaces. First, the SiO{sub 2}/SiC film formed on the worn surfaces of the composites with BaF{sub 2} or (Ca, Ba)F{sub 2} was favorable for their wear resistance. Second, the oxidation of WC matrix was an important factor influencing the wear resistance of the composites. When mixture oxides of WO{sub 2} and WO{sub 3} appeared on the surface, wear is severe. In addition, single WO{sub 3} formed on the worn surfaces, appeared more adhesive to the underlying substrate and decreased the wear rate. - Highlights: • The composites containing BaF{sub 2} or (Ca, Ba)F{sub 2} exhibit better wear resistance. • The tribological behaviors are strongly correlated to surface composition. • The stoichiometry difference in the tungsten oxides leads to distinct wear rate. • The friction coefficient of the composites increases with the testing temperature.
Systematic evaluation of common lubricants for optimal use in tablet formulation.

Science.gov (United States)

Paul, Shubhajit; Sun, Changquan Calvin

2018-05-30

As an essential formulation component for large-scale tablet manufacturing, the lubricant preserves tooling by reducing die-wall friction. Unfortunately, lubrication also often results in adverse effects on tablet characteristics, such as prolonged disintegration, slowed dissolution, and reduced mechanical strength. Therefore, the choice of lubricant and its optimal concentration in a tablet formulation is a critical decision in tablet formulation development to attain low die-wall friction while minimizing negative impact on other tablet properties. Three commercially available tablet lubricants, i.e., magnesium stearate, sodium stearyl fumerate, and stearic acid, were systematically investigated in both plastic and brittle matrices to elucidate their effects on reducing die-wall friction, tablet strength, tablet hardness, tablet friability, and tablet disintegration kinetics. Clear understanding of the lubrication efficiency of commonly used lubricants as well as their impact on tablet characteristics would help future tablet formulation efforts. Copyright © 2018 Elsevier B.V. All rights reserved.

Deposited Micro Porous Layer as Lubricant Carrier in Metal Forming

DEFF Research Database (Denmark)

Arentoft, Mogens; Bay, Niels; Tang, Peter Torben

2008-01-01

as lubricant reservoirs. Conventional friction tests for cold forming; ring compression and double cup extrusion tests are carried out with Molykote DX paste and mineral oil as lubricant. Both lubricants act as intended for the ring compressions test whereas only the low viscosity oil perform successfully...... in the cup extrusion test. For all specimens without the porous coating, high friction conditions are identified....
Anomalous low-temperature desorption from preirradiated rare gas solids

International Nuclear Information System (INIS)

Savchenko, E.V.; Gumenchuk, G.B.; Yurtaeva, E.M.; Belov, A.G.; Khyzhniy, I.V.; Frankowski, M.; Beyer, M.K.; Smith-Gicklhorn, A.M.; Ponomaryov, A.N.; Bondybey, V.E.

2005-01-01

The role for the exciton-induced defects in the stimulation of anomalous low-temperature desorption of the own lattice atoms from solid Ar and Ne preirradiated by an electron beam is studied. The free electrons from shallow traps-structural defects-was monitored by the measurements of a yield of the thermally induced exoelectron emission (TSEE). The reaction of recombination of self-trapped holes with electrons is considered as a source of energy needed for the desorption of atoms from the surface of preirradiated solids. A key part of the exciton-induced defects in the phenomenon observed is demonstrated
CHALLENGES IN GENERATING HYDROGEN BY HIGH TEMPERATURE ELECTROLYSIS USING SOLID OXIDE CELLS

Energy Technology Data Exchange (ETDEWEB)

M. S. Sohal; J. E. O' Brien; C. M. Stoots; M. G. McKellar; J. S. Herring; E. A. Harvego

2008-03-01

Idaho National Laboratory’s (INL) high temperature electrolysis research to generate hydrogen using solid oxide electrolysis cells is presented in this paper. The research results reported here have been obtained in a laboratory-scale apparatus. These results and common scale-up issues also indicate that for the technology to be successful in a large industrial setting, several technical, economical, and manufacturing issues have to be resolved. Some of the issues related to solid oxide cells are stack design and performance optimization, identification and evaluation of cell performance degradation parameters and processes, integrity and reliability of the solid oxide electrolysis (SOEC) stacks, life-time prediction and extension of the SOEC stack, and cost reduction and economic manufacturing of the SOEC stacks. Besides the solid oxide cells, balance of the hydrogen generating plant also needs significant development. These issues are process and ohmic heat source needed for maintaining the reaction temperature (~830°C), high temperature heat exchangers and recuperators, equal distribution of the reactants into each cell, system analysis of hydrogen and associated energy generating plant, and cost optimization. An economic analysis of this plant was performed using the standardized H2A Analysis Methodology developed by the Department of Energy (DOE) Hydrogen Program, and using realistic financial and cost estimating assumptions. The results of the economic analysis demonstrated that the HTE hydrogen production plant driven by a high-temperature helium-cooled nuclear power plant can deliver hydrogen at a cost of $3.23/kg of hydrogen assuming an internal rate of return of 10%. These issues need interdisciplinary research effort of federal laboratories, solid oxide cell manufacturers, hydrogen consumers, and other such stakeholders. This paper discusses research and development accomplished by INL on such issues and highlights associated challenges that need to
Evaporation rate and vapor pressure of selected polymeric lubricating oils.

Science.gov (United States)

Gardos, M. N.

1973-01-01

A recently developed ultrahigh-vacuum quartz spring mass sorption microbalance has been utilized to measure the evaporation rates of several low-volatility polymeric lubricating oils at various temperatures. The evaporation rates are used to calculate the vapor pressures by the Langmuir equation. A method is presented to accurately estimate extended temperature range evaporation rate and vapor pressure data for polymeric oils, incorporating appropriate corrections for the increases in molecular weight and the change in volatility of the progressively evaporating polymer fractions. The logarithms of the calculated data appear to follow linear relationships within the test temperature ranges, when plotted versus 1000/T. These functions and the observed effusion characteristics of the fluids on progressive volatilization are useful in estimating evaporation rate and vapor pressure changes on evaporative depletion.
On the Frictional Heating in Single Summit Contacts: Towards Failure at Asperity Level in Lubricated Systems

NARCIS (Netherlands)

van der Heide, Emile; Schipper, Dirk J.

2004-01-01

The influence of surface roughness and thermal conductivity on seizure in lubricated contacts is described in this work by quantifying the action of individual asperities in relation to local surface temperature rise. Application of the model to a contact situation in metal forming of stainless
Design considerations in mechanical face seals for improved performance. 2: Lubrication

Science.gov (United States)

Ludwig, L. P.; Greiner, H. F.

1977-01-01

The importance of sealing technology in our industrial, chemical-oriented society in regard to maintenance and environmental contamination is pointed out. It is stated that seal performance (leakage, life) is directly related to seal lubrication. Current thinking in regard to seal lubrication is reviewed; the effect of energy dissipation in the thin lubricating film separating the sealing faces is pointed out, and the results of vaporization due to heating are illustrated. Also, hydrodynamic lubrication is reviewed, and an inherent tendency for the seal to operate with angular misalignment is shown. Recent work on hydrostatic effects is summarized and the conditions for seal instability are discussed. Four different modes of seal lubrication are postulated with the mode type being a strong function of speed and pressure.
Nanomaterials in Lubricants: An Industrial Perspective on Current Research

Directory of Open Access Journals (Sweden)

Boris Zhmud

2013-11-01

Full Text Available This paper presents an overview on the use of various classes of nanomaterials in lubricant formulations. The following classes of nanomaterials are considered: fullerenes, nanodiamonds, ultradispersed boric acid and polytetrafluoroethylene (PTFE. Current advances in using nanomaterials in engine oils, industrial lubricants and greases are discussed. Results of numerous studies combined with formulation experience of the authors strongly suggest that nanomaterials do indeed have potential for enhancing certain lubricant properties, yet there is a long way to go before balanced formulations are developed.
Lubrication of Space Shuttle Main Engine Turbopump Bearings

Science.gov (United States)

Gibson, Howard; Munafo, Paul (Technical Monitor)

2001-01-01

The Space Shuttle has three main engines that are used for propulsion into orbit. These engines are fed propellants by four turbopumps on each engine. A main element in the turbopump is the bearings supporting the rotor that spins the turbine blades and the pump impeller. These bearings are required to spin at very high speeds, support radial and thrust loads, and have high wear resistance without the benefit of lubrication. The liquid hydrogen and oxygen propellants flow through the bearings to cool the surfaces. The volatile nature of the propellants excludes any conventional means of lubrication. Lubrication for these bearings is provided by the ball separator inside the bearing. The separator is a composite material that supplies a transfer film of lubrication to the rings and balls. New separator materials and lubrication schemes have been investigated at Marshall Space Flight Center in a bearing test rig with promising results. Hybrid bearings with silicon nitride balls have also been evaluated. The use of hybrid, silicon nitride ball bearings in conjunction -with better separator materials has shown excellent results. The work that Marshall has done is being utilized in turbopumps flying on the space shuttle fleet and will be utilized in future space travel. This result of this work is valuable for all aerospace and commercial applications where high-speed bearings are used.
About the influence of lubricating-cooling agents on the cutting process

Directory of Open Access Journals (Sweden)

O.I. Sochko

2017-12-01

Full Text Available Set forth problem of necessity of increase of workability of metal. On the basis of generalization of researches at the area of physics – chemical mechanics of materials the offered hypothesis on the permanent activating of lubricating cooling technological facilities in the zone of cutting to hydrogen plasma, mechanism of her influence on the processes of deformation and destruction, and also reasonable new ways of formation of form of wares. It is in-process shown that lubricating – cooling technological facilities in it in the zone of destruction to the new phase state – hydrogen plasma. It is therefore consisted majority mainly of two elements – hydrogen and carbon, the basic changes of mechanical properties of solid are activated in the conditions of co-operating of body with an environment, it follows to link, with influence of nascent radically-active environment, but not from initial superficially – active. An ambiguousness in the estimation of reasons, at that arises up facilitation of processes of deformation and destructions of solids, that become deformed in different environments caused raising of system researches that is sanctified to this problem. As a result of chemical transformations of initial environment to the level of origin electric of active parts of hydrogen, possibility of their co-operating appears with ions and lone electrons of metal, that increases the electric field, to existing in the system «machine-tool – instrument – purveyance». Exactly co-operation electric of active structure of metal that arises up as a result of mechanical action, with the electric charged mixture of parts of hydrogen, id est an electron-electron, electron-ion and ion-ion, is able co-operation radically to change physical and mechanical properties of metal.
Empirical Investigation of Electricity Self-Generation in a Lubricated Sliding–Rolling Contact

Energy Technology Data Exchange (ETDEWEB)

Ščepanskis, Mihails; Gould, Benjamin; Greco, Aaron

2017-07-20

The paper reports the empirical observations of voltage generation in a lubricated tribocontact with different oils altering load, sliding and temperature. The investigation is done in the context of research of the root cause of white etching cracks (WEC) failure in bearings. Tested oils of different additive packages found completely different electrical behavior. The oil, which is known to produce WECs in laboratory tests, demonstrated non-zero voltage generation
Growth and opportunities in the lubricants business in Asia

International Nuclear Information System (INIS)

Burke, B.F.

1995-01-01

The demand for lubricants is increasing faster in Asia than any other part of the world. This development is being propelled largely by the expansion of the transportation and manufacturing sectors. By the year 2000, lubricant consumption in Asia will exceed that of Western Europe, Africa and the Middle East combined. Aside from this growth, most of the region is shifting from very low quality to higher quality value-added products. In view of these factors, there has been an explosion of activity over the past few years as lubricant blenders and additive suppliers attempt to position themselves within the market. Over the past year, Chem Systems has undertaken an extensive study of the lubricants business in East Asia, focusing on the evolution of this complex market structure and the identification of attractive opportunities. The overview presented in this paper is a product of these efforts. Whether you are a multinational oil company, independent blender, national oil company or multinational additive suppler, the questions are the same when developing a strategy for the region: regional overview of lubricant business structure; outlook for Asian demand; profile of lube/additives businesses; and successful competition--what is required?
Experimental studies in solid state and low temperature physics. Progress report, 1975

International Nuclear Information System (INIS)

Goldman, A.M.; Weyhmann, W.V.; Zimmermann, W. Jr.

1975-09-01

Experimental investigations are being carried out in a broad area of low-temperature and solid-state physics which includes superconductivity, magnetism in metals and liquid and solid helium. The pair-field susceptibility of superconductors is being studied. A propagating mode in the phase of the superconducting order parameter has been found. Heat capacities of superconducting films in the vicinity of T/sub c/ are also being investigated. An investigation in the time-dependent high conductivity of dilute solid solutions of sodium in ammonia has been initiated. Nuclear orientation studies of the dilute magnetic impurity problem in metals in the 1 mK temperature region are being carried out. Refrigeration requirements for this work are being met using enhanced hyperfine nuclear cooling. Measurements of the differential osmotic pressure of 3 He/ 4 He liquid mixtures near the tricritical point have shown a peak in the ''concentration susceptibility'' at the lambda line. Data obey a simple tricritical scaling relation. The dynamics of superfluid flow through submicron pores are being studied in both pure 4 He and in 3 He/ 4 He mixtures in an apparatus provided with a 3 He refrigerator. The quantization of circulation in superfluid liquid 4 He is being investigated using the Vinen method. The low temperature heat capacity of bcc solid 3 He is being studied
Tribology of thin wetting films between bubble and moving solid surface.

Science.gov (United States)

Karakashev, Stoyan I; Stöckelhuber, Klaus W; Tsekov, Roumen; Phan, Chi M; Heinrich, Gert

2014-08-01

This work shows a successful example of coupling of theory and experiment to study the tribology of bubble rubbing on solid surface. Such kind of investigation is reported for the first time in the literature. A theory about wetting film intercalated between bubble and moving solid surface was developed, thus deriving the non-linear evolution differential equation which accounted for the friction slip coefficient at the solid surface. The stationary 3D film thickness profile, which appears to be a solution of the differential equation, for each particular speed of motion of the solid surface was derived by means of special procedure and unique interferometric experimental setup. This allowed us to determine the 3D map of the lift pressure within the wetting film, the friction force per unit area and the friction coefficient of rubbing at different speeds of motion of the solid surface. Thus, we observed interesting tribological details about the rubbing of the bubble on the solid surface like for example: 1. A regime of mixed friction between dry and lubricated friction exists in the range of 6-170 μm/s, beyond which the rubbing between the bubble and solid becomes completely lubricated and passes through the maximum; 2. The friction coefficient of rubbing has high values at very small speeds of solid's motion and reduces substantially with the increase of the speed of the solid motion until reaching small values, which change insignificantly with the further increase of the speed of the solid. Despite the numerous studies on the motion of bubble/droplet in close proximity to solid wall in the literature, the present investigation appears to be a step ahead in this area as far as we were able to derive 3D maps of the bubble close to the solid surface, which makes the investigation more profound. © 2013.
Friction-induced nano-structural evolution of graphene as a lubrication additive

Science.gov (United States)

Zhao, Jun; Mao, Junyuan; Li, Yingru; He, Yongyong; Luo, Jianbin

2018-03-01

Graphene has attracted enormous attention in the field of lubrication based on its excellent physical and chemical properties. Although many studies have obtained thermally or chemically- exfoliated graphene and investigated their wide and important application, few studies have reported their physical nano-structural evolution under friction. In this study, we investigated the lubrication properties of graphene additives with different layer numbers and interlayer spacing by exfoliating. The additives with a higher degrees of exfoliation changed to ordering under friction, and had better lubrication properties, while that with a lower degrees exhibited obvious structural defects and high friction. Therefore, the original degrees of exfoliation plays a key role in the structural evolution of graphene and superior lubrication can be achieved through the physical nano-structure changing to ordering, even graphitization. Furthermore, the ordered tribofilm on the frictional interfaces was parallel to the sliding direction, meaning the highly exfoliated graphene indeed reaching slippage between its layers, which wasn't experimentally discovered in previous studies. This work provides a new understanding of the relationship between friction-induced nano-structural evolution and lubrication properties of graphene as a lubrication additive, and has great potential for the structural design of graphene as a lubrication additive.
Asymptotic approximation of laminar lubrication thermal field at low reduced peclet and Brinkman number

DEFF Research Database (Denmark)

Johansen, Per; Roemer, Daniel Beck; Andersen, Torben Ole

2014-01-01

A conventional simplification of the thermal problem in fluid film lubrication analysis is performed by assuming that the main direction of heat flow is conduction through the film thickness, and thereby neglecting convection. However, in a significant amount of applications, convection is not ne......A conventional simplification of the thermal problem in fluid film lubrication analysis is performed by assuming that the main direction of heat flow is conduction through the film thickness, and thereby neglecting convection. However, in a significant amount of applications, convection...... is not negligible, whereby the majority of design engineers exclusively use numerical solvers. This paper presents a perturbation series expansion of the temperature field for small values of the Brinkman number. The derived perturbation solution and the more conventional analytical solution, where convection...
Determination of Lubricants on Ball Bearings by FT-IR using an Integrating Sphere

Science.gov (United States)

Street, K. W.; Pepper, S. V.; Wright, A.

2003-01-01

The lifetime determination of space lubricants is done at our facility by accelerated testing. Several micrograms of lubricant are deposited on the surface of a ball by syringing tens of micro liters of dilute lubricant solution. The solvent evaporates and the mass of lubricant is determined by twenty weighings near the balance reliability limit. This process is timely but does not produce a good correlation between the mass of lubricant and the volume of solution applied, as would be expected. The amount of lubricant deposited on a ball can be determined directly by Fourier Transform - Infrared Spectroscopy using an integrating sphere. In this paper, we discuss reasons for choosing this methodology, optimization of quantification conditions and potential applications for the technique. The volume of lubricant solution applied to the ball gives better correlation to the IR intensity than does the weight.
Design considerations in mechanical face seals for improved performance. II - Lubrication

Science.gov (United States)

Ludwig, L. P.; Greiner, H. F.

1977-01-01

The importance of sealing technology in the U.S. industrial chemical-orientated society in regard to maintenance and environmental contamination is pointed out. It is stated that seal performance (leakage, life) is directly related to seal lubrication, which is a mechanism not well understood. Current thinking in regard to seal lubrication is reviewed, the effect of energy dissipation in the thin lubricating film separating the sealing faces is pointed out, and the results of vaporization due to heating are illustrated. Also, hydrodynamic lubrication is reviewed, and an inherent tendency for the seal to operate with angular misalignment is pointed out. Recent work on hydrostatic effects is summarized and the conditions for seal instability are discussed. Four different modes of seal lubrication are postulated with the mode type being a strong function of speed and pressure.
Influence of Workpiece Surface Topography on the Mechanisms of Liquid Lubrication in Strip Drawing

DEFF Research Database (Denmark)

Shimizu, I; Andreasen, Jan Lasson; Bech, Jakob Ilsted

2001-01-01

The workpiece surface topography is an important factor controlling the mechanisms of lubrication in metal forming processes. In the present work, the microscopic lubrication mechanisms induced by lubricant trapped in pockets of the surface in strip drawing are studied. The experiments are perfor......The workpiece surface topography is an important factor controlling the mechanisms of lubrication in metal forming processes. In the present work, the microscopic lubrication mechanisms induced by lubricant trapped in pockets of the surface in strip drawing are studied. The experiments...
Surface effects in adhesion, friction, wear, and lubrication

National Research Council Canada - National Science Library

Buckley, Donald H

1981-01-01

... for carbon bodies to improve their wear resistance in high altitude aircraft generator applications. Basic researchers found that moisture in the carbon was critical t o its lubrication. Therefore, the presence of moisture o n the surface of the carbon was important. With it present, the carbon lubricated very effectively and very low wear was ...
Direct observation of lubricant additives using tomography techniques

Energy Technology Data Exchange (ETDEWEB)

Chen, Yunyun [Department of Materials Science and Engineering, Texas A& M University, College Station, Texas 77843 (United States); Sanchez, Carlos [Mechanical Engineering, Texas A& M University, College Station, Texas 77843 (United States); Parkinson, Dilworth Y. [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Liang, Hong, E-mail: hliang@tamu.edu [Department of Materials Science and Engineering, Texas A& M University, College Station, Texas 77843 (United States); Mechanical Engineering, Texas A& M University, College Station, Texas 77843 (United States)

2016-07-25

Lubricants play important roles in daily activities such as driving, walking, and cooking. The current understanding of mechanisms of lubrication, particularly in mechanical systems, has been limited by the lack of capability in direct observation. Here, we report an in situ approach to directly observe the motion of additive particles in grease under the influence of shear. Using the K-edge tomography technique, it is possible to detect particular additives in a grease and observe their distribution through 3D visualization. A commercial grease as a reference was studied with and without an inorganic additive of Fe{sub 3}O{sub 4} microparticles. The results showed that it was possible to identify these particles and track their movement. Under a shear stress, Fe{sub 3}O{sub 4} particles were found to adhere to the edge of calcium complex thickeners commonly used in grease. Due to sliding, the grease formed a film with increased density. This approach enables in-line monitoring of a lubricant and future investigation in mechanisms of lubrication.

Prediction of refrigerant absorption and onset of natural convection in lubricant oil

Energy Technology Data Exchange (ETDEWEB)

Barbosa, Jader R.; Marcelino Neto, Moises A. [Department of Mechanical Engineering, Federal University of Santa Catarina, Florianopolis, SC 88040900 (Brazil); Thoma, Stefan M. [Department of Mechanical and Process Engineering, Swiss Federal Institute of Technology, Sonneggstrasse 3, 8092 Zurich (Switzerland)

2008-11-15

Refrigerant absorption and mixing in lubricant oil are important in the design of refrigeration compressors and refrigeration systems. Experimental work is reported on absorption of R-134a vapour through the top interface of an initially stagnant layer of pure lubricant oil. Since the liquid refrigerant is heavier than the oil, mixing is enhanced due to natural mass convection. In the present paper, the behaviour of the liquid temperature during absorption is described based on measurements carried out in a test rig consisting of a transparent 70 mm ID, 150 mm long, vertical glass tube through which absorption can be directly observed. Transient liquid temperatures were measured at three different heights in the test section (two in the vapour, one in the liquid). The experimental work is complemented by a theoretical analysis of the critical time for the onset of mass transfer induced Rayleigh instability. The model is based on a critical mass transfer Rayleigh number criterion widely reported in the literature and takes into account the variation of physical properties in the liquid layer. The critical time for the onset of natural mass convection increases with decreasing system pressure as a result of a lower equilibrium concentration at the vapour-liquid interface. (author)
Improving the Friction Durability of Magnetic Head-Disk Interfaces by Thin Lubricant Films

Directory of Open Access Journals (Sweden)

Shojiro Miyake

2016-01-01

Full Text Available Nanowear and viscoelasticity were evaluated to study the nanotribological properties of lubricant films of Z-tetraol, D-4OH, and A20H, including their retention and replenishment properties. For A20H and thick Z-tetraol-coated disks, the disk surface partially protrudes, and the phase lag (tan⁡δ increases with friction. This result is consistent with replenishment of the lubricant upon tip sliding. For the D-4OH-coated disk, the tan⁡δ value decreases with tip sliding, similar to the case for the unlubricated disk. The durability of the lubricant-coated magnetic disks was then evaluated by load increase and decrease friction tests. The friction force of the unlubricated disk rapidly increases after approximately 30 reciprocating cycles, regardless of the load. The lubrication state can be estimated by mapping the dependence of friction coefficient on the reciprocating cycle number and load. The friction coefficient can be classified into one of four areas. The lowest friction area constitutes fluid lubrication. The second area constitutes the transition to mixed lubrication. The third area constitutes boundary lubrication. The highest friction of the fourth area results from surface fracture. The boundary lubricating area of the A20H lubricant was wide, because of its good retention and replenishment properties.
On the energy economics of air lubrication drag reduction

Directory of Open Access Journals (Sweden)

Simo A. Mäkiharju

2012-12-01

Full Text Available Air lubrication techniques for frictional drag reduction on ships have been proposed by numerous researchers since the 19th century. However, these techniques have not been widely adopted as questions persist about their drag reduction performance beyond the laboratory, as well as energy and economic cost-benefit. This paper draws on data from the literature to consider the suitability of air lubrication for large ocean going and U.S. Great Lakes ships, by establishing the basic energy economic calculations and presenting results for a hypothetical air lubricated ship. All the assumptions made in the course of the analysis are clearly stated so that they can be refined when considering application of air lubrication to a specific ship. The analysis suggests that, if successfully implemented, both air layer and partial cavity drag reduction could lead to net energy savings of 10 to 20%, with corresponding reductions in emissions.
Fe-Modeling Of Starved Hydrodynamic Lubrication With Free Surface Effects

DEFF Research Database (Denmark)

Poulios, Konstantinos; Vølund, Anders; Klit, Peder

2017-01-01

This work concerns a new finite-element formulation for solving hydrody-namic lubrication problems that include partially flooded regions, where the lubricant film behavior is governed by free surface flow....
Universal water-dilutable inhibited protective lubricants

International Nuclear Information System (INIS)

Mamtseva, M.V.; Kardash, N.V.; Latynina, M.B.

1993-01-01

In the interest of environmental protection, improvement of working conditions, and reduced fire hazard in production operations, water-based protective lubricants are now available in a wide assortment, and the production volume has increased greatly. The term water-dilutable inhibited protective lubricants (WDIPL) means water-soluble, water-emulsifiable, or water-dispersible products with the dual function of reducing friction and wear and protecting metal surfaces against corrosion for specified periods of time. According to the standard Unified System of Protection Against Corrosion and Aging (COST 9.103-78), WDIPLs are classed as products for the temporary corrosion protection of metals and end-items. In the general class of WDIPLs one can identify water-dilutable combination corrosion inhibitors, film-forming inhibited petroleum compositions (FIPC-d), detergent-preservative fluids, operational-preservative lubricating-cooling process compounds (ICPC), and, finally, universal multifunctional products. Combined corrosion inhibitors may consist of water-soluble organic and inorganic compounds; water/oil and oil-soluble surfactants - corrosion inhibitors of the chemisorption type or donor and/or acceptor types; shielding inhibitors of the adsorption type; and fast-acting water-displacing components. 23 refs
Tribological characteristic enhancement effects by polymer thickened oil in lubricated sliding contacts

Science.gov (United States)

Pratomo, Ariawan Wahyu; Muchammad, Tauviqirrahman, Mohammad; Jamari, Bayuseno, Athanasius P.

2016-04-01

Polymer thickened oils are the most preferred materials for modern lubrication applications due to their high shear. The present paper explores a lubrication mechanism in sliding contact lubricated with polymer thickened oil considering cavitation. Investigations are carried out by using a numerical method based on commercial CFD (computational fluid dynamic) software ANSYS for fluid flow phenomenon (Fluent) to assess the tribological characteristic (i.e. hydrodynamic pressure distribution) of lubricated sliding contact. The Zwart-Gerber-Belamri model for cavitation is adopted in this simulation to predict the extent of the full film region. The polymer thickened oil is characterized as non-Newtonian power-law fluid. The simulation results show that the cavitation lead lower pressure profile compared to that without cavitation. In addition, it is concluded that the characteristic of the lubrication performance with polymer thickened oil is strongly dependent on the Power-law index of lubricant.
Lubrication analysis of the journal bearing in the main coolant pump of SMART

International Nuclear Information System (INIS)

Lee, J. S.; Park, J. S.; Kim, J. H.; Kim, J. I.; Jang, M. H.

2000-01-01

Special type journal bearings are installed in the main coolant pump for SMART to support the rotating shaft with proper lubrication. The canned motor type main coolant pumps are arranged vertically on the reactor vessel. The MCP bearings are lubricated with water without external lubricating oil supply. Long bearing with vertical grooves is designed with relatively large bearing clearance to accommodate the long shaft. Lubricational analysis method for journal bearing with vertical grooves in the main coolant pump of SMART is proposed, and lubricational characteristics of the bearings are examined in this paper
A model of synovial fluid lubricant composition in normal and injured joints

Directory of Open Access Journals (Sweden)

M E Blewis

2007-03-01

Full Text Available The synovial fluid (SF of joints normally functions as a biological lubricant, providing low-friction and low-wear properties to articulating cartilage surfaces through the putative contributions of proteoglycan 4 (PRG4, hyaluronic acid (HA, and surface active phospholipids (SAPL. These lubricants are secreted by chondrocytes in articular cartilage and synoviocytes in synovium, and concentrated in the synovial space by the semi-permeable synovial lining. A deficiency in this lubricating system may contribute to the erosion of articulating cartilage surfaces in conditions of arthritis. A quantitative intercompartmental model was developed to predict in vivo SF lubricant concentration in the human knee joint. The model consists of a SF compartment that (a is lined by cells of appropriate types, (b is bound by a semi-permeable membrane, and (c contains factors that regulate lubricant secretion. Lubricant concentration was predicted with different chemical regulators of chondrocyte and synoviocyte secretion, and also with therapeutic interventions of joint lavage and HA injection. The model predicted steady-state lubricant concentrations that were within physiologically observed ranges, and which were markedly altered with chemical regulation. The model also predicted that when starting from a zero lubricant concentration after joint lavage, PRG4 reaches steady-state concentration ~10-40 times faster than HA. Additionally, analysis of the clearance rate of HA after therapeutic injection into SF predicted that the majority of HA leaves the joint after ~1-2 days. This quantitative intercompartmental model allows integration of biophysical processes to identify both environmental factors and clinical therapies that affect SF lubricant composition in whole joints.
Reactive Fabrication and Effect of NbC on Microstructure and Tribological Properties of CrS Co-Based Self-Lubricating Coatings by Laser Cladding.

Science.gov (United States)

Fang, Liuyang; Yan, Hua; Yao, Yansong; Zhang, Peilei; Gao, Qiushi; Qin, Yang

2017-12-28

The CrS/NbC Co-based self-lubricating composite coatings were successfully fabricated on Cr12MoV steel surface by laser clad Stellite 6, WS₂, and NbC mixed powders. The phase composition, microstructure, and tribological properties of the coatings ware investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectrometer (EDS), as well as dry sliding wear testing. Based on the experimental results, it was found reactions between WS₂ and Co-based alloy powder had occurred, which generated solid-lubricant phase CrS, and NbC play a key role in improving CrS nuclear and refining microstructure of Co-based composite coating during laser cladding processing. The coatings were mainly composed of γ-Co, CrS, NbC, Cr 23 C₆, and CoC x . Due to the distribution of the relatively hard phase of NbC and the solid lubricating phase CrS, the coatings had better wear resistance. Moreover, the suitable balance of CrS and NbC was favorable for further decreasing the friction and improving the stability of the contact surfaces between the WC ball and the coatings. The microhardness, friction coefficient, and wear rate of the coating 4 (Clad powders composed of 60 wt % Stellite 6, 30 wt % NbC and 10 wt % WS₂) were 587.3 HV 0.5 , 0.426, and 5.61 × 10 -5 mm³/N·m, respectively.
Reactive Fabrication and Effect of NbC on Microstructure and Tribological Properties of CrS Co-Based Self-Lubricating Coatings by Laser Cladding

Directory of Open Access Journals (Sweden)

Liuyang Fang

2017-12-01

Full Text Available The CrS/NbC Co-based self-lubricating composite coatings were successfully fabricated on Cr12MoV steel surface by laser clad Stellite 6, WS2, and NbC mixed powders. The phase composition, microstructure, and tribological properties of the coatings ware investigated by means of X-ray diffraction (XRD, scanning electron microscopy (SEM, and energy dispersive spectrometer (EDS, as well as dry sliding wear testing. Based on the experimental results, it was found reactions between WS2 and Co-based alloy powder had occurred, which generated solid-lubricant phase CrS, and NbC play a key role in improving CrS nuclear and refining microstructure of Co-based composite coating during laser cladding processing. The coatings were mainly composed of γ-Co, CrS, NbC, Cr23C6, and CoCx. Due to the distribution of the relatively hard phase of NbC and the solid lubricating phase CrS, the coatings had better wear resistance. Moreover, the suitable balance of CrS and NbC was favorable for further decreasing the friction and improving the stability of the contact surfaces between the WC ball and the coatings. The microhardness, friction coefficient, and wear rate of the coating 4 (Clad powders composed of 60 wt % Stellite 6, 30 wt % NbC and 10 wt % WS2 were 587.3 HV0.5, 0.426, and 5.61 × 10−5 mm3/N·m, respectively.
Testing of environmentally friendly lubricants for sheet metal forming

DEFF Research Database (Denmark)

Bay, Niels; Olsson, David Dam; Andreasen, Jan Lasson

2005-01-01

the authors have especially been involved in the development of a system of test methods for sheet metal forming and in testing of friction and limits of lubrication of new, environmentally friendly lubricants. An overview of the developed tests is presented together with selected results....
Converting an icebreaker from an oil lubricated stern tube bearing system to a seawater lubricated stern tube bearing considering environmental and operating costs

Energy Technology Data Exchange (ETDEWEB)

Ogle, Ken J.; Carter, Craig D. [Thordon Bearings Inc., Burlington, Ontario (Canada)], email: keno@thordonbearings.com, email: craigc@thordonbearings.com

2010-07-01

Icebreakers are prone to oil discharges from the stern tube, and lubricants that are biodegradable elsewhere may not be biodegradable enough in the Arctic and have a toxic effect on the food chain. The vulnerable element is the shaft seal, which must leak a small amount to operate in the first place, and ice milling causes very fast shaft movements that increase the leakage. Also, other objects such as fishing lines seriously compromise the operation of the seal. However, there is an alternative-namely the conversion of oil-lubricated bearings to Thordon COMPAC seawater-lubricated bearings. In this operation, white-metal bearings are replaced with Thordon non-metallic bearings; then, seawater is used as the lubrication and cooling medium. The seawater enters the front part of the stern, passes through the front and aft bearing before returning to the sea. This system totally eliminates the risk of polluting the Arctic ecosystem.
Studies on micro plasto hydrodymic lubrication in metal forming

DEFF Research Database (Denmark)

Bay, Niels; Bech, Jakob Ilsted; Andreasen, Jan Lasson

2002-01-01

The influence of work piece surface topography on friction and lubrication and final surface quality in metal forming operations is well known and has been pointed out by many researchers, see Schey (1983) and Bay and Wanheim (1990). This is especially the case when liquid lubrication is applied...... characterization models the potential entrapment of a lubricant in closed reservoirs is used as a parameter to predetermine the formability of a sheet metal, Steinhoff et al. (1996), Geiger et al. (1997) and Schmoeckel et al. (1997). In experimental studies on friction in metal forming applying the strip drawing...
Rotor Rolling over a Water-Lubricated Bearing

Science.gov (United States)

Shatokhin, V. F.

2018-02-01

The article presents the results of studying the effect of forces associated with secondary damping coefficients (gyroscopic forces) on the development of asynchronous rolling of the rotor over a water-lubricated bearing. The damping forces act against the background of other exciting forces in the rotor-supports system, in particular, the exciting forces of contact interaction between the rotor and bearing. The article considers a rotor resting on supports rubbing against the bearing and the occurrence of self-excited vibration in the form of asynchronous roll-over. The rotor supports are made in the form of plain-type water-lubricated bearings. The plain-type bearing's lubrication stiffness and damping forces are determined using the wellknown algorithms taking into account the physical properties of water serving as lubrication of the bearing. The bearing sliding pair is composed of refractory materials. The lubrication layer in such bearings is thinner than that used in oil-lubricated bearings with white metal lining, and there is no white metal layer in waterlubricated bearings. In case of possible deviations from normal operation of the installation, the rotating rotor comes into direct contact with the liner's rigid body. Unsteady vibrations are modeled using a specially developed software package for calculating the vibration of rotors that rub against the turbine (pump) stator elements. The stiffness of the bearing liner with the stator support structure is specified by a dependence in the force-deformation coordinate axes. In modeling the effect of damping forces, the time moment corresponding to the onset of asynchronous rolling-over with growing vibration amplitudes is used as the assessment criterion. With a longer period of time taken for the rolling-over to develop, it becomes possible to take the necessary measures in response to actuation of the equipment set safety system, which require certain time for implementing them. It is shown that the
Stable solid state reference electrodes for high temperature water chemistry

International Nuclear Information System (INIS)

Jayaweera, P.; Millett, P.J.

1995-01-01

A solid state electrode capable of providing a stable reference potential under a wide range of temperatures and chemical conditions has been demonstrated. The electrode consists of a zirconia or yttria-stabilized zirconia tube packed with an inorganic polymer electrolyte and a silver/silver chloride sensing element. The sensing element is maintained near room temperature by a passive cooling heat sink. The electrode stability was demonstrated by testing it in high temperature (280 C) aqueous solutions over extended periods of time. This reference electrode is useful in many applications, particularly for monitoring the chemistry in nuclear and fossil power plants
Lubrication theory analysis of the permeability of rough-walled fractures

International Nuclear Information System (INIS)

Zimmerman, R.W.; Kumar, S.; Bodvarsson, G.S.

1991-01-01

The flow of a fluid between the rough surfaces of a rock fracture is very complex, due to the tortuous paths followed by the fluid particles. Exact analytical modeling of these flows is made difficult by the irregular geometry of rock fracture surfaces, while full three-dimensional numerical simulations of these flows are as yet still impractical. To overcome the difficulties of working with the three-dimensional Navier-Stokes equations, the simpler Reynolds lubrication equation has sometimes been used to model flow in fractures. This paper focuses on two aspects of lubrication theory. First, lubrication theory is applied to two simplified aperture profiles, sinusoidal and sawtooth, and analytical expressions are found for the permeabilities. These results are then compared with numerical results obtained by solving the lubrication equation for fractures with random surfaces. Secondly, the validity of the lubrication equations for modeling flow in rough fractures is studied by examining higher-order perturbation solutions, as well as numerical solutions, to the Navier-Stokes equations for flow in fractures with sinusoidally-varying apertures. 22 refs., 6 figs
Synthesis and characterization of novel electrolyte materials for intermediate temperature solid oxide fuel cells

International Nuclear Information System (INIS)

Chaubey, Nityanand; Chattopadhyaya, M.C.; Wani, B.N.; Bharadwaj, S.R.

2008-01-01

The high operating temperature of SOFCs using zirconia based electrolyte have several restrictions on materials used as interconnect and sealing and also requires use of expensive ceramics. Lowering the operating temperature of SOFCs to 600-800 deg C will enable to use cheaper materials and reduce the cost of fabrication while keeping the high power density. Lanthanide gallates are considered to be very promising solid electrolytes for intermediate temperature (600-800 deg C) solid oxide fuel cells (IT-SOFCs) due to their high ionic conductivity at lower temperatures. Phase purity of this material is a concern for the researchers for a long time. These materials are prepared at very high temperature (∼1400 deg C), since it is known that at around 1100 deg C, solubilities of Sr and Mg in LaGaO 3 were close to zero. Hence in the present work perovskite oxides of Ln 1-x Sr x Ga 1-y Mg y O 3-δ (Ln= Sm, Gd and x = 0.10, y=0.20) have been prepared by different methods i.e. solid state reaction, gel combustion and co-precipitation methods
Tribology experiment. [journal bearings and liquid lubricants

Science.gov (United States)

Wall, W. A.

1981-01-01

A two-dimensional concept for Spacelab rack 7 was developed to study the interaction of liquid lubricants and surfaces under static and dynamic conditions in a low-gravity environment fluid wetting and spreading experiments of a journal bearing experiments, and means to accurately measure and record the low-gravity environment during experimentation are planned. The wetting and spreading process of selected commercial lubricants on representative surface are to the observes in a near-zero gravity environment.
Noise estimation of oil lubricated journal bearings

International Nuclear Information System (INIS)

Rho, Byoung Hoo; Kim, Kyung Woong

2003-01-01

Noise estimating procedures of oil lubricated journal bearings are presented. Nonlinear analysis of rotor-bearing system including unbalance mass of the rotor is performed in order to obtain acoustical properties of the bearing. Acoustical properties of the bearing are investigated through frequency analysis of the pressure fluctuation of the fluid film calculated from the nonlinear analysis. Noise estimating procedures presented in this paper could aid in the evaluation and understanding of acoustical properties of oil lubricated journal bearings
Friction and wear behaviour of Mo–W doped carbon-based coating during boundary lubricated sliding

Energy Technology Data Exchange (ETDEWEB)

Hovsepian, Papken Eh., E-mail: p.hovsepian@shu.ac.uk [Nanotechnology Centre for PVD Research, HIPIMS Research Centre, Sheffield Hallam University, City Campus, Howard Street, Sheffield S1 1WB (United Kingdom); Mandal, Paranjayee, E-mail: 200712mum@gmail.com [Nanotechnology Centre for PVD Research, HIPIMS Research Centre, Sheffield Hallam University, City Campus, Howard Street, Sheffield S1 1WB (United Kingdom); Ehiasarian, Arutiun P., E-mail: a.ehiasarian@shu.ac.uk [Nanotechnology Centre for PVD Research, HIPIMS Research Centre, Sheffield Hallam University, City Campus, Howard Street, Sheffield S1 1WB (United Kingdom); Sáfrán, G., E-mail: safran.gyorgy@ttk.mta.hu [Institute for Technical Physics and Materials Science, Centre for Energy Research, Hungarian Academy of Sciences, H-1121 Budapest, Konkoly-Thegeut 29-33 (Hungary); Tietema, R., E-mail: rtietema@hauzer.nl [IHI Hauzer Techno Coating B.V., Van Heemskerckweg 22, 5928 LL Venlo (Netherlands); Doerwald, D., E-mail: ddoerwald@hauzer.nl [IHI Hauzer Techno Coating B.V., Van Heemskerckweg 22, 5928 LL Venlo (Netherlands)

2016-03-15

Graphical abstract: - Highlights: • Novel Mo–W–C coating provides extremely low friction (μ ∼ 0.03) in lubricated condition. • Mo–W–C outperforms existing DLCs in terms of low friction, independent of temperature. • Tribochemical reactions govern the wear mechanism of Mo–W–C coating. • The transfer layer contains graphitic carbon and ‘in situ’ formed WS{sub 2} and MoS{sub 2}. • WS{sub 2} and MoS{sub 2} are the key factors facilitating appreciably low friction and wear rate. - Abstract: A molybdenum and tungsten doped carbon-based coating (Mo–W–C) was developed in order to provide low friction in boundary lubricated sliding condition at ambient and at high temperature. The Mo–W–C coating showed the lowest friction coefficient among a number of commercially available state-of-the-art DLC coatings at ambient temperature. At elevated temperature (200 °C), Mo–W–C coating showed a significant reduction in friction coefficient with sliding distance in contrast to DLC coatings. Raman spectroscopy revealed the importance of combined Mo and W doping for achieving low friction at both ambient and high temperature. The significant decrease in friction and wear rate was attributed to the presence of graphitic carbon debris (from coating) and ‘in situ’ formed metal sulphides (WS{sub 2} and MoS{sub 2}, where metals were supplied from coating and sulphur from engine oil) in the transfer layer.

Friction and wear behaviour of Mo–W doped carbon-based coating during boundary lubricated sliding

International Nuclear Information System (INIS)

Hovsepian, Papken Eh.; Mandal, Paranjayee; Ehiasarian, Arutiun P.; Sáfrán, G.; Tietema, R.; Doerwald, D.

2016-01-01

Graphical abstract: - Highlights: • Novel Mo–W–C coating provides extremely low friction (μ ∼ 0.03) in lubricated condition. • Mo–W–C outperforms existing DLCs in terms of low friction, independent of temperature. • Tribochemical reactions govern the wear mechanism of Mo–W–C coating. • The transfer layer contains graphitic carbon and ‘in situ’ formed WS 2 and MoS 2 . • WS 2 and MoS 2 are the key factors facilitating appreciably low friction and wear rate. - Abstract: A molybdenum and tungsten doped carbon-based coating (Mo–W–C) was developed in order to provide low friction in boundary lubricated sliding condition at ambient and at high temperature. The Mo–W–C coating showed the lowest friction coefficient among a number of commercially available state-of-the-art DLC coatings at ambient temperature. At elevated temperature (200 °C), Mo–W–C coating showed a significant reduction in friction coefficient with sliding distance in contrast to DLC coatings. Raman spectroscopy revealed the importance of combined Mo and W doping for achieving low friction at both ambient and high temperature. The significant decrease in friction and wear rate was attributed to the presence of graphitic carbon debris (from coating) and ‘in situ’ formed metal sulphides (WS 2 and MoS 2 , where metals were supplied from coating and sulphur from engine oil) in the transfer layer.
Mixed Lubricated Line Contacts

NARCIS (Netherlands)

Faraon, I.C.

2005-01-01

The present work deals with friction in mixed lubricated line contacts. Components in systems are becoming smaller and due to, for instance power transmitted, partial contact may occur. In industrial applications, friction between the moving contacting surfaces cannot be avoided, therefore it is
Heat Treatment Used to Strengthen Enabling Coating Technology for Oil-Free Turbomachinery

Science.gov (United States)

Edmonds, Brian J.; DellaCorte, Christopher

2002-01-01

The PS304 high-temperature solid lubricant coating is a key enabling technology for Oil- Free turbomachinery propulsion and power systems. Breakthroughs in the performance of advanced foil air bearings and improvements in computer-based finite element modeling techniques are the key technologies enabling the development of Oil-Free aircraft engines being pursued by the Oil-Free Turbomachinery team at the NASA Glenn Research Center. PS304 is a plasma spray coating applied to the surface of shafts operating against foil air bearings or in any other component requiring solid lubrication at high temperatures, where conventional materials such as graphite cannot function.
Prediction of limits of lubrication in strip reduction testing

DEFF Research Database (Denmark)

Olsson, David Dam; Bay, Niels; Andreasen, Jan Lasson

2004-01-01

Pick-up and galling due to lubricant film breakdown is a severe limitation in cold forming of tribologically difficult metals like stainless steel and aluminium. The present paper describes a method of combined experimental and numerical analysis to quantify the limits of lubrication in a dedicated...
Role of lubricants on friction between self-ligating brackets and archwires.

Science.gov (United States)

Leal, Renata C; Amaral, Flávia L B; França, Fabiana M G; Basting, Roberta T; Turssi, Cecilia P

2014-11-01

To evaluate the effect of different lubricants on friction between orthodontic brackets and archwires. Active (Quick, Forestadent) and passive (Damon 3MX, Ormco) self-ligating brackets underwent friction tests in the presence of mucin- and carboxymethylcellulose (CMC)-based artificial saliva, distilled water, and whole human saliva (positive control). Dry friction (no lubricant) was used as the negative control. Bracket/wire samples (0.014 × 0.025 inch, CuNiTi, SDS Ormco) underwent friction tests eight times in a universal testing machine. Two-way analysis of variance showed no significant interaction between bracket type and lubricant (P = .324). Friction force obtained with passive self-ligating brackets was lower than that for active brackets (P Friction observed in the presence of artificial saliva did not differ from that generated under lubrication with natural human saliva, as shown by Tukey test. Higher friction forces were found with the use of distilled water or when the test was performed under dry condition (ie, with no lubricant). Lubrication plays a role in friction forces between self-ligating brackets and CuNiTi wires, with mucin- and CMC-based artificial saliva providing a reliable alternative to human natural saliva.
Friction and Lubrication of Large Tilting-Pad Thrust Bearings

Directory of Open Access Journals (Sweden)

Michał Wasilczuk

2015-04-01

Full Text Available Fluid film bearings have been extensively used in the industry because of their unbeatable durability and extremely low friction coefficient, despite a very low coefficient of friction dissipation of energy being noticeable, especially in large bearings. Lubricating systems of large tilting pad thrust bearings utilized in large, vertical shaft hydrogenerators are presented in this paper. A large amount of heat is generated due to viscous shearing of the lubricant large tilting pad thrust bearings, and this requires systems for forced cooling of the lubricant. In the dominant bath lubrication systems, cooling is realized by internal coolers or external cooling systems, with the latter showing some important advantages at the cost of complexity and also, potentially, lower reliability. Substantial losses in the bearings, reaching 1 MW in extreme cases, are a good motivation for the research and development aimed at reducing them. Some possible methods and their potential efficiency, along with some effects already documented, are also described in the paper.
49 CFR 396.5 - Lubrication.

Science.gov (United States)

2010-10-01

..., DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS INSPECTION, REPAIR, AND MAINTENANCE § 396.5 Lubrication. Every motor carrier shall ensure that each motor vehicle subject to its control is...
WATER-EMULSION LUBRICANTS FOR PRESS-MODES OF CASTING UNDER PRESSURE

Directory of Open Access Journals (Sweden)

A. M. Mihaltsov

2005-01-01

Full Text Available It is shown that for more successful using of wateremulsion lubricants it is necessary to use new lubricating component. One of such component is complex component on the basis of siloxanes.
New lubricant systems for cold and warm forging – advantages and limitations

DEFF Research Database (Denmark)

Bay, Niels

2011-01-01

. The present paper gives an overview of these efforts substituting environmentally hazardous lubricants in cold, warm and hot forging by new, more harmless lubricants. Introduction of these new lubricants, however, has some drawbacks due to lower limits of lubrication leading to risk of pick-up, poor product......The increasing focus on environmental issues and the requirements to establish solutions diminishing the impact on working environment as well as external environment has strongly motivated the efforts to develop new, environmentally friendly tribological systems for metal forming production...
Research into Oil-based Colloidal-Graphite Lubricants for Forging of Al-based Alloys

International Nuclear Information System (INIS)

Petrov, A.; Petrov, P.; Petrov, M.

2011-01-01

The presented paper describes the topical problem in metal forging production. It deals with the choice of an optimal lubricant for forging of Al-based alloys. Within the scope of the paper, the properties of several oil-based colloidal-graphite lubricants were investigated. The physicochemical and technological properties of these lubricants are presented. It was found that physicochemical properties of lubricant compositions have an influence on friction coefficient value and quality of forgings.The ring compression method was used to estimate the friction coefficient value. Hydraulic press was used for the test. The comparative analysis of the investigated lubricants was carried out. The forging quality was estimated on the basis of production test. The practical recommendations were given to choose an optimal oil-based colloidal-graphite lubricant for isothermal forging of Al-based alloy.
Chameleon Coatings: Adaptive Surfaces to Reduce Friction and Wear in Extreme Environments

Science.gov (United States)

Muratore, C.; Voevodin, A. A.

2009-08-01

Adaptive nanocomposite coating materials that automatically and reversibly adjust their surface composition and morphology via multiple mechanisms are a promising development for the reduction of friction and wear over broad ranges of ambient conditions encountered in aerospace applications, such as cycling of temperature and atmospheric composition. Materials selection for these composites is based on extensive study of interactions occurring between solid lubricants and their surroundings, especially with novel in situ surface characterization techniques used to identify adaptive behavior on size scales ranging from 10-10 to 10-4 m. Recent insights on operative solid-lubricant mechanisms and their dependency upon the ambient environment are reviewed as a basis for a discussion of the state of the art in solid-lubricant materials.
Increased production of naphtenic lubricants using more active catalysts; Aumento da producao de lubrificantes naftenicos usando catalisadores mais ativos

Energy Technology Data Exchange (ETDEWEB)

Fontes, Anita Eleonora F.; Lima, Anie Daniela M.; Figueiredo, Joao B.; Nogueira, Wlamir S.; Zotin, Jose L. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

2008-07-01

PETROBRAS produces lubricant base oil in three of its refineries: Duque de Caxias (REDUC), Landulpho Alves (RLAM) and Lubricants and Derivatives of Petroleum of Northeast (LUBNOR). LUBNOR, which began its operation in 1998, is the only refinery that produces naphtenic lubricant base oils with a current capacity of 60.000 m{sup 3}/year. It processes Brazilian naphtenic crudes in a vacuum distillation unit to produce distillates, which are then fed in to a hydrotreatment unit (HDT). This HDT unit processes 170 m{sup 3}/day to obtain base oils NH-10, NH-20, NH-140 and ISOVOLT. In 2007, an evaluation study of new catalysts was made for this unit at PETROBRAS Research Center (CENPES) aiming to increase the production capacity of the HDT unit. The concept was based on increasing the catalytic activity in the HTD unit by testing new catalysts and operating conditions in a pilot-plant unit. The results obtained were very promising showing that a selected catalyst achieved the normal production rate maintaining the same high quality product at a temperature lower than the conventional process. Alternatively, a 77% increase in the throughput capacity was achieved when the normal reaction temperature was applied to this selected catalyst. (author)
Thickened water-based hydraulic fluid with reduced dependence of viscosity on temperature

Energy Technology Data Exchange (ETDEWEB)

Deck, C. F.

1985-01-01

Improved hydraulic fluids or metalworking lubricants, utilizing mixtures of water, metal lubricants, metal corrosion inhibitors, and an associative polyether thickener, have reduced dependence of the viscosity on temperature achieved by the incorporation therein of an ethoxylated polyether surfactant.
Progress in Tribological Properties of Nano-Composite Hard Coatings under Water Lubrication

Directory of Open Access Journals (Sweden)

Qianzhi Wang

2017-02-01

Full Text Available The tribological properties, under water-lubricated conditions, of three major nano-composite coatings, i.e., diamond-like carbon (DLC or a-C, amorphous carbon nitride (a-CNx and transition metallic nitride-based (TiN-based, CrN-based, coatings are reviewed. The influences of microstructure (composition and architecture and test conditions (counterparts and friction parameters on their friction and wear behavior under water lubrication are systematically elucidated. In general, DLC and a-CNx coatings exhibit superior tribological performance under water lubrication due to the formation of the hydrophilic group and the lubricating layer with low shear strength, respectively. In contrast, TiN-based and CrN-based coatings present relatively poor tribological performance in pure water, but are expected to present promising applications in sea water because of their good corrosion resistance. No matter what kind of coatings, an appropriate selection of counterpart materials would make their water-lubricated tribological properties more prominent. Currently, Si-based materials are deemed as beneficial counterparts under water lubrication due to the formation of silica gel originating from the hydration of Si. In the meantime, the tribological properties of nano-composite coatings in water could be enhanced at appropriate normal load and sliding velocity due to mixed or hydrodynamic lubrication. At the end of this article, the main research that is now being developed concerning the development of nano-composite coatings under water lubrication is described synthetically.
The problems of material pairs under the specific conditions of high-temperature reactors

International Nuclear Information System (INIS)

Schoening, J.

1981-01-01

This dissertation gives a detailed descirption of the problems of friction and solid lubrication of slide and ball bearings under HTR conditions. The first part is concerned with an analysis of established approaches for determining the friction factor and the development of a mathematical model on this basis, taking particular account of the following parameters. (1) Surface characteristics (peak-to-valley height, pressure angles of roughness elevations) and, (2) material properties of the friction partner (ductility, brittleness, crystal structure). The formula for friction factor thus arrived at incorporates the microscopic and sub-microscopic influence of the surface grain structure. In addition, the effects of elastic and plastic properties at the region of contact was studied. The derived equation is used to characterise frictional properties and enables a suitable and economic friction pair to be selected. The second part deals with the application of solid lubrication and the effect of the solid lubricant film on the mechanicsm and kinematics of ball bearings. In the final part of this investigation an evaluation of experimental results is carried out on the basis of the preceding theoretical studies in order to confirm the theoretical approach and to provide information of practical use on limits of application, cost details and aids to construction. (orig./IHOE) [de
A comparison of the lubrication behavior of whey protein model foods using tribology in linear and elliptical movement.

Science.gov (United States)

Campbell, Caroline L; Foegeding, E Allen; van de Velde, Fred

2017-08-01

Lubrication is an important factor in the sensory evaluation of food products. Tribology provides a theoretical framework and instrumental methods for evaluating frictional properties between two moving surfaces and the lubrication behavior of products between these surfaces. Relating frictional measurements to sensory properties detected during oral processing requires careful and pertinent choices in surface materials and testing conditions. The aims of this study were to investigate: (a) differences in lubrication behavior of a range of food textures and (b) the differences between linear and elliptical movement and added saliva to understand the contribution of food structure to friction. Six whey protein model food samples, ranging in texture from fluid to semisolid to soft solid, were analyzed using a pin on disk tribometer to determine the coefficient of friction (COF) across a range of sliding speeds. The samples were analyzed in their initial form and post-oral processing (n = 4) in both linear and elliptical movements. Elliptical movement slightly decreased coefficients of friction and extended the shape of the friction curve. Increases in test food viscosity decreased the COF but differences in viscosity were not apparent when test foods were mixed with saliva. Data correction for viscosity shifted the friction curves horizontally, indicating that lubrication had a greater impact upon friction than viscosity. This study provides initial insights for further comparison of linear and elliptical movement with a variety of sample compositions. Sensory perception of smoothness and creaminess are often major contributors to overall hedonic food liking and are a major reason why products high in fat and sugar are more highly preferred over other foods. These parameters are influenced by friction and lubrication between the tongue, palate, teeth, food products, and saliva during oral processing. Tribology provides an instrumental method to evaluate friction
Engineered Joint Lubrication for OA Prevention and Treatment

Science.gov (United States)

2015-09-01

that work together with liquid lubricants to achieve low-friction systems. Lubrication between tissues is also important to maintain low-friction...movement within a number of biological systems, including the pleural cavity, the surface of the eye, visceral organs, and diarthroidal joints3. In...purified using reverse-phase high-performance liquid chromatography (C18 Grace-Vydac column) on a water/acetonitrile gradient. Purified peptides were
Lubricated immersed boundary method in two dimensions

Science.gov (United States)

Fai, Thomas G.; Rycroft, Chris H.

2018-03-01

Many biological examples of fluid-structure interaction, including the transit of red blood cells through the narrow slits in the spleen and the intracellular trafficking of vesicles into dendritic spines, involve the near-contact of elastic structures separated by thin layers of fluid. Motivated by such problems, we introduce an immersed boundary method that uses elements of lubrication theory to resolve thin fluid layers between immersed boundaries. We demonstrate 2nd-order accurate convergence for simple two-dimensional flows with known exact solutions to showcase the increased accuracy of this method compared to the standard immersed boundary method. Motivated by the phenomenon of wall-induced migration, we apply the lubricated immersed boundary method to simulate an elastic vesicle near a wall in shear flow. We also simulate the dynamics of a vesicle traveling through a narrow channel and observe the ability of the lubricated method to capture the vesicle motion on relatively coarse fluid grids.
Lubricant depletion under various laser heating conditions in Heat Assisted Magnetic Recording (HAMR)

Science.gov (United States)

Xiong, Shaomin; Wu, Haoyu; Bogy, David

2014-09-01

Heat assisted magnetic recording (HAMR) is expected to increase the storage areal density to more than 1 Tb/in2 in hard disk drives (HDDs). In this technology, a laser is used to heat the magnetic media to the Curie point (~400-600 °C) during the writing process. The lubricant on the top of a magnetic disk could evaporate and be depleted under the laser heating. The change of the lubricant can lead to instability of the flying slider and failure of the head-disk interface (HDI). In this study, a HAMR test stage is developed to study the lubricant thermal behavior. Various heating conditions are controlled for the study of the lubricant thermal depletion. The effects of laser heating repetitions and power levels on the lubricant depletion are investigated experimentally. The lubricant reflow behavior is discussed as well.
Development test of multiple die with hydraulic compensation and auto lubrication

International Nuclear Information System (INIS)

Chen Mengyou; Zhang Xichang; Zhu Ninghua; Liu Zichang

1988-05-01

Multiple die with hydraulic compensating device adopts the design of multidies gathering in a common grease cavity, using high temperature lubricating grease as the pressure compensating medium. According to Pascal's Law, each die will receive equal pressure during the process of pressing. Such device changes the equi-volume pressing mode of single mechanical die to equipressure pressing mode of multiple die in nuclear fuel element production, thus improves the quality and raises the quantity of nuclear fuel and powder ceramic products, giving a better economic benefit

INVESTIGATION OF FLOW BEHAVIOR IN MINIMUM QUANTITY LUBRICATION NOZZLE FOR END MILLING PROCESSES

OpenAIRE

M.S. Najiha; M.M.Rahman; A.R. Yusoff; K. Kadirgama

2012-01-01

Minimum quantity lubrication (MQL) is a sustainable manufacturing technique that has replaced conventional flooded lubrication methods and dry machining. In the MQL technique, the lubricant is sprayed onto the friction surfaces through nozzles through small pneumatically-operated pumps. This paper presents an investigation into the flow behavior of the lubricant and air mixture under certain pressures at the tip of a nozzle specially designed for MQL. The nozzle used is an MQL stainless steel...
Fatty acid methyl esters, carbon nanotubes and carbon nanowalls coatings such as lubricity improvers of low sulfur diesel fuels

Energy Technology Data Exchange (ETDEWEB)

Cursaru, Diana Luciana; Tanasescu, Constantin [Petroleum-Gas Univ. of Ploiesti (Romania); Vizireanu, Sorin [National Institute for Laser, Plasma and Radiation Physics (Romania)

2013-06-01

In this study the lubricity of diesel fuel was restored by different methods, firstly by classic addition of fatty acid methyl esters or by dispersing carbon nanotubes into diesel fuels and secondly, by protecting the metallic surfaces which are in the direct contact to the low sulfur diesel fuel, by application of solid carbon nanowalls coatings synthesized by radiofrequency plasma beam deposition. The fatty acid methyl esters were prepared by transesterification of the sun flower oil in the presence of methanol. The carbon nanotubes were synthesized by CO disproportionation method and were characterized by RAMAN spectroscopy and high resolution transmission electron microscopy (TEM). The CNWs layers, before the friction tests, were examined by scanning electron microscopy (SEM), atomic force microscopy (AFM) and Raman spectroscopy, while the wear on the steel balls was investigated by optical microscopy of the HRRT apparatus and the wear track on the steel disk was investigated by SEM, AFM and profilometry. The lubricity was measured using the High Frequency Reciprocating Rig (HFRR) method. It has been found that CNWs layers exhibit a lubricating potential for the rubbed surfaces in the presence of low sulfur diesel fuels. Tribological analyses of various carbon materials revealed that the friction coefficient of carbon nanowalls is close to the values obtained for graphite. (orig.)
Use of high-molecular compounds in plastic lubricants for geological exploratory drilling

Energy Technology Data Exchange (ETDEWEB)

Smyk, Z.I.; Kuz' michev, S.P.; Mnishchenko, V.G.; Smertenko, M.I.

1982-01-01

The existing lubricants in the series KAVS (OST 81-4-70) do not correspond to the conditions of high-rotational diamond drilling for a number of operating properties. Results are presented of studying the hydrated calcium lubricants with high molecular additives (polyisobutylene KP-10, polyethylene of high density of low pressure and atactic propylene in a quantity of 1-6%) improving their operating properties. Selection of the additives is governed by their compatability with the base and the capacity to improve the adhesion-cohesion properties with relative constancy of other characteristics. As a result of the studies it was established that the use in the lubricant of polymers of the carbon-chain type of amorphous structure in a quantity of 1-2% depending on the molecular weight noticeably improves the stickiness, resistance to erosion by water, colloidal stability, and lubricant properties. When they are added in a large quantity, a sharp weakening of the lubricants is observed and in individual cases, formation of unstable systems. Polymers of the hetero-chain type because of the presence of polar groups are highly effective adhesives. Protective and packing lubricants are developed which contain rubbers. Alkyl-phenol-amine resins (octophor-N), the bottoms from the production of phenol formaldehyde resin, rosin and lignite wax introduced at the stage of cooling have a positive effect on the lubricant properties. The best operating properties with satisfactory other indicators (viscosity, colloidal stability, antiwear properties) are found in the samples containing polyisobutylene KP-10, lignite wax and rosin. Operating tests of an experimental batch of this lubricant under conditions of real drilling indicated that its use as compared to KEVS-45 makes it possible to increase the drilling rate by 40%, reduce the outlays of power to 50%, reduce the service time and the outlays of energy resources for applying the lubricant layer to the pipe surface.
Linear and Non-Linear Control Techniques Applied to Actively Lubricated Journal Bearings

DEFF Research Database (Denmark)

Nicoletti, Rodrigo; Santos, Ilmar

2003-01-01

The main objectives of actively lubricated bearings are the simultaneous reduction of wear and vibration between rotating and stationary machinery parts. For reducing wear and dissipating vibration energy until certain limits, one can count with the conventional hydrodynamic lubrication. For furt......The main objectives of actively lubricated bearings are the simultaneous reduction of wear and vibration between rotating and stationary machinery parts. For reducing wear and dissipating vibration energy until certain limits, one can count with the conventional hydrodynamic lubrication....... For further reduction of shaft vibrations one can count with the active lubrication action, which is based on injecting pressurised oil into the bearing gap through orifices machined in the bearing sliding surface. The design and efficiency of some linear (PD, PI and PID) and non-linear controllers, applied...... vibration reduction of unbalance response of a rigid rotor, where the PD and the non-linear P controllers show better performance for the frequency range of study (0 to 80 Hz). The feasibility of eliminating rotor-bearing instabilities (phenomena of whirl) by using active lubrication is also investigated...
Fabrication of cathode supported tubular solid oxide electrolysis cell for high temperature steam electrolysis

Energy Technology Data Exchange (ETDEWEB)

Shao, Le; Wang, Shaorong; Qian, Jiqin; Xue, Yanjie; Liu, Renzhu

2011-01-15

In recent years, hydrogen has been identified as a potential alternative fuel and energy carrier for the future energy supply. Water electrolysis is one of the important hydrogen production technologies which do not emit carbon dioxide. High temperature steam electrolysis (HTSE) consumes even less electrical energy than low temperature water electrolysis. Theoretically, HTSE using solid oxide electrolysis cells (SOEC) can efficiently utilize renewable energy to produce hydrogen, and it is also possible to operate the SOEC in reverse mode as the solid oxide fuel cell (SOFC) to produce electricity. Tubular SOFC have been widely investigated. In this study, tubular solid oxide cells were fabricated by dip-coating and cosintering techniques. In SOEC mode, results suggested that steam ratio had a strong impact on the performance of the tubular cell; the tubular SOEC preferred to be operated at high steam ratio in order to avoid concentration polarization. The microstructure of the tubular SOEC should therefore be optimized for high temperature steam electrolysis.
The Stability of Lubricant Oil Acidity of Biogas Fuelled Engine due to Biogas Desulfurization

Science.gov (United States)

Gde Tirta Nindhia, Tjokorda; Wayan Surata, I.; Wardana, Ari

2017-05-01

This research is established for the purpose of the understanding the stability of the acidity of lubricant oil in biogas fuelled engine due to the absence of hydrogen sulfide (H2S). As was recognized that other than Methane (CH4), there are also other gas impurities in the biogas such as carbon dioxide (CO2), hydrogen sulfide (H2S), moisture (H2O) and ammonia (NH3). Due to H2S contents in the biogas fuel, the engine was found failure. This is caused by corrosion in the combustion chamber due to increase of lubricant acidity. To overcome this problem in practical, the lubricant is increased the pH to basic level with the hope will be decrease to normal value after several time use. Other method is by installing pH measurement sensor in the engine lubricant so that when lubricant is known turn to be acid, then lubricant replacement should be done. In this research, the effect of biogas desulfurization down to zero level to the acidity of lubricant oil in the four stroke engine was carried out with the hope that neutral lubrication oil to be available during running the engine. The result indicates that by eliminating H2S due desulfurization process, effect on stability and neutrality of pH lubricant. By this method the engine safety can be obtained without often replacement the lubricant oil.
Effect of load on the tribological properties of hypereutectic Al-Si alloy under boundary lubrication conditions

Science.gov (United States)

Kumar, Parveen; Wani, M. F.

2017-11-01

Researchers reported that the IC engine components (piston, cylinder liner etc) fail due to the friction losses (~45%) and wear losses (~25-40%). So the demand of light weight, low friction and wear resistance alloys increases day by day, which reduces the emission and increases the efficiency of the IC engine. In this connection, tribological tests on hypereutectic Al-25Si alloy were performed using a ball-on-disk configuration under dry and lubricated sliding conditions. Hypereutectic Al-25Si alloy was prepared by rapid solidification process with T6 condition. T6 condition improves the friction, wear and mechanical properties of the alloy. Friction coefficient and wear rate of the alloy was measured under high loads ranging from 100 to 300 N. It was found that the friction coefficient (COF) and wear rate of hypereutectic Al-25Si alloy/steel tribo pair increased with increase in load. Significant reduction in COF and wear rate was accomplished with SAE20W50 engine oil and Si particles act as solid lubricant. Optical microscope, 3D surface profilometer and scanning electron microscope (SEM) coupled with an energy dispersive spectrometer (EDS) were used for characterization the worn surface morphologies. The morphology, size and distribution of high Si particles due to its fabrication process caused the improvements in COF and wear rate under lubricated conditions. Adhesive wear, abrasive wear and plastic deformation acted as the dominant wear mechanism for hypereutectic Al-25Si alloy.
Adaptive system of supplying lubricant to the internal combustion engine

Science.gov (United States)

Barylnikova, E. P.; Kulakov, A. T.; Kulakov, O. A.

2017-09-01

This paper assesses the impact of reducing the pressure in the lubrication system on the failures of the crankshaft bearings. The method of adapting lubricating system of the diesel engine as the wear in operation and depending on the operation modes.
Deformation and friction of MoS2 particles in liquid suspensions used to lubricate sliding contact

International Nuclear Information System (INIS)

Sahoo, Rashmi R.; Biswas, Sanjay K.

2010-01-01

Tribology of a well known solid lubricant molybdenum disulphide is studied here in water and oil medium, over a large range of contact dimensions. Lateral force microscopy is used to identify the deformation modes; intra-crystalline slip, plastic grooving, fragmentation and fracture, of single particles. The medium and agglomeration were found to dictate the deformation mode. Steel on steel tribology lubricated by suspensions of these particles in liquid media was conducted over a range of contact pressure and sliding velocity. A scrutiny of the frictional data with the aid of Raman spectroscopy to identify the transfer film, suggested that the particle size, as it is at contact, is an important tribological parameter. Ultrasonication of the suspension and dispersion of the particle by surfactants were used to control the apriori particle size fed into the suspension. Correspondence of friction data of the gently sonicated suspension with that of the ultrasonicated suspension with dispersants indicated the importance of liquid ingestion by these particles as it controls their mode of deformation and consequent tribology.
Microstructure, Mechanical and Tribological Properties of Ag/Bi2Sr2CaCu2O x Self-lubricating Composites

Science.gov (United States)

Tang, Hua; Zhang, Du; Wang, Yuqi; Zhang, Yi; Ji, Xiaorui; Song, Haojie; Li, Changsheng

2014-01-01

Ag/Bi2Sr2CaCu2O x self-lubricating composites were successfully fabricated by a facile powder metallurgy method. The structure and morphology of the as-synthesized composites and the worn surface after tribometer testing are characterized by using X-ray diffraction and scanning electron microscopy together with energy dispersive spectrometry. The results indicated that self-lubricating composites are composed of superconductor phase and Ag phase. Moreover, the effects of Ag on mechanical and tribological properties of the novel composites were investigated. The friction test results showed that the friction coefficient of the pure Bi2212 against stainless steel is about 0.40 at ambient temperature and abruptly decreases to about 0.17 when the temperature is cooled to 77 K. The friction coefficients of the composites from room temperature to high temperature were lower and more stable than those of pure Bi2Sr2CaCu2O x . When the content of Ag is 10 wt.%, the Ag/Bi2Sr2CaCu2O x composites exhibited excellent tribological performance, the improved tribological properties are attributed to the formation of soft metallic Ag films at the contacted zone of the composites.
Effects of heat treatment on microstructure and mechanical properties of Ni60/h-BN self-lubricating anti-wear composite coatings on 304 stainless steel by laser cladding

Science.gov (United States)

Lu, Xiao-Long; Liu, Xiu-Bo; Yu, Peng-Cheng; Zhai, Yong-Jie; Qiao, Shi-Jie; Wang, Ming-Di; Wang, Yong-Guang; Chen, Yao

2015-11-01

Laser clad Ni60/h-BN self-lubricating anti-wear composite coating on 304 stainless steel were heat treated at 600 °C (stress relief annealing) for 1 h and 2 h, respectively. Effects of the phase compositions, microstructure, microhardness, nano-indentation and tribological properties of the composite coatings with and without heat treatment had been investigated systemically. Results indicated that three coatings mainly consist of the matrix γ-(Ni, Fe) solid solution, the CrB ceramic phases and the h-BN lubricating phases. The maximum microhardness of the coatings was first increased from 667.7 HV0.5 to 765.0 HV0.5 after heat treatment for 1 h, and then decreased to 698.3 HV0.5 after heat treatment for 2 h. The hardness of γ-(Ni, Fe) solid solution without heat treatment and after heat treatment 1 h and 2 h were 5.09 GPa, 7.20 GPa and 3.77 GPa, respectively. Compared with the coating without heat treatment, the friction coefficients of the coating after heat treatment were decreased obviously. Effects of the heat treatment time on friction coefficient were negligible, but were significant on wear volume loss. Comparatively speaking, the laser clad self-lubricating anti-wear composite coating after heat treatment for 1 h presented the best anti-wear and friction reduction properties.
Tailorable Burning Behavior of Ti14 Alloy by Controlling Semi-Solid Forging Temperature.

Science.gov (United States)

Chen, Yongnan; Yang, Wenqing; Zhan, Haifei; Zhang, Fengying; Huo, Yazhou; Zhao, Yongqing; Song, Xuding; Gu, Yuantong

2016-08-16

Semi-solid processing (SSP) is a popular near-net-shape forming technology for metals, while its application is still limited in titanium alloy mainly due to its low formability. Recent works showed that SSP could effectively enhance the formability and mechanical properties of titanium alloys. The processing parameters such as temperature and forging rate/ratio, are directly correlated with the microstructure, which endow the alloy with different chemical and physical properties. Specifically, as a key structural material for the advanced aero-engine, the burn resistant performance is a crucial requirement for the burn resistant titanium alloy. Thus, this work aims to assess the burning behavior of Ti14, a kind of burn resistant alloy, as forged at different semi-solid forging temperatures. The burning characteristics of the alloy are analyzed by a series of burning tests with different burning durations, velocities, and microstructures of burned sample. The results showed that the burning process is highly dependent on the forging temperature, due to the fact that higher temperatures would result in more Ti₂Cu precipitate within grain and along grain boundaries. Such a microstructure hinders the transport of oxygen in the stable burning stage through the formation of a kind of oxygen isolation Cu-enriched layer under the burn product zone. This work suggests that the burning resistance of the alloy can be effectively tuned by controlling the temperature during the semi-solid forging process.
Lubrication in cold rolling : Numerical simulation using multigrid techniques

NARCIS (Netherlands)

Lugt, Pieter Martin

1992-01-01

In the cold rolling process a lubricant is applied on the rolls and/or the strip material. Due to the velocities of the rolls and the strip, part of the lubricant is sheared into the contact causing, amongst others, a reduction of the friction. In this thesis a physical-mathematical model is
Organic-Modified Silver Nanoparticles as Lubricant Additives.

Science.gov (United States)

Kumara, Chanaka; Luo, Huimin; Leonard, Donovan N; Meyer, Harry M; Qu, Jun

2017-10-25

Advanced lubrication is essential in human life for improving mobility, durability, and efficiency. Here we report the synthesis, characterization, and evaluation of two groups of oil-suspendable silver nanoparticles (NPs) as candidate lubricant additives. Two types of thiolated ligands, 4-(tert-butyl)benzylthiol (TBBT) and dodecanethiol (C12), were used to modify Ag NPs in two size ranges, 1-3 and 3-6 nm. The organic surface layer successfully suspended the Ag NPs in a poly-alpha-olefin (PAO) base oil with concentrations up to 0.19-0.50 wt %, depending on the particle type. Use of the Ag NPs in the base oil reduced friction by up to 35% and wear by up to 85% in boundary lubrication. The two TBBT-modified NPs produced a lower friction coefficient than the C12-modified one, while the two larger NPs (3-6 nm) had better wear protection than the smaller one (1-3 nm). Results suggested that the molecular structure of the organic ligand might have a dominant effect on the friction behavior, while the NP size could be more influential in the wear protection. No mini-ball-bearing or surface smoothening effects were observed in the Stribeck scans. Instead, the wear protection in boundary lubrication was attributed to the formation of a silver-rich 50-100 nm thick tribofilm on the worn surface, as revealed by morphology examination and composition analysis from both the top surface and cross section.
Bioinspired lubricating films of cellulose nanofibrils and hyaluronic acid.

Science.gov (United States)

Valle-Delgado, Juan José; Johansson, Leena-Sisko; Österberg, Monika

2016-02-01

The development of materials that combine the excellent mechanical strength of cellulose nanofibrils (CNF) with the lubricating properties of hyaluronic acid (HA) is a new, promising approach to cartilage implants not explored so far. A simple, solvent-free method to produce a very lubricating, strong cellulosic material by covalently attaching HA to the surface of CNF films is described in this work. A detailed analysis of the tribological properties of the CNF films with and without HA is also presented. Surface and friction forces at micro/nanoscale between model hard surfaces (glass microspheres) and the CNF thin films were measured using an atomic force microscope and the colloid probe technique. The effect of HA attachment, the pH and the ionic strength of the aqueous medium on the forces was examined. Excellent lubrication was observed for CNF films with HA attached in conditions where the HA layer was highly hydrated. These results pave the way for the development of new nanocellulose-based materials with good lubrication properties that could be used in biomedical applications. Copyright © 2015 Elsevier B.V. All rights reserved.
Nanoscale Organic−Inorganic Hybrid Lubricants

KAUST Repository

Kim, Daniel; Archer, Lynden A.

2011-01-01

Silica (SiO2) nanoparticles densely grafted with amphiphilic organic chains are used to create a family of organic-inorganic hybrid lubricants. Short sulfonate-functionalized alkylaryl chains covalently tethered to the particles form a dense corona
Feasibility study of self-lubrication by chlorine implantation

International Nuclear Information System (INIS)

Akhajdenung, T.; Aizawa, T.; Yoshitake, M.; Mitsuo, A.

2003-01-01

Implantation of chlorine into titanium nitride (TiN) coating on the high-speed steel substrate has succeeded in significant reduction of wear rate and friction coefficient for original TiN under dry wear condition. Through precise investigation on the surface reaction in the wear track, in situ formation of oxygen-deficient titanium oxides was found to play a role as a lubricious oxide. In the present paper, this self-lubrication mechanism is further investigated for various wearing conditions. For wide range of sliding speed and normal load in the wear map, the wear volume of a counter material is actually reduced with comparison to the un-implanted TiN. Effect of the ion implantation dose on this self-lubrication mechanism is also studied for practical use. Some comments are made on further application of this self-lubrication to manufacturing
Treatment of Waste Lubricating Oil by Chemical and Adsorption Process Using Butanol and Kaolin

Science.gov (United States)

Riyanto; Ramadhan, B.; Wiyanti, D.

2018-04-01

Treatment of waste lubricating oil by chemical and adsorption process using butanol and kaolin has been done. Quality of lubricating oil after treatment was analysis using Atomic Absorption Spectrophotometer (AAS) and Gas Chromatography-Mass Spectrometry (GC-MS). The effects of the treatment of butanol, KOH, and kaolin to metals contain in waste lubricating oil treatment have been evaluated. Treatment of waste lubricating oil has been done using various kaolin weight, butanol, and KOH solution. The result of this research show metal content of Ca, Mg, Pb, Fe and Cr in waste lubricating oil before treatment are 1020.49, 367.02, 16.40, 36.76 and 1,80 ppm, respectively. The metal content of Ca, Mg, Pb, Fe and Cr in the waste lubricating oil after treatment are 0.17, 9.85, 34.07, 78.22 and 1.20 ppm, respectively. The optimum condition for treatment of waste lubricating oil using butanol, KOH, and kaolin is 30 mL, 3.0 g and 1.5 g, respectively. Chemical and adsorption method using butanol and kaolin can be used for decrease of metals contain in waste lubricating oil.
Lubricating and waxy esters, I. Synthesis, crystallization, and melt behavior of linear monoesters.

Science.gov (United States)

Bouzidi, Laziz; Li, Shaojun; Di Biase, Steve; Rizvi, Syed Q; Narine, Suresh S

2012-01-01

Four pure jojoba wax-like esters (JLEs), having carbon chain length of 36, 40 (two isomers) and 44, were prepared by Steglish esterification of fatty acids (or acid chlorides) with fatty alcohols at room temperature. Calorimetric and diffraction data was used to elucidate the phase behavior of the esters. The primary thermal parameters (crystallization and melting temperatures) obtained from the DSC of the symmetrical molecules correspond well with the carbon numbers of the JLEs. However, the data also suggests that carbon number is not the only factor since the symmetry of the molecule also plays a significant role in the phase behavior. Overall, the JLEs show very little polymorphic activity at the experimental conditions used, suggesting that they are likely to transform the same way during melting as well as crystallization, a characteristic which may be useful in designing new waxes and lubricants. The XRD data clearly show that the solid phase in all samples consists of a mixture of a β-phase and a β'-phase; fully distinguishable by their characteristic diffraction peaks. Subtle differences between the subcell patterns and phase development of the samples were observed. Different layering of the samples was also observed, understandably because of the chain length differences between the compounds. The long spacings were perfectly linearly proportional to the number of carbon atoms. The length of the ester layers with n carbon atoms can be calculated by a formula similar to that used for the layers in linear alkane molecules. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.
Low Molecular Weight Z-Tetraol Boundary Lubricant Films in Hard Disk Drives

Directory of Open Access Journals (Sweden)

R. J. Waltman

2012-01-01

Full Text Available Lower molecular weight Z-Tetraol films exhibit increased mechanical spacing in the slider-disk interface due to a lower z-profile. An increased resistance to lubricant disturbance on the disk surface (e.g., lube moguls with decreasing film thickness is attributed to an increasing contribution from the polar component of the disjoining pressure. Evaporative loss at temperatures typically encountered in a hard-disk drive also increases with decreasing molecular weight but is strongly dependent on the initial bonded fraction.

Molecular weight evaluation of poly-dimethylsiloxane on solid surfaces using silver deposition/TOF-SIMS

Science.gov (United States)

Inoue, Masae; Murase, Atsushi

2004-06-01

Molecular ions include information about end groups, functional groups and molecular weight. A method for directly detecting this in the high-mass region of the spectrum (>1000 amu) from poly-dimethylsiloxane (PDMS) on a solid surface was investigated. It was found that a TOF-SIMS analysis of silver-deposited surfaces (silver deposition/TOF-SIMS) is useful for this purpose. Two methods for silver deposition, the diode sputtering method and the vacuum evaporation coating method, were tried. The former required the sample to be cooled so as to prevent the damage of the sample surface due to thermal oxidation; the latter caused no damage to sample surfaces at room temperature. Using silver deposition/TOF-SIMS analysis, silver-cationized quasi-molecular ions were clearly detected from PDMS on solid surfaces and their images were observed without the interference of deposited silver. By applying to the analysis of paint defects, etc., it was confirmed that this technique is useful to analyze practical industrial materials. Silver-cationized ions were detected not only from PDMS, but also from other organic materials, such as some kinds of lubricant additives and fluorine oils on solid surfaces. Therefore, silver deposition/TOF-SIMS was proved to be useful for the analysis of thin substances on solid surfaces.
Standard test method for determination of surface lubrication on flexible webs

CERN Document Server

American Society for Testing and Materials. Philadelphia

1999-01-01

1.1 This test method has been used since 1988 as an ANSI/ISO standard test for determination of lubrication on processed photographic films. Its purpose was to determine the presence of process-surviving lubricants on photographic films. It is the purpose of this test method to expand the applicability of this test method to other flexible webs that may need lubrication for suitable performance. This test measures the breakaway (static) coefficient of friction of a metal rider on the web by the inclined plane method. The objectives of the test is to determine if a web surface has a lubricant present or not. It is not intended to assign a friction coefficient to a material. It is not intended to rank lubricants. 1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish ...
Investigation of Lubrication Properties of Petroleum Fuel and Biohydrocarbon Blends

Directory of Open Access Journals (Sweden)

Gawron Bartosz

2016-07-01

Full Text Available The paper covers issues regarding lubricity of petroleum fuels used in piston and turbine engines, containing hydrocarbon biocomponents. Basing on available literature it can be said that the most prospective fuel components are biohydrocarbons. The paper describes effect of biohydrocarbons included in aviation fuel and diesel fuel on lubricity of such blends. The analysis covers two processes for obtaining biohydrocarbons, the HVO and the Fischer-Tropsch process. Due to problems with actual products acquiring, biohydrocarbons models representing chemically the actual ones from specific process. Lubricity testing was carried out according to standard test methods.
Bifurcation of elastic solids with sliding interfaces

Science.gov (United States)

Bigoni, D.; Bordignon, N.; Piccolroaz, A.; Stupkiewicz, S.

2018-01-01

Lubricated sliding contact between soft solids is an interesting topic in biomechanics and for the design of small-scale engineering devices. As a model of this mechanical set-up, two elastic nonlinear solids are considered jointed through a frictionless and bilateral surface, so that continuity of the normal component of the Cauchy traction holds across the surface, but the tangential component is null. Moreover, the displacement can develop only in a way that the bodies in contact do neither detach, nor overlap. Surprisingly, this finite strain problem has not been correctly formulated until now, so this formulation is the objective of the present paper. The incremental equations are shown to be non-trivial and different from previously (and erroneously) employed conditions. In particular, an exclusion condition for bifurcation is derived to show that previous formulations based on frictionless contact or `spring-type' interfacial conditions are not able to predict bifurcations in tension, while experiments-one of which, ad hoc designed, is reported-show that these bifurcations are a reality and become possible when the correct sliding interface model is used. The presented results introduce a methodology for the determination of bifurcations and instabilities occurring during lubricated sliding between soft bodies in contact.
Research of the pre-launch powered lubrication device of major parts of the engine D-240

Science.gov (United States)

Korchuganova, M.; Syrbakov, A.; Tkachev, A.; Zorina, T.

2015-09-01

In the publication, the issues have been considered concerning combustion engine start wear of mobile machines in case of outside storage in the conditions of low environmental temperature. Based on the analysis of existing methods and constructions of powered lubrication devices for contact surfaces of engines, a design of a combined device has been suggested which unites the functions of hydraulic and heat accumulators. On the basis of the elaborated design, preparatory tests have been conducted in order to evaluate the effectiveness of pre-start oil circulation in the engine D-240, as well as the effectiveness rate of thermoinsulation and the heating device of the hydraulic accumulator. The findings of the survey have shown that the pre-start powered lubrication device for major parts of the engine is effective.
Friction and wear performance of low-friction carbon coatings under oil lubrication

International Nuclear Information System (INIS)

Kovalchenko, A.; Ajayi, O. O.; Erdemir, A.; Fenske, G. R.

2001-01-01

Amorphous carbon coatings with very low friction properties were recently developed at Argonne National Laboratory. These coatings have shown good promise in mitigating excessive wear and scuffing problems associated with low-lubricity diesel fuels. To reduce the negative effect of sulfur and other lubricant additives in poisoning the after-treatment catalyst, a lubricant formulation with a low level of sulfur may be needed. Exclusion of proven sulfur-containing extreme pressure (EP) and antiwear additives from oils will require other measures to ensure durability of critical lubricated components. The low-friction carbon coating has the potential for such applications. In the present study, we evaluated the friction and wear attributes of three variations of the coating under a boundary lubrication regime. Tests were conducted with both synthetic and mineral oil lubricants using a ball-on-flat contact configuration in reciprocating sliding. Although the three variations of the coating provided modest reductions in friction coefficient, they all reduced wear substantially compared to an uncoated surface. The degradation mode of oxidative wear on the uncoated surface was replaced by a polishing wear mode on the coated surfaces
Temperature control in a continuously mixed bioreactor for solid-state fermentation

NARCIS (Netherlands)

Nagel, F.J.J.I.; Tramper, J.; Bakker, M.S.N.; Rinzema, A.

2001-01-01

A continuously mixed, aseptic paddle mixer was used successfully for solid-state fermentation (SSF) with Aspergillus oryzae on whole wheat kernels. Continuous mixing improved temperature control and prevented inhomogeneities in the bed. Respiration rates found in this system were comparable to those
Comparison of the tribology performance of nano-diesel soot and graphite particles as lubricant additives

International Nuclear Information System (INIS)

Zhang, Zu-chuan; Cai, Zhen-bing; Peng, Jin-fang; Zhu, Min-hao

2016-01-01

The tribology behavior of exhaust diesel soot as a lubricant additive was investigated and then compared with that of a selection of commercial nano-graphite particles. Specifically, 0.01 wt% particles were dispersed in PAO4 oil with 1 wt% sorbitan monooleate (Span 80) as a dispersing agent, and wear tests based on the ball against plate mode were conducted at various temperatures. Different analytical techniques (e.g. transmission electron, scanning electron and infrared microscopy; energy dispersive x-ray and Raman spectroscopy; and charge measurement) were employed to characterize the chemistry and morphology of the additives and their tribology performance. The oil containing only 0.01 wt% diesel soot clearly improved wear resistance over 60 °C. In particular, at 100 °C the wear rate decreased by approximately 90% compared to the function of base oil. In the same test conditions, diesel soot exhibited better anti-wear performance than nano-graphite at high temperatures. The potential measure showed that the nano-graphite had positive charge and the diesel soot had negative charge. Electrochemical action may play an important role in the lubricant mechanisms of diesel soot and graphite as oil additives. (paper)
Active Lubrication: Feasibility and Limitations on Reducing Vibration in Rotating Machinery

DEFF Research Database (Denmark)

Nicoletti, Rodrigo; Santos, Ilmar

2004-01-01

of increasing their operational range. As a result, one achieves intelligent machines that are more flexible to operate in a fast-changing demand environment. Some limitations of the active lubrication are also discussed based on experimental data, where the response of the servo valves and the supply pressure...... play an important role: the eigenfrequency of the servo valves establishes the operational frequency range of the active lubrication, whereas the supply pressure establishes the amplitude of vibration reduction achieved with the active lubrication....
Hydrophobins as aqueous lubricant additive for a soft sliding contact

DEFF Research Database (Denmark)

Lee, Seunghwan; Røn, Troels; Pakkanen, Kirsi I.

2015-01-01

lubrication characteristic is dominant via ‘self-healing’ mechanism. FpHYD5 revealed a better lubrication than HFBI presumably due to the presence of glycans and improved hydration of the sliding interface. Two type II hydrophobins function more favorably compared to a synthetic amphiphilic copolymer, PEO-PPO...
21 CFR 178.3910 - Surface lubricants used in the manufacture of metallic articles.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Surface lubricants used in the manufacture of... lubricants used in the manufacture of metallic articles. The substances listed in this section may be safely used in surface lubricants employed in the manufacture of metallic articles that contact food, subject...
Men's use and perceptions of commercial lubricants: prevalence and characteristics in a nationally representative sample of American adults.

Science.gov (United States)

Reece, Michael; Herbenick, Debby; Schick, Vanessa; Sanders, Stephanie A; Fortenberry, J Dennis

2014-05-01

Most research on men's use of commercial lubricants during sexual activities is in the context of condom use and often specifically among men who have sex with men. Less is known about men's use of lubricants associated with a broader range of sexual experiences. The aims of this study are to document the prevalence of commercial lubricant use among adult U.S. men (age 18+), to document men's use of lubricants across solo and partnered sexual behaviors, and to assess men's perceptions of the contributions lubricants have to the sexual experience. Data are from the 2012 National Survey of Sexual Health and Behavior, which involved the administration of an online questionnaire to a nationally representative probability sample of U.S. adults ages 18 and older. Sociodemographic characteristics, recent and lifetime commercial lubricant use, lubricant use during specific sexual behaviors, frequency of lubricant use, and reasons for lubricant use. Most men in the United States (70%, N = 1,014) reported having used a commercial lubricant, with men older than 24 and those in a relationship more likely to report lubricant use. About one in four men had used a lubricant in the past 30 days. Intercourse was the most common behavior during which men used lubricant, though solo masturbation and partnered sexual play were also frequently linked to lubricant use. The most common reasons for lubricant use included "to make sex more comfortable," "for fun," "curiosity," and "my partner wanted to." Most American men have used a lubricant; lubricant use is common across all age groups, and some of the most common reasons why men report using lubricants have to do with sexual enhancement, comfort, and pleasure. Clinicians may find these data helpful to their efforts to educate patients about lubricant use, comfort during sex, and sexual enhancement. © 2014 International Society for Sexual Medicine.
IUTAM Symposium on Lubricated Transport of Viscous Materials

CERN Document Server

1998-01-01

The main objective of the First International Symposium on Lubricated Transport of Viscous Materials was to bring together scientists and engineers from academia and industryto discuss current research work and exchange ideas in this newly emerging field. It is an area offluid dynamics devoted to laying bare the principlesofthe lubricated transport of viscous materials such as crude oil, concentrated oil/water emulsion, slurries and capsules. It encompasses several types of problem. Studies of migration of particulates away from walls, Segre-Silverberg effects, lubrication versus lift and shear-induced migration belong to one category. Some of the technological problems are the fluid dynamics ofcore flows emphasizing studies ofstability, problems of start-up, lift-off and eccentric flow where gravity causes the core flow to stratify. Another category of problems deals with the fouling of pipe walls with oil, with undesirable increases in pressure gradients and even blocking. This study involves subjects like ...
Green Lubricants for Metal Forming

DEFF Research Database (Denmark)

Bay, Niels

2010-01-01

The increasing focus on legislation towards diminishing the impact on working environment as well as external environment has driven efforts to develop new, environmentally benign lubricants for metal forming. The present paper gives an overview of these efforts to substitute environmentally...
Microwave assisted sintering of gadolinium doped barium cerate electrolyte for intermediate temperature solid oxide fuel cells

Energy Technology Data Exchange (ETDEWEB)

Kumar, Arumugam Senthil, E-mail: senthu.ramp@gmail.com [Department of Physics, PSG College of Technology, Coimbatore, 641 004, Tamilnadu (India); Balaji, Ramamoorthy [Department of Physics, PSG College of Technology, Coimbatore, 641 004, Tamilnadu (India); Jayakumar, Srinivasalu [Department of Physics, PSG Institute of Technology and Applied Research, Coimbatore, 641 062, Tamilnadu (India); Pradeep, Chandran [Department of Physics, Indian Institute of Technology, Madras, 600 036, Tamilnadu (India)

2016-10-01

In Solid Oxide Fuel Cell (SOFC), electrolyte plays a vital role to increase the energy conversion efficiency. The main hurdle of such electrolyte in fuel cell is its higher operating temperature (1000 °C) which results in design limitation and higher fabrication cost. In order to reduce the operating temperature of SOFC, a suitable electrolyte has been prepared through co-precipitation method followed by microwave sintering of solid ceramic. The calcination temperature for the as-prepared powder was identified using Differential Scanning Calorimetry. The crystal structure of the sample was found to exhibit its orthorhombic perovskite structure. The particle size was determined using High-Resolution Transmission Electron Microscope with uniform in shape and size, match with XRD results and confirmed from structural analysis. Thus, the sample prepared via co-precipitation method and the solid ceramic sintered through microwave can be a promising electrolyte for fuel cells operated at intermediate temperature. - Highlights: • To synthesis the composite electrolyte by chemical method and sinter using microwave. • To reduce the operating temperature of electrolyte for high ionic conductivity in SOFC's. • To study the phase purity and to develop nanocomposite at reduced temperature.
Rolling Friction Torque in Ball-Race Contacts Operating in Mixed Lubrication Conditions

Directory of Open Access Journals (Sweden)

Mihaela Rodica D. Bălan

2015-04-01

Full Text Available Based on a theoretical model and an experimental methodology for defining the friction torque for lubricated conditions in a modified thrust ball bearing having only three balls, the authors experimentally investigated the influence of the lubricant parameter Λ on friction torque for mixed IVR (isoviscous rigid and EHL (elastohydrodynamic lubrication conditions. The experiments were conducted using ball diameters of 3 mm, 3.97 mm and 6.35 mm loaded at 0.125 N, 0.400 N and 0.633 N. Two oils of viscosity 0.08 Pa·s and 0.05 Pa·s were used and rotational speed was varied in the range 60–210 rpm to obtain a lubricant parameter Λ varying between 0.3 and 3.2. The experiments confirmed that the measured friction torque can be explained using hydrodynamic rolling force relationships respecting the transition from an IVR to an EHL lubrication regime.
Controllable Lubrication for Main Engine Bearings Using Mechanical and Piezoelectric Actuators

DEFF Research Database (Denmark)

Estupinan, Edgar; Santos, Ilmar

2012-01-01

Although mechatronic systems are nowadays implemented in a large number of systems in vehicles, active lubrication systems are still incipient in industrial applications. This study is an attempt to extend the active lubrication concept to combustion engines and gives a theoretical contribution...... equations. The global system is numerically solved using as a case study a single-cylinder combustion engine, where the conventional lubrication of the main bearing is modified by applying radial oil injection using piezo-actuated injection. The performance of such a hybrid bearing is compared...
MINIMUM QUANTITY LUBRICANT FLOW ANALYSIS IN END MILLING PROCESSES: A COMPUTATIONAL FLUID DYNAMICS APPROACH

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M. S. Najiha

2012-12-01

Full Text Available This paper presents a two-dimensional steady-state incompressible analysis for the minimum quantity of lubricant flow in milling operations using a computational fluid dynamics (CFD approach. The analysis of flow and heat transfer in a four-teeth milling cutter operation was undertaken. The domain of the rotating cutter along with the spray nozzle is defined. Operating cutting and boundary conditions are taken from the literature. A steady-state, pressure-based, planar analysis was performed with a viscous, realizable k-ε model. A mixture of oils and air were sprayed on the tool, which is considered to be rotating and is at a temperature near the melting temperature of the workpiece. Flow fields are obtained from the study. The vector plot of the flow field shows that the flow is not evenly distributed over the cutter surface, as well as the uneven distribution of the lubricant in the direction of the cutter rotation. It can be seen that the cutting fluid has not completely penetrated the tool edges. The turbulence created by the cutter rotation in the proximity of the tool throws oil drops out of the cutting zone. The nozzle position in relation to the feed direction is very important in order to obtain the optimum effect of the MQL flow.
Materials and lubrication for gear and bearing surfaces in UHV

International Nuclear Information System (INIS)

Kirby, R.E.; Collet, G.J.; Garwin, E.L.

1981-01-01

During design and construction of the SLAC polarized LEED (PLEED) system, a search was made for a dependable gear, bearing and lubrication system for the computer-controlled Faraday cup used to measure diffracted beams. Components must be nonmagnetic, bakeable to 250 0 C, and at room temperature must operate at pressures in the 10 -9 to 10 -10 Pa range. A test system was constructed which incorporated a meshed pair of dissimilar pitch diameter spur gears, one of which was confined by bushings to a fixed shaft on which it rotated, while the other gear was driven through a commercial rotary motion feedthrough rotated by a servo motor driven in sine fashion with a direction reversal every six turns and peak speeds of 50 rpm. The criterion for a successful pair was approx. equal to 10 5 turns, the life rating for the feedthrough. Pairs had actual turn counts from less than 1 to 91 000. Materials for gears included stainless steel, beryllium copper and aluminium alloys. Lubricants used singly and in concert were MoS 2 , WS 2 , Ag, hard chrome and a MoS 2 -graphite-sodium silicate-coated Be-Cu. Subsequent performance in the PLEED system after repeated bakeouts will also be discussed. (orig.)
Effect of the External Lubrication Method for a Rotary Tablet Press on the Adhesion of the Film Coating Layer.

Science.gov (United States)

Kondo, Hisami; Toyota, Hiroyasu; Kamiya, Takayuki; Yamashita, Kazunari; Hakomori, Tadashi; Imoto, Junko; Kimura, Shin-Ichiro; Iwao, Yasunori; Itai, Shigeru

2017-01-01

External lubrication is a useful method which reduces the adhesion of powder to punches and dies by spraying lubricants during the tableting process. However, no information is available on whether the tablets prepared using an external lubrication system can be applicable for a film coating process. In this study, we evaluated the adhesion force of the film coating layer to the surface of tablets prepared using an external lubrication method, compared with those prepared using internal lubrication method. We also evaluated wettability, roughness and lubricant distribution state on the tablet surface before film coating, and investigated the relationship between peeling of the film coating layer and these tablet surface properties. Increasing lubrication through the external lubrication method decreased wettability of the tablet surface. However, no change was observed in the adhesion force of the film coating layer. On the other hand, increasing lubrication through the internal lubrication method, decreased both wettability of the tablet surface and the adhesion force of the film coating layer. The magnesium stearate distribution state on the tablet surface was assessed using an X-ray fluorescent analyzer and lubricant agglomerates were observed in the case of the internal lubrication method. However, the lubricant was uniformly dispersed in the external lubrication samples. These results indicate that the distribution state of the lubricant affects the adhesion force of the film coating layer, and external lubrication maintained sufficient lubricity and adhesion force of the film coating layer with a small amount of lubricant.

Markets for lubricants at a time of upheaval; Schmierstoffmarkt im Umbruch

Energy Technology Data Exchange (ETDEWEB)

Lindemann, Lutz [Fuchs Petrolub AG (Germany)

2011-05-15

The presentation considers the lubricants market and the lubricants under three different points of view. I will discuss the lubricants market under view of the development of the upcoming and existing regulatory risks. The requirements out of the regulations, which need to be fulfilled in the future by the lubricants manufacturer to handle the supply chain in a globalized economy are highlighted. The raw material world will be analyzed, since the raw material becomes a more and more dominating part of the lubricants world. Due to technical requirements the complexity of used raw material becomes a problem in view of the regulatory conditions we are working in. The latest development in the base oil landscape will be discussed. The influence of the changing refinery landscape in Europe and the influence on availability in Europe, USA and Asia are shown. Further more alternative base oils, inorganic additives, i.e. Mo and Li compounds and of course the special chemistry are part of the considerations as well. The third point of view considers the complexity of the lubricant development. The modern lubricant has seen a dramatic change from being a commodity to a process or construction element. The tribology as young discipline in science with a lot of cross-functional aspects requires a lot of additional research to understand more the mechanisms working in the tribosystem. In the farer future this may lead to more predictability than today. The necessity of research in research communities together with universities is mandatory to get the complexity under control. We have to leave the path of phenomenological research to knowledge based development. This is a necessary condition to be faster in development and more effective, which is needed to maintain our European first class position in the globalized world. (orig.)
Progress in Effect of Nano-modified Coatings and Welding Process Parameters on Wear of Contact Tube for Non-copper Coated Solid Wires

Directory of Open Access Journals (Sweden)

LI Zhuo-xin

2017-12-01

Full Text Available Environment-friendly non-copper coated solid wire is the main developing trend for gas shielded solid wires, whereas wear of contact tube limits their wide application. The effect of nano-modified coatings and welding process parameters on wear of contact tube for non-copper coated solid wires was reviewed. It was found that the wear of contact tube can be reduced due to the formation of tribo-films on the rubbing surfaces of welding wires against contact tube; it is feasible to decrease contact tube wear when non-copper coated solid wires are coated with nano-modified lubricants, thereby displaying excellent lubricating and thermal or electrical conduction characteristics. The wear of contact tube increases with the increase of welding current. The wear of contact tube is worse in direct-current electrode positive (DCEP than in direct-current electrode negative (DCEN. Arc ablation and electrical erosion are the dominant wear mechanisms of contact tube.
Modified Ionic Liquid-Based High-Performance Lubricants for Robotic Operations, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — NASA needs an advanced lubrication solution for its future robotic systems and planetary surface assets. The required lubrication technology must offer...
A Novel Bearing Lubricating Device Based on the Piezoelectric Micro-Jet

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Kai Li

2016-02-01

Full Text Available A novel bearing lubricating device, which is embedded in gyroscope’s bearing system and based on the theory of the piezoelectric micro-jet, was designed for this study. The embedded structure of a bearing lubricating system can make effective use of the limited space of bearing systems without increasing the whole mass of the system. The drop-on-demand (DOD lubrication can be realized by the piezoelectric micro-jet system to implement the long acting lubrication of the bearing system. A mathematical model of inlet boundary conditions was established to carry on the numerical simulation based on CFD. The motion states of the droplets with different voltage excitations were analyzed via numerical simulations, and the injection performances of the piezoelectric micro-jet lubricating device were tested in accordance with past experiments. The influences of different parameters of voltage excitation on injection performance were obtained, and the methods of adjusting the injection performance to meet different requirements are given according to the analyses of the results. The mathematical model and numerical simulation method were confirmed by comparing the results of past simulations and experiments.
A newly developed lubricant, chitosan laurate, in the manufacture of acetaminophen tablets.

Science.gov (United States)

Bani-Jaber, Ahmad; Kobayashi, Asuka; Yamada, Kyohei; Haj-Ali, Dana; Uchimoto, Takeaki; Iwao, Yasunori; Noguchi, Shuji; Itai, Shigeru

2015-04-10

To study the usefulness of chitosan laurate (CS-LA), a newly developed chitosan salt, as a lubricant, lubrication properties such as the pressure transmission ratio and ejection force were determined at different concentrations of CS-LA in tableting. In addition, tablet properties such as the tensile strength, disintegration time, and dissolution behavior, were also determined. When CS-LA was mixed at concentrations of 0.1%-3.0%, the pressure transmission ratio was increased in a concentration-dependent manner, and the value at a CS-LA concentration of 3% was equal to that of magnesium stearate (Mg-St), a widely used lubricant. Additionally, a reduction in the ejection force was observed at a concentration from 1%, proving that CS-LA has good lubrication performance. A prolonged disintegration time and decreased tensile strength, which are known disadvantages of Mg-St, were not observed with CS-LA. Furthermore, with CS-LA, retardation of dissolution of the drug from the tablets was not observed. Conjugation of CS with LA was found to be quite important for both lubricant and tablet properties. In conclusion, CS-LA should be useful as an alternative lubricant to Mg-St. Copyright © 2015 Elsevier B.V. All rights reserved.
Study of hydrodynamic behaviour of large bearings depending on the viscosity of the lubricant

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Barabas Sorin

2017-01-01

Full Text Available The research refers to study of hydrodynamic behavior of large bearings equipped with automatic lubrication system, where the liquid used may have a viscosity with variable values depending on the temperature or depending on the additive used. The introduction of additives with nanoparticles causes modification of viscosity and a significant reduction of friction coefficient. This study establishes a direct link between the friction, viscosity and tensions that occur in the contact area. Experimental studies confirm improving tribological properties of the contact area between the bearing rollers and raceways, through attracting nanoparticles on surfaces in contact and reducing friction coefficient. Accomplished finite element analysis showed decrease of the contact stresses, therefore decrease of the wear and increase the life of the bearing. Research has concluded that influencing viscosity and friction coefficient of lubricant can result in reducing wear of the bearing components, as well as increase the lifetime of bearing.
Mathematical Model and Analysis of the Water-Lubricated Hydrostatic Journal Bearings considering the Translational and Tilting Motions

Directory of Open Access Journals (Sweden)

Hui-Hui Feng

2014-01-01

Full Text Available The water-lubricated bearings have been paid attention for their advantages to reduce the power loss and temperature rise and increase load capacity at high speed. To fully study the complete dynamic coefficients of two water-lubricated, hydrostatic journal bearings used to support a rigid rotor, a four-degree-of-freedom model considering the translational and tilting motion is presented. The effects of tilting ratio, rotary speed, and eccentricity ratio on the static and dynamic performances of the bearings are investigated. The bulk turbulent Reynolds equation is adopted. The finite difference method and a linear perturbation method are used to calculate the zeroth- and first-order pressure fields to obtain the static and dynamic coefficients. The results suggest that when the tilting ratio is smaller than 0.4 or the eccentricity ratio is smaller than 0.1, the static and dynamic characteristics are relatively insensitive to the tilting and eccentricity ratios; however, for larger tilting or eccentricity ratios, the tilting and eccentric effects should be fully considered. Meanwhile, the rotary speed significantly affects the performance of the hydrostatic, water-lubricated bearings.
Evaluation of Environmentally Acceptable Lubricants (EALS) for Dams Managed by the U.S. Army Corps of Engineers

Science.gov (United States)

2015-08-01

power, and seal against dirt, dust, and water. Lubricants work by serving as a lower viscosity material between moving surfaces. The wearing surfaces...aluminum, clay , polyurea, sodium, and calcium are most common. Complex thickeners can be composed of metal soaps mixed with low-molecular-weight organic...Polyalkyl DAE N Polyest Rape Seed Viscosity Temperature Behavior (VI) 4 2 2 2 2 2 Low Temperature Behavior (Pourpoint) 5 1 3 1 2 3 Liquid Range 4 2 3 1 2 3
An Advanced Microturbine System with Water-Lubricated Bearings

Directory of Open Access Journals (Sweden)

Susumu Nakano

2009-01-01

Full Text Available A prototype of the next-generation, high-performance microturbine system was developed for laboratory evaluation. Its unique feature is its utilization of water. Water is the lubricant for the bearings in this first reported application of water-lubricated bearings in gas turbines. Bearing losses and limitations under usage conditions were found from component tests done on the bearings and load tests done on the prototype microturbine. The rotor system using the water-lubricated bearings achieved stable rotating conditions at a rated rotational speed of 51,000 rpm. An electrical output of 135 kW with an efficiency of more than 33% was obtained. Water was also utilized to improve electrical output and efficiency through water atomizing inlet air cooling (WAC and a humid air turbine (HAT. The operation test results for the WAC and HAT revealed the WAC and HAT operations had significant effects on both electrical output and electrical efficiency.
The effect of inertia force in water lubricated thrust bearings of canned reactor coolant pump

International Nuclear Information System (INIS)

Deng Liping

1994-01-01

The water lubricated thrust bearings are analyzed. According to characteristic of low viscosity of water the lubricated equation for design and calculation of water lubricated thrust bearings is established. The calculation and analyses show that the effect of inertia force in water lubricated thrust bearings should not be neglected except the conditions of low speed, high angle of inclination and low radius ratio of pad
Vapor-solid-solid growth mechanism driven by an epitaxial match between solid Au Zn alloy catalyst particle and Zn O nano wire at low temperature

International Nuclear Information System (INIS)

Campos, Leonardo C.; Tonezzer, Matteo; Ferlauto, Andre S.; Magalhaes-Paniago, Rogerio; Oliveira, Sergio; Ladeira, Luiz O.; Lacerda, Rodrigo G.

2008-01-01

Nowadays, the growth of nano materials, like nano wires and nano tubes, is one of the key research areas of nano technology. However, a full picture of the growth mechanism of these quasi-one dimensional systems still needs to be achieved if these materials are to be applied electronics, biology and medicinal fields. Nevertheless, in spite of considerable advances on the growth of numerous nano wires, a clear understanding of the growth mechanism is still controversial and highly discussed. The present work provides a comprehensive picture of the precise mechanism of Zn O vapor-solid-solid (VSS) nano wire growth at low temperatures and gives the fundamental reasons responsible. We demonstrate by using a combination of synchrotron XRD and high resolution TEM that the growth dynamics at low temperatures is not governed by the well-known vapor-liquid solid (VLS) mechanisms. A critical new insight on the driving factor of VSS growth is proposed in which the VSS process occurs by a solid diffusion mechanism that is driven by a preferential oxidation process of the Zn inside the alloy catalyst induced by an epitaxial match between the Zn O(10-10) plane and the γ-Au Zn(222) plane. We believe that these results are not only important for the understanding of Zn O nano wire growth but could also have significant impact on the understanding of growth mechanisms of other nano wire systems. (author)
High-temperature x-ray diffraction study of HfTiO4-HfO2 solid solutions

International Nuclear Information System (INIS)

Carpenter, D.A.

1975-01-01

High-temperature x-ray diffraction techniques were used to determine the axial thermal expansion curves of HfTiO 4 -HfO 2 solid solutions as a function of composition. Data show increasing anisotropy with increasing HfO 2 content. An orthorhombic-to-monoclinic phase transformation was detected near room temperature for compositions near the high HfO 2 end of the orthorhombic phase field and for compositions within the two-phase region (HfTiO 4 solid solution plus HfO 2 solid solution). An orthorhombic-to-cubic phase transformation is indicated by data from oxygen-deficient materials at greater than 1873 0 K. (U.S.)
A Review of Tribological Coatings for Control Drive Mechanisms in Space Reactors

International Nuclear Information System (INIS)

CJ Larkin; JD Edington; BJ Close

2006-01-01

Tribological coatings must provide lubrication for moving components of the control drive mechanism for a space reactor and prevent seizing due to friction or diffusion welding to provide highly reliable and precise control of reflector position over the mission lifetime. Several coatings were evaluated based on tribological performance at elevated temperatures and in ultrahigh vacuum environments. Candidates with proven performance in the anticipated environment are limited primarily to disulfide materials. Irradiation data for these coatings is nonexistent. Compatibility issues between coating materials and structural components may require the use of barrier layers between the solid lubricant and structural components to prevent deleterious interactions. It would be advisable to consider possible lubricant interactions prior to down-selection of structural materials. A battery of tests was proposed to provide the necessary data for eventual solid lubricant/coating selection
Experimental verification of nanoparticle jet minimum quantity lubrication effectiveness in grinding

International Nuclear Information System (INIS)

Jia, Dongzhou; Li, Changhe; Zhang, Dongkun; Zhang, Yanbin; Zhang, Xiaowei

2014-01-01

In our experiment, K-P36 precision numerical control surface grinder was used for dry grinding, minimum quantity lubrication (MQL) grinding, nanoparticle jet MQL grinding, and traditional flood grinding of hardened 45 steel. A three-dimensional dynamometer was used to measure grinding force in the experiment. In this research, experiments were conducted to measure and calculate specific tangential grinding force, frictional coefficient, and specific grinding energy, thus verifying the lubrication performance of nanoparticles in surface grinding. Findings present that compared with dry grinding, the specific tangential grinding force of MQL grinding, nanoparticle jet MQL grinding, and flood grinding decreased by 45.88, 62.34, and 69.33 %, respectively. Their frictional coefficient was reduced by 11.22, 29.21, and 32.18 %, and the specific grinding energy declined by 45.89, 62.34, and 69.45 %, respectively. Nanoparticle jet MQL presented ideal lubrication effectiveness, which was attributed to the friction oil film with strong antifriction and anti-wear features formed by nanoparticles on the grinding wheel/workpiece interface. Moreover, lubricating properties of nanoparticles of the same size (50 nm) but different types were verified through experimentation. In our experiment, ZrO 2 nanoparticles, polycrystal diamond (PCD) nanoparticles, and MoS 2 nanoparticles were used in the comparison of nanoparticle jet MQL grinding. The experimental results manifest that MoS 2 nanoparticles exhibited the optimal lubricating effectiveness, followed by PCD nanoparticles. Our research also integrated the properties of different nanoparticles to analyze the lubrication mechanisms of different nanoparticles. The experiment further verified the impact of nanoparticle concentration on the effectiveness of nanoparticle jet MQL in grinding. The experimental results demonstrate that when the nanoparticle mass fraction was 6 %, the minimum specific tangential grinding force
Low temperature synthesis of non-crystaline solids of the system SrO-SiO2

International Nuclear Information System (INIS)

Yamane, M.; Kojima, T.

1981-01-01

Non-crystalline solids within the liquid-liquid immiscibility region in the system SrO-SiO 2 have been prepared from a gel obtained by the hydrolysis of silicon tetramethoxide with an aqueous solution of strontium nitrate. The gel which was porous and translucent at room temperature increased in transparency with heating due to the collapse of micropores until it became completely clear. The gel became opaque again due to the precipitation of α-quartz at higher temperatures. The critical temperatures below which clear solids were obtained fell on a line connecting the glass transition temperatures of vitreous silica and those of SrO-SiO 2 glass prepared by melting. The density and refractive index of the pore-free, clear glassy solid, changed continuously with the SrO content along lines connecting those of vitreous silica and SrO-SiO 2 glasses of high SrO content prepared by melting. The maximum amount of Sr 2+ which could be introduced using an aqueous solution as the starting material corresponded to a composition of 10 SrO x 90 SiO 2 by weight. (orig.)
Carbonization plant for low temperature carbonization of solid fuels

Energy Technology Data Exchange (ETDEWEB)

1948-02-13

A carbonization plant for the low-temperature carbonization of solid fuels, consists of a heat-treating retort including an outer vertical stationary tube, a second inner tube coaxial with the first tube, adapted to rotate round its axis and defining the first tube, and an annular gap where the solid fuel is treated. The inside of the inner tube is divided in two parts, the first fed with superheated steam which is introduced into the annular gap through vents provided in the wall of the inner tube, the second part communicating with the gap by means of vents provided in the wall of the inner tube through which gases and oil vapors evolved from the fuel are evacuated. A combustion furnace is provided in which the hot solid residues evacuated at the bottom of the annular gap are burned and from which hot fumes are evacuated, a conduit surrounding, in the form of a helical flue, outer cylinder of the retort, and in which flow hot fumes; a preliminary drier for the raw solid fuel heated by the whole or a part of the fumes evacuated from the combustion furnace. Means for bringing solid fuels from the outlet of the preliminary drier to the upper inlet of the gap of the retort a pipe line receiving steam and bringing it into the first inside part of the inner tube, this pipe line has portions located within the conduit for the fumes in order to superheat the steam, and an expansion chamber in which the gases and oil vapors are trapped at the bottom of the second inside part of the inner tube are included.
Rheology Guided Rational Selection of Processing Temperature To Prepare Copovidone-Nifedipine Amorphous Solid Dispersions via Hot Melt Extrusion (HME).

Science.gov (United States)

Yang, Fengyuan; Su, Yongchao; Zhang, Jingtao; DiNunzio, James; Leone, Anthony; Huang, Chengbin; Brown, Chad D

2016-10-03

The production of amorphous solid dispersions via hot melt extrusion (HME) relies on elevated temperature and prolonged residence time, which can result in potential degradation and decomposition of thermally sensitive components. Herein, the rheological properties of a physical mixture of polymer and an active pharmaceutical ingredient (API) were utilized to guide the selection of appropriate HME processing temperature. In the currently studied copovidone-nifedipine system, a critical temperature, which is substantially lower (∼13 °C) than the melting point of crystalline API, was captured during a temperature ramp examination and regarded as the critical point at which the API could molecularly dissolve into the polymer. Based on the identification of this critical point, various solid dispersions were prepared by HME processing below, at, and above the critical temperature (both below and above the melting temperature (T m ) of crystalline API). In addition, the resultant extrudates along with two control solid dispersions prepared by physical mixing and cryogenic milling were assessed by X-ray diffraction, differential scanning calorimetry, hot stage microscopy, rheology, and solid-state NMR. Physicochemical properties of resultant solid dispersions indicated that the identified critical temperature is sufficient for the polymer-API system to reach a molecular-level mixing, manifested by the transparent and smooth appearance of extrudates, the absence of API crystalline diffraction and melting peaks, dramatically decreased rheological properties, and significantly improved polymer-API miscibility. Once the critical temperature has been achieved, further raising the processing temperature only results in limited improvement of API dispersion, reflected by slightly reduced storage modulus and complex viscosity and limited improvement in miscibility.
A low temperature cryostat with a refrigerator for studying electron-irradiation effects on solids, 2

International Nuclear Information System (INIS)

Oka, Takashi; Yoshida, Toshio; Shono, Yoshihiko

1978-01-01

A convenient cryostat with a small cryogenic refrigerator for studying electron-irradiation effects on solids is reported. The lowest temperature at the sample room is about 10 K or less. In a temperature region below 80 K, the sample temperature can be controlled within 0.05 K. (auth.)
Normal Contacts of Lubricated Fractal Rough Surfaces at the Atomic Scale

NARCIS (Netherlands)

Solhjoo, Soheil; Vakis, Antonis I.

The friction of contacting interfaces is a function of surface roughness and applied normal load. Under boundary lubrication, this frictional behavior changes as a function of lubricant wettability, viscosity, and density, by practically decreasing the possibility of dry contact. Many studies on
Effectiveness of Biodiesel from Various Tropical Oil Crops on Lubricity Improvement of Ultra Low Sulfur Diesel (ULSD)

Energy Technology Data Exchange (ETDEWEB)

Chollacoop, Nuwong; Topaiboul, Subongkoj; Goodwin, Vituruch (Bioenergy Group, National Metal and Materials Technology Center (MTEC), Thailand Science Park, Pathumthani, 12120 (Thailand)). e-mail: nuwongc@mtec.or.th

2008-10-15

Ultra low sulfur diesel (ULSD) has been introduced worldwide with an aim to reduce emission. Since the desulfurization process for ULSD inadvertently reduces its lubricity, lubricity additive is needed. Biodiesel emerges as a potential candidate due to its excellent lubricity property and little sulfur content. In the present study, biodiesel from various energy crops available in Thailand was added at various amounts to ULSD to test the lubricity according to the CEC-F-06-A-96 standard (using High-Frequency Reciprocating Rig: HFRR [1]). It was found that when biodiesel from crude palm, jatropha, soybean, coconut, sunflower, rice, corn and sesame oils of less than 1% (by volume) is additized to ULSD, the lubricity is improved to meet the diesel standard. Further addition beyond 2% (by volume) does not improve lubricity remarkably, where the lubrication seems to saturate. Biodiesel improves lubricity property by film formation preventing mechanical contact between the rubbing surfaces, and the effectiveness varies among different feedstock oils. Biodiesel from crude palm oil, jatropha oil and coconut oil seemingly are superior lubricity additives in ULSD than that from soybean oil, sunflower oil, rice oil, corn oil and sesame oil. Keywords: biodiesel, bio-lubricants, palm oil, sunflower oil

Characterization of used lubricating oil by spectrometric techniques

Energy Technology Data Exchange (ETDEWEB)

Souza, Andressa Moreira de, E-mail: andressa@ctaa.embrapa.br [Embrapa Agroindustria de Alimentos, Guaratiba, Rio de Janeiro, RJ (Brazil); Correa, Sergio Machado [Faculdade de Engenharia. Universidade do Estado do Rio de Janeiro (UERJ), Resende, RJ (Brazil); Silva, Glauco Correa da [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

2011-07-01

Full text: The engine lubricating oil drags all kinds of impurities generated by wear of internal components. Thus, it is necessary to monitor the physical and chemical properties and concentration of metals in lubricants used to determine the appropriate time to replace them. Moreover, one can monitor the wear of the engines through the levels of metals in oils. To achieve these goals, some detection techniques such as Flame atomic absorption spectrometry (FAAS), Inductively coupled plasma optical emission spectrometry (ICP-OES) and X-ray fluorescence (XRF), have been widely used to determine metals in lubricating oils and also in other oil derivatives. Thus, some of these techniques were used in this study. Also the technique used was Gas chromatography mass spectrometry (GC / MS) for characterization of chromatographic profile of the engine lubricating oil after use. Through the technique of ICP-OES for method of United States Environmental Protection Agency (USEPA) METHOD 6010B - Inductively coupled plasma optical emission spectrometry was performed to characterize metals in lubricating oil motor, using equipment from ICP-OES Perkin-Elmer{sup R} OPTIMA 3000 ICP-Winlab and software, obtaining the following identification of metals: barium (Ba), calcium (Ca), lead (Pb), copper (Cu), Chromium (Cr), iron (Fe), magnesium (Mg), molybdenum (Mo) and zinc (Zn). Using the XRF technique, through the equipment EDFRX Shimadzu{sup R} model 800HS EDX, Rh tube, applied voltage of 50kV, amperage 100{mu}A, detector Si (Li) cooled with liquid nitrogen and collimator 10mm, we analyzed all the components comprised in the range of Ti to U and Na to SC, identified the following metals: calcium (Ca), zinc (Zn), iron (Fe), copper (Cu), molybdenum (Mo) and nickel (Ni). The characterization was performed by chromatographic methods: USEPA METHOD 5021A - Volatile organic compounds in various sample matrices using equilibrium headspace analysis, USEPA METHOD 8015B - Nonhalogenated Organics
Characterization of used lubricating oil by spectrometric techniques

International Nuclear Information System (INIS)

Souza, Andressa Moreira de; Correa, Sergio Machado; Silva, Glauco Correa da

2011-01-01

Full text: The engine lubricating oil drags all kinds of impurities generated by wear of internal components. Thus, it is necessary to monitor the physical and chemical properties and concentration of metals in lubricants used to determine the appropriate time to replace them. Moreover, one can monitor the wear of the engines through the levels of metals in oils. To achieve these goals, some detection techniques such as Flame atomic absorption spectrometry (FAAS), Inductively coupled plasma optical emission spectrometry (ICP-OES) and X-ray fluorescence (XRF), have been widely used to determine metals in lubricating oils and also in other oil derivatives. Thus, some of these techniques were used in this study. Also the technique used was Gas chromatography mass spectrometry (GC / MS) for characterization of chromatographic profile of the engine lubricating oil after use. Through the technique of ICP-OES for method of United States Environmental Protection Agency (USEPA) METHOD 6010B - Inductively coupled plasma optical emission spectrometry was performed to characterize metals in lubricating oil motor, using equipment from ICP-OES Perkin-Elmer R OPTIMA 3000 ICP-Winlab and software, obtaining the following identification of metals: barium (Ba), calcium (Ca), lead (Pb), copper (Cu), Chromium (Cr), iron (Fe), magnesium (Mg), molybdenum (Mo) and zinc (Zn). Using the XRF technique, through the equipment EDFRX Shimadzu R model 800HS EDX, Rh tube, applied voltage of 50kV, amperage 100μA, detector Si (Li) cooled with liquid nitrogen and collimator 10mm, we analyzed all the components comprised in the range of Ti to U and Na to SC, identified the following metals: calcium (Ca), zinc (Zn), iron (Fe), copper (Cu), molybdenum (Mo) and nickel (Ni). The characterization was performed by chromatographic methods: USEPA METHOD 5021A - Volatile organic compounds in various sample matrices using equilibrium headspace analysis, USEPA METHOD 8015B - Nonhalogenated Organics Using GC
Experimental Measurements of Journal Bearing Friction Using Mineral, Synthetic, and Bio-Based Lubricants

Directory of Open Access Journals (Sweden)

Pantelis G. Nikolakopoulos

2015-04-01

Full Text Available The environmental impact of many industrial and naval applications is becoming increasingly important. Journal bearings are crucial components related with the reliable, safe and environmentally friendly operation of rotating machinery in many applications, e.g., in hydroplants, ships, power generation stations. The maintenance activities in certain cases also have considerable environmental impact. Fortunately, it is relatively easy to reduce the impact by changing the way lubricants are being used. Selecting the proper lubricant is important to sharply reduce long-term costs. The best-fit product selection can mean longer lubricant life, reduced machine wear, reduced incipient power losses and improved safety. Suitable basestocks and additives reduce environmental impact. In this paper, three types of lubricants are used in order to examine their effects on the tribological behavior of journal bearings. A mineral oil, a synthetic oil and a bio-based lubricant are experimentally and analytically examined for several configurations of load and journal rotational velocity. The friction forces and the hydrodynamic friction coefficients are calculated and compared. This investigation can assist the correct choice of lubricant in journal bearings with minimized environmental footprint.
Analysis of BJ493 diesel engine lubrication system properties

Science.gov (United States)

Liu, F.

2017-12-01

The BJ493ZLQ4A diesel engine design is based on the primary model of BJ493ZLQ3, of which exhaust level is upgraded to the National GB5 standard due to the improved design of combustion and injection systems. Given the above changes in the diesel lubrication system, its improved properties are analyzed in this paper. According to the structures, technical parameters and indices of the lubrication system, the lubrication system model of BJ493ZLQ4A diesel engine was constructed using the Flowmaster flow simulation software. The properties of the diesel engine lubrication system, such as the oil flow rate and pressure at different rotational speeds were analyzed for the schemes involving large- and small-scale oil filters. The calculated values of the main oil channel pressure are in good agreement with the experimental results, which verifies the proposed model feasibility. The calculation results show that the main oil channel pressure and maximum oil flow rate values for the large-scale oil filter scheme satisfy the design requirements, while the small-scale scheme yields too low main oil channel’s pressure and too high. Therefore, application of small-scale oil filters is hazardous, and the large-scale scheme is recommended.
Self-lubricating layer consist of polytetrafluoroethylene micropowders and fluorocarbon acrylate resin formation on surface of geotextile

Science.gov (United States)

Long, Xiaoyun; He, Lifen; Zhang, Yan; Ge, Mingqiao

2018-04-01

In this study, the self-lubricating layer consist of polytetrafluoroethylene (PTFE) micropowders and two types fluorocarbon acrylate resin were formed on the surface of geotextile, to improves the evenness and decreases the frictional angle value of geotextile surface. The surface and cross section morphology of geotextile were examined by scanning electron microscopy (SEM). It was determined that composite resin emulsion was evenly coated on the surface of geotextile, to form a even and complete self-lubricating layer, and it was strongly combined with the geotextile due to formation of the transition layer. The tensile fracture stress and strain values of samples were evaluated by mechanical properties measurement, the tensile fracture stress of the untreated and treated sample was approximately 5329 kN/m and 5452 kN/m while the elongation at the yield of them was approximately 85% to 83.9%, respectively. In addition, the frictional angle values of municipal solid waste (MSW)/geotextile interface was measured by the tilt table test, the values of untreated sample was 28.1° and 24.2° under the dry and moist condition, the values of treated sample was 16.2° and 9.8°, respectively.
Controllable sliding bearings and controllable lubrication principles-an overview

DEFF Research Database (Denmark)

Santos, Ilmar F.

2018-01-01

-mechanical actuators have been coupled to such bearings. Depending on (i) the actuator type; (ii) the actuation principle, i.e., hydraulic, pneumatic, piezoelectric or magnetic among others; and (iii) how such an actuator is coupled to the sliding bearings, different regulation and control actions of fluid film...... bearing gap and its preload via moveable and compliant sliding surfaces; and (d) the control of the lubricant viscosity. All four parameters, i.e., pressure, flow (velocity profiles), gap and viscosity, are explicit parameters in the modified form of Reynolds' equations for active lubrication....... In this framework, this paper gives one main original contribution to the state-of-the-art of radial sliding bearings and controllable lubrication: a comprehensive overview about the different types of controllable sliding bearings and principles used by several authors. The paper ends with some conclusive remarks...
Fluorescence excitation-emission matrix spectroscopy for degradation monitoring of machinery lubricants

Science.gov (United States)

Sosnovski, Oleg; Suresh, Pooja; Dudelzak, Alexander E.; Green, Benjamin

2018-02-01

Lubrication oil is a vital component of heavy rotating machinery defining the machine's health, operational safety and effectiveness. Recently, the focus has been on developing sensors that provide real-time/online monitoring of oil condition/lubricity. Industrial practices and standards for assessing oil condition involve various analytical methods. Most these techniques are unsuitable for online applications. The paper presents the results of studying degradation of antioxidant additives in machinery lubricants using Fluorescence Excitation-Emission Matrix (EEM) Spectroscopy and Machine Learning techniques. EEM Spectroscopy is capable of rapid and even standoff sensing; it is potentially applicable to real-time online monitoring.
Effect of solid lubricants on friction and wear behaviour of alloyed ...

Indian Academy of Sciences (India)

ponents which would physically or chemically absorb on the surface to prevent ... performance of commercially available titanium dioxide with other lamellar solids. ..... TIMCAL Ltd. 2004 Test report on graphite and carbon, Bodio, Switzerland.
Integrated Mechanical Pulse Jet Coolant Delivery System Performance for Minimal Quantity Lubrication

OpenAIRE

Nik Fazli Sapian; Badrul Omar; Mohd Hamdi Abd Shukor

2010-01-01

Minimum quantity lubrication (MQL) machining is one of the promising solutions to the requirement for decrease in cutting fluid consumption. This research describes MQL machining in a range of lubricant consumption 2.0ml/h, which is 10–100 times smaller than the consumption usually adopted in industries. MQL machining in this range is called pulse jet coolant delivery system in this research. A specially designed system was used for concentrating small amounts of lubricant onto the cutting in...
Tribological characteristics of monodispersed cerium borate nanospheres in biodegradable rapeseed oil lubricant

Energy Technology Data Exchange (ETDEWEB)

Boshui, Chen, E-mail: boshuichen@163.com; Kecheng, Gu; Jianhua, Fang; Jiang, Wu; Jiu, Wang; Nan, Zhang

2015-10-30

Graphical abstract: - Highlights: • Monodispersed stearic acid-capped cerium borate composite nanoparticles were prepared by hydrothermal method. Their morphologies, element compositions, size distributions, crystal and chemical structures, hydrophobic characteristics were also characterized. • The surface-capped cerium borate nanoparticles exhibited excellent dispersing stability in rapeseed oil. As new lubricating additives, they were also outstanding in enhancing friction-reducing and anti-wear capacities of rapeseed oil in biodegradable rapeseed oil. The results presented in this paper would be of important significance for developing green lubricants and lubricant additives. • The prominent tribological performances of SA/CeBO{sub 3} in rapeseed oil were investigated and attributed to the formation of a composite boundary lubrication film mainly composed of lubricous tribochemical species on the tribo-surfaces. - Abstract: Stearic acid-capped cerium borate composite nanoparticles, abbreviated as SA/CeBO{sub 3}, were prepared by hydrothermal method. The morphologies, element compositions, size distributions, crystal and chemical structures, hydrophobic characteristics, of SA/CeBO{sub 3} were characterized by scanning electron microscope, energy dispersive X-ray spectrometer, dynamic laser particle size analyzer, X-ray diffraction, and Fourier transform infrared spectrometer, respectively. The friction and wear performances of SA/CeBO{sub 3} as a lubricating additive in a rapeseed oil were evaluated on a four-ball tribo-tester. The tribochemical characteristics of the worn surfaces were investigated by X-ray photoelectron spectroscopy. The results showed that the hydrophobic SA/CeBO{sub 3} were monodispersed nanospheres with an average diameter of 8 nm, and exhibited excellent dispersing stability in rapeseed oil. Meanwhile, SA/CeBO{sub 3} nanospheres were outstanding in enhancing friction-reducing and anti-wear capacities of rapeseed oil. The prominent
Testing of Lubricant Performance in Sheet Metal Forming

DEFF Research Database (Denmark)

Bay, Niels; Olsson, David Dam; Friis, Kasper Leth

2008-01-01

Increasing focus on environmental issues in industrial production has urged a number of sheet metal forming companies to look for new tribo-systems in order to substitute hazardous lubricants such as chlorinated paraffin oils. The problems are especially pronounced, when forming tribologically...... of the lubricant film causing pick-up of work piece material on the tool surface and scoring of subsequent work piece surfaces. The present paper gives an overview of more than 10 years work by the authors’ research group through participation in national as well as international framework programmes on developing...
Application of strip-reduction-test in hte evaluation of lubricants developed in Enform project

DEFF Research Database (Denmark)

Andreasen, Jan Lasson; Olsson, David Dam; Gazvoda, S.

2001-01-01

The performance of three different lubricants in relation to sheet metal forming of steel, Zinc coated steel and stainless steel is investigated in the present paper. A strip reduction test simulating can wall ironing is used. The test was originally developed for determining the limits...... of lubrication in forming of stainless steel by quantification of the degree of galling. The present results show that the test methodology to some extend can be used in testing of lubricants for Zinc coated steels whereas the lubricant performance in forming of steel is more complicated to quantify since...
INVESTIGATING OF ECO- AND ENERGY-EFFICIENT LUBRICATION STRATEGIES FOR THE DRILLING OF LIGHT METAL ALLOYS

Directory of Open Access Journals (Sweden)

N.F. Treurnicht

2012-01-01

Full Text Available
ENGLISH ABSTRACT: Energy use will be one of the main drivers for the achievement of more eco-efficient drilling processes in the automotive industry. Industry awareness of the environmental impact of used cutting emulsions, and the negative effect on worker health, has increased sharply. This has led to innovative lubrication methods such as through-spindle minimal quantity lubrication (MQL for drilling aluminium-silicon alloys. In this work the performance of MQL at different cutting speeds and feed rates has been investigated using infrared temperature measurements. The results indicate that MQL is a feasible eco-efficient alternative to conventional flood cooling when drilling aluminium-silicon alloys.
AFRIKAANSE OPSOMMING: Energiebenutting maak een van die hoofdryfvere uit om eko-doeltreffendheid te behaal in boorprosesse in die motornywerheid. Nywerheidsbewustheid van die omgewingsimpak van gebruikte sny-vloeistowwe, en die negatiewe effek daarvan op werkergesondheid, het skerp toegeneem. Hierdie bewustheid het aanleiding gegee tot die ontwikkeling van smeringsmetodes soos deur-spil minimale hoeveelheid smering (Engels: Minimal Quantity Lubrication, MQL vir die boor van aluminium-silikon legerings. In hierdie werk word die prestasie van MQL ondersoek teen verskillende snyspoed- en voertempo-kondisies deur middel van infra-rooi temperatuurmeting. Die resultate dui daarop dat MQL ’n lewensvatbare eko-vriendelike alternatief tot konvensionele vloedverkoeling is, wanneer aluminium-silikon legerings geboor word.
Comparison of in vivo efficacy of different ocular lubricants in dry eye animal models.

Science.gov (United States)

Zheng, Xiaodong; Goto, Tomoko; Ohashi, Yuichi

2014-04-29

To compare the efficacy of three types of ocular lubricants in protecting corneal epithelial cells in dry eye animal models. Ocular lubricants containing 0.1% or 0.3% sodium hyaluronate (SH), carboxymethylcellulose (CMC), or hydroxypropyl methylcellulose (HPMC) were tested. First, ocular lubricant containing 0.002% fluorescein was dropped onto the rabbit corneas. The fluorescein intensity as an index of retention was measured. Second, a rabbit dry eye model was made by holding the eye open with a speculum, and 50 μL of each ocular lubricant was dropped onto the cornea. After 3 hours, the corneas were stained with 1% methylene blue (MB), and the absorbance of MB was measured. Third, a rat dry eye model was treated with the ocular lubricants for 4 weeks, and the corneal fluorescein staining was scored. Eyes treated with physiological saline were used as controls. Finally, immunohistochemistry was used to analyze occludin, an epithelial barrier protein, in cultured human corneal epithelial cells pretreated with ocular lubricants and desiccated for 20 or 60 minutes. Our results showed that 0.3% SH had a significantly longer retention time than the other lubricants (all P eye syndrome. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.
Effects of disintegration-promoting agent, lubricants and moisture treatment on optimized fast disintegrating tablets.

Science.gov (United States)

Late, Sameer G; Yu, Yi-Ying; Banga, Ajay K

2009-01-05

Effects of calcium silicate (disintegration-promoting agent) and various lubricants on an optimized beta-cyclodextrin-based fast-disintegrating tablet formulation were investigated. Effects of moisture treatment were also evaluated at 75, 85 and 95% relative humidities. A two factor, three levels (3(2)) full factorial design was used to optimize concentrations of calcium silicate and lubricant. Magnesium stearate, being commonly used lubricant, was used to optimize lubricant concentration in optimization study. Other lubricants were evaluated at an obtained optimum concentration. Desiccator with saturated salt solutions was used to analyze effects of moisture treatments. Results of multiple linear regression analysis revealed that concentration of calcium silicate had no effect; however concentration of lubricant was found to be important for tablet disintegration and hardness. An optimized value of 1.5% of magnesium stearate gave disintegration time of 23.4 s and hardness of 1.42 kg. At an optimized concentration, glycerol dibehenate and L-leucine significantly affected disintegration time, while talc and stearic acid had no significant effect. Tablet hardness was significantly affected with L-leucine, while other lubricants had no significant effect. Hardness was not affected at 75% moisture treatment. Moisture treatment at 85 and 95% increased hardness of the tablets; however at the same time it negatively affected the disintegration time.
Time-resolved imaging of a compressible air disc under a drop impacting on a solid surface

KAUST Repository

Li, Erqiang; Thoroddsen, Sigurdur T

2015-01-01

When a drop impacts on a solid surface, its rapid deceleration is cushioned by a thin layer of air, which leads to the entrapment of a bubble under its centre. For large impact velocities the lubrication pressure in this air layer becomes large
NATO Advanced Research Workshop on Boron Rich Solids Sensors for Biological and Chemical Detection, Ultra High Temperature Ceramics, Thermoelectrics, Armor

CERN Document Server

Orlovskaya, Nina

2011-01-01

The objective of this book is to discuss the current status of research and development of boron-rich solids as sensors, ultra-high temperature ceramics, thermoelectrics, and armor. Novel biological and chemical sensors made of stiff and light-weight boron-rich solids are very exciting and efficient for applications in medical diagnoses, environmental surveillance and the detection of pathogen and biological/chemical terrorism agents. Ultra-high temperature ceramic composites exhibit excellent oxidation and corrosion resistance for hypersonic vehicle applications. Boron-rich solids are also promising candidates for high-temperature thermoelectric conversion. Armor is another very important application of boron-rich solids, since most of them exhibit very high hardness, which makes them perfect candidates with high resistance to ballistic impact. The following topical areas are presented: •boron-rich solids: science and technology; •synthesis and sintering strategies of boron rich solids; •microcantileve...
Tribological Behaviour of W-DLC against an Aluminium Alloy Subjected to Lubricated Sliding

Directory of Open Access Journals (Sweden)

S. Bhowmick

2015-09-01

Full Text Available Diamond like carbon (DLC coatings mitigate aluminium adhesion and reduce friction under the ambient conditions but their tribological behaviour under lubricated sliding need to be further investigated. In this study, tribological tests were performed to evaluate the friction and wear characteristics of W-DLC and H-DLC coatings sliding against an aluminium alloy (319 Al under unlubricated (40 % RH and lubricated sliding conditions. For unlubricated sliding, coefficient of friction (COF values of H-DLC and W-DLC were 0.15 and 0.20. A lower COF value of 0.11 was observed when W-DLC was tested using lubricant oil incorporating sulphur while the H-DLC’s COF remained almost unchanged. The mechanisms responsible for the low friction of W-DLC observed during lubricated sliding were revealed by studying the compositions of the coating surfaces and the transfer layers formed on 319 Al. Micro-Raman spectroscopy indicated that the transfer layers formed during lubricated sliding of W-DLC incorporated tungsten disulphide (WS2.
Development of high performance lubricant through the compatibilization of polyalphaolefin, polyurea and irradiated polytetrafluoroethylene

International Nuclear Information System (INIS)

Ratao, Natalia T.; Zen, Heloisa A.; Lugao, Ademar B.

2013-01-01

High performance lubricants are essential for shipping and oil exploration industries for working under severe conditions of temperature, pressure and contamination. Polytetrafluoroethylene (PTFE) is widely used as a lubricating additive in greases for presenting the lowest known coefficient of friction, is commercially found irradiated in air, by this way can be grinded and oxygenated terminal groups can be formed. PTFE processed by ionizing radiation with 4μ average particle size was supplied by Uniflon and compared with the ultraviolet-irradiated PTFE with the same average particle size, from Dupont. The characterization of functional proprieties by drop point, oil separation and four ball test was conducted with a polyurea base grease additive with both types of PTFE. The chemical characterization was done with Differential Scanning Calorimetry (DSC). The drop point and oil separation tests showed that the Uniflon irradiated PTFE improved the thermal resistance and stability of polyurea grease due to the greater presence of the end groups increase the compatibility of the additive with the fluid. Four ball tests showed that the grease with Uniflon irradiated PTFE also has a better antiwear and extreme pressure performance because of the greater polarity of the molecules improving the dispersion and anchoring of the PTFE in metal surface voids, reducing wear. The PTFE processed by ionizing radiation showed greater compatibility with polyurea grease and polyalphaolefin fluid and the grease functional characteristics met the requirements for a high performance lubricant. (author)
The Effects of Acid Passivation, Tricresyl Phosphate Presoak, and UV/Ozone Treatment on the Tribology of Perfluoropolyether-Lubricated 440C Stainless Steel Couples

Science.gov (United States)

Shogrin, Bradley A.; Jones, William R., Jr.; Herrera-Fierro, Pilar; Jansen, Mark J.

2001-01-01

The boundary-lubrication performance of two perfluoropolyether (PFPE) thin films in the presence of passivated 440C stainless steel is presented. The study used a standard ball on disk (BoD) tribometer in dry nitrogen and a vacuum spiral orbit tribometer (SOT). Stainless steel surfaces were passivated with one of four techniques: high and low temperature chromic acid bath, a tricresyl phosphate (TCP) soak, or UV/Ozone treated for 15 min. After passivation, each BoD disk had a 400A film of Krytox 16256 (PFPE) applied to it. The lifetimes of these films were quantified by measuring the number of sliding cycles before an increase in friction occurred. The lubricated lifetime of the 440C couple was not altered as a result of the various passivation techniques. The resulting surface chemistry of each passivation technique was examined using X-ray photoelectron spectroscopy (XPS). The SOT was used to examine the effects of the TCP treatment on the lubricated lifetime of another PFPE, Brayco 815Z, under rolling conditions. None of the passivation techniques were found to dramatically increase the oxide film thickness or lubricated lifetimes.

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