WorldWideScience

Sample records for solid lubricating coatings

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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...

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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...

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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

  4. Preparation and Properties of Microarc Oxidation Self-Lubricating Composite Coatings on Aluminum Alloy

    Directory of Open Access Journals (Sweden)

    Zhenwei Li

    2017-04-01

    Full Text Available Microarc oxidation (MAO coatings were prepared on 2024-T4 aluminum alloy using pulsed bipolar power supply at different cathode current densities. The MAO ceramic coatings contained many crater-like micropores and a small number of microcracks. After the MAO coatings were formed, the coated samples were immersed into a water-based Polytetrafluoroethylene (PTFE dispersion. The micropores and microcracks on the surface of the MAO coatings were filled with PTFE dispersion for preparing MAO self-lubricating composite coatings. The microstructure and properties of MAO coatings and the wear resistance of microarc oxidation self-lubricating composite coatings were analyzed by SEM, laser confocal microscope, X-ray diffractometry (XRD, Vickers hardness test, scratch test and ball-on-disc abrasive tests, respectively. The results revealed that the wear rates of the MAO coatings decreased significantly with an increase in cathode current density. Compared to the MAO coatings, the microarc oxidation self-lubricating composite coatings exhibited a lower friction coefficient and lower wear rates.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Preparation of flame sprayed poly(tetrafluoroethylene-co-hexafluoropropylene) coatings and their tribological properties under water lubrication

    International Nuclear Information System (INIS)

    Feng Zhizhong; Xu Haiyan; Yan Fengyuan

    2008-01-01

    Poly(tetrafluoroethylene-co-hexafluoropropylene) (FEP) coatings were prepared on AISI-1045 steel via flame spraying. The chemical changes of the FEP powder occurring during the spraying process were analyzed by means of Fourier transformation infrared spectroscopy. The flame spraying of the FEP powders under the chosen conditions did not lead to structural changes related to degradation and oxidation. The friction and wear behaviors of the FEP coatings sliding against AISI-52100 steel ball under dry- and water-lubricated conditions were investigated using a ball-on-disc test rig, and the worn surface morphologies of the coatings were also observed using the scanning electron microscope. The FEP coatings recorded smaller friction coefficients under water lubrication than under dry sliding. However, the wear rate of the coating under water lubrication was about two times of that under dry sliding. This indicated that water as a lubricant was able to effectively reduce the friction coefficient but it led to an increased wear rate of the FEP coatings/steel sliding pairs. X-ray photoelectron spectroscope (XPS) results illustrate that the transfer film did formed during the dry sliding but it is hindered under water lubrication, and it might be the major cause of the larger wear rate under the water lubrication.

  12. 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.

  13. Synthetic lubrication oil influences on performance and emission characteristic of coated diesel engine fuelled by biodiesel blends

    International Nuclear Information System (INIS)

    Mohamed Musthafa, M.

    2016-01-01

    Highlights: • Synthetic lubricant provides the maximum performance benefits. • Synthetic lubricant is capable of retaining satisfactory viscosity. • Synthetic lubricant is to increase the life of the engine. • Improvement in efficiency of the coated engine with synthetic lubrication. • No significant changes in the coated engine emission with synthetic lubricants. - Abstract: In this study, the effects of using synthetic lubricating oil on the performance and exhaust emissions in a low heat rejection diesel engine running on Pongamia methyl ester blends and diesel have been investigated experimentally compared to those obtained from a conventional diesel engine with SAE 40 lubrication oil fuelled by diesel. For this purpose, direct injection diesel engine was converted to Yttria-stabilized zirconia (YSZ) coated engine. The results showed 5–9% increase in engine efficiency and 8–17% decrease in specific fuel consumption, as well as significant improvements in exhaust gas emissions (except NO_X) for all tested fuels (pure diesel, B10 and B20) used in coated engine with synthetic lubricants compared to that of the uncoated engine with SAE 40 lubricant running on diesel fuel.

  14. 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.

  15. Phospholipid-Coated Mesoporous Silica Nanoparticles Acting as Lubricating Drug Nanocarriers

    Directory of Open Access Journals (Sweden)

    Tao Sun

    2018-05-01

    Full Text Available Osteoarthritis (OA is a severe disease caused by wear and inflammation of joints. In this study, phospholipid-coated mesoporous silica nanoparticles (MSNs@lip were prepared in order to treat OA at an early stage. The phospholipid layer has excellent lubrication capability in aqueous media due to the hydration lubrication mechanism, while mesoporous silica nanoparticles (MSNs act as effective drug nanocarriers. The MSNs@lip were characterized by scanning electron microscope, transmission electron microscope, Fourier transform infrared spectrum, X-ray photoelectron spectrum, thermogravimetric analysis and dynamic light scattering techniques to confirm that the phospholipid layer was coated onto the surface of MSNs successfully. A series of tribological tests were performed under different experimental conditions, and the results showed that MSNs@lip with multi-layers of phospholipids greatly reduced the friction coefficient in comparison with MSNs. Additionally, MSNs@lip demonstrated sustained drug release behavior and were biocompatible based on CCK-8 assay using MC3T3-E1 cells. The MSNs@lip developed in the present study, acting as effective lubricating drug nanocarriers, may represent a promising strategy to treat early stage OA by lubrication enhancement and drug delivery therapy.

  16. Reducing Friction and Wear of Tribological Systems through Hybrid Tribofilm Consisting of Coating and Lubricants

    Directory of Open Access Journals (Sweden)

    Shuichiro Yazawa

    2014-06-01

    Full Text Available The role of surface protective additives becomes vital when operating conditions become severe and moving components operate in a boundary lubrication regime. After protecting film is slowly removed by rubbing, it can regenerate through the tribochemical reaction of the additives at the contact. However, there are limitations about the regeneration of the protecting film when additives are totally consumed. On the other hand, there are a lot of hard coatings to protect the steel surface from wear. These can enable the functioning of tribological systems, even in adverse lubrication conditions. However, hard coatings usually make the friction coefficient higher, because of their high interfacial shear strength. Amongst hard coatings, diamond-like carbon (DLC is widely used, because of its relatively low friction and superior wear resistance. In practice, conventional lubricants that are essentially formulated for a steel/steel surface are still used for lubricating machine component surfaces provided with protective coatings, such as DLCs, despite the fact that the surface properties of coatings are quite different from those of steel. It is therefore important that the design of additive molecules and their interaction with coatings should be re-considered. The main aim of this paper is to discuss the DLC and the additive combination that enable tribofilm formation and effective lubrication of tribological systems.

  17. Lubricated sliding wear behaviour of Ni-P-W multilayered alloy coatings produced by pulse plating

    DEFF Research Database (Denmark)

    Panagopoulos, C. N.; Papachristos, V. D.; Christoffersen, Lasse

    2000-01-01

    The lubricated sliding wear behaviour of Ni-P-W multilayered alloy coatings sliding against hardened steel discs was studied, in a pin-on-disc set-up. The multilayered coatings had been deposited on mild steel pins by pulse plating and they consisted of ternary Ni-P-W layers of high and low W con...... lubrication regimes. The wear mechanisms in each lubrication regime were studied and in mixed lubrication regime, the effect of normal load and sliding speed on wear volume and friction coefficient was also studied. (C) 2000 Elsevier Science S.A. All rights reserved....

  18. TiN-Coating Effects on Stainless Steel Tribological Behavior Under Dry and Lubricated Conditions

    Science.gov (United States)

    Zhang, Liqiang; Yang, Huisheng; Pang, Xiaolu; Gao, Kewei; Tran, Hai T.; Volinsky, Alex A.

    2014-04-01

    The tribological properties of magnetron sputtered titanium nitride coating on 316L steel, sliding against Si3N4 ceramic ball under dry friction and synthetic perspiration lubrication, were investigated. The morphology of the worn surface and the elemental composition of the wear debris were examined by scanning electron microscopy and energy dispersive spectroscopy. TiN coatings and 316L stainless steel had better tribological properties under synthetic perspiration lubrication than under dry friction. Among the three tested materials (316L, 1.6 and 2.4 μm TiN coatings), 2.4 μm TiN coating exhibits the best wear resistance. The difference in wear damage of the three materials is essentially due to the wear mechanisms. For the TiN coating, the damage is attributed to abrasive wear under synthetic perspiration lubrication and the complex interactive mechanisms, including abrasive and adhesive wear, along with plastic deformation, under dry friction.

  19. Phospholipid-Coated Mesoporous Silica Nanoparticles Acting as Lubricating Drug Nanocarriers

    OpenAIRE

    Tao Sun; Yulong Sun; Hongyu Zhang

    2018-01-01

    Osteoarthritis (OA) is a severe disease caused by wear and inflammation of joints. In this study, phospholipid-coated mesoporous silica nanoparticles (MSNs@lip) were prepared in order to treat OA at an early stage. The phospholipid layer has excellent lubrication capability in aqueous media due to the hydration lubrication mechanism, while mesoporous silica nanoparticles (MSNs) act as effective drug nanocarriers. The MSNs@lip were characterized by scanning electron microscope, transmission el...

  20. 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

  1. 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.

  2. Wear Characteristics of Ceramic Coating Materials by Plasma Spray under the Lubricative Environment

    International Nuclear Information System (INIS)

    Kim, Chang Ho

    2001-02-01

    This paper is to investigate the wear behaviors of two types of ceramics, Al 2 O 3 and TiO 2 , by coated plasma thermal spray method under the lubricative environment. The lubricative environments are grease fluids, a general hydraulic fluids, and bearing fluids. The wear testing machine used a pin on disk type. Wear characteristics, which were friction force, friction coefficient and the specific wear rate, according to the lubricative environments were obtained at the four kinds of load, and the sliding velocity is 0.2m/sec. After the wear experiments, the wear surfaces of the each test specimen were observed by a scanning electronic microscope. The obtained results are as follows. : 1. The friction coefficients of TiO 2 coating materials are 0.11 ∼ 0.16 range and those of Al 2 O 3 are 0.24 ∼ 0.39. The friction coefficient of two coating materials is relative to the hardness of these materials. 2. The friction coefficient of TiO 2 coating materials in three lubricative environments is almost same to each other in spite of changing of applied loads. 3. The friction coefficient of Al 2 O 3 coating materials is more large in low load than high load. And the friction coefficient in grease is more large than a general hydraulic and bearing fluids had almost same friction coefficient. 4. The specific wear rate in TiO 2 is greatly increasing according to change the applied loads, but that in Al 2 O 3 is slightly. And the wear in grease is the least among three lubricating environments. 5. On the wear mechanism by SEM image observation, the wear of Al 2 O 3 is adhesive wear and TiO 3 is abrasive wear

  3. 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

  4. The interaction between diamond like carbon (DLC coatings and ionic liquids under boundary lubrication conditions

    Directory of Open Access Journals (Sweden)

    K. Milewski

    2017-01-01

    Full Text Available The aim of the study was to analyse antiwear DLC coatings produced by physical vapour deposition. The a-C:H coatings were deposited on steel elements designed to operate under friction conditions. The coating structure was studied by observing the surface topography with a scanning electron microscope (SEM and a profilometer. The friction and wear properties of the coatings were examined using a ball-on-disc tribotester. The lubricants tested were two types of ionic liquids (1-butyl-3-methylimidazolium tetrafluoroborate and trihexyltetradecylphosphonium bis(trifluoromethy-lsulphonyl amide. The experimental data was used to select ionic liquids with the best tribological properties to operate under lubricated friction conditions and interact with DLC coatings.

  5. 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

  6. Ultra Low Friction of DLC Coating with Lubricant

    International Nuclear Information System (INIS)

    Kano, M; Yoshida, K

    2010-01-01

    The objective of this study was to find a trigger to make clear a mechanism of the ultra low friction by evaluating the friction property of DLC-DLC combination under lubrication with the simple fluid. The Pin-on-disc reciprocating and rotating sliding tests were conducted to evaluate the friction property. The super low friction property of pure sliding with the ta-C(T) pair coated by the filtered arc deposition process under oleic acid lubrication was found at the mixed lubrication condition. It was thought that the low share strength tribofilm composed of water and acid seemed to be formed on ta-C sliding interface. Additionally, the smooth sliding surface formed on ta-C(T) was seemed to be required to keep this tribofilm. Then, the super low friction was thought to be obtained by this superlubrication condition. Although the accurate and direct experimental data must be required to make clear this super low friction mechanism, the advanced effect obtained by the simple material combination is expected to be applied on the large industrial fields in near future.

  7. 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

  8. 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.

  9. Tribological behavior of the carbon fiber reinforced polyphenylene sulfide (PPS) composite coating under dry sliding and water lubrication

    International Nuclear Information System (INIS)

    Xu Haiyan; Feng Zhizhong; Chen Jianmin; Zhou Huidi

    2006-01-01

    Carbon fiber reinforced polyphenylene sulphide (PPS) composite coatings (the mass fraction of the carbon fiber varied from 1 to 5 wt%) were prepared by flame spraying. The microstructure and physical properties of the composite coating were studied. The friction and wear characteristics of the PPS coating and carbon fiber reinforced PPS composite coating under dry- and water-lubricated sliding against stainless steel were comparatively investigated using a block-ring tester. The composite coatings showed lower friction coefficient and higher wear rate than pure PPS coatings under dry sliding. Under water-lubricated condition, the composite coatings showed better wear resistance than under dry. Under water-lubricated condition the tribological behaviors of the 3 wt% carbon fiber reinforced composite coating also were investigated under different sliding speed and load. The result showed that the sliding speed had little effect on the tribological properties, but the load affected greatly on that of the composite coatings. The morphologies of the worn surfaces of the composite coatings and the counterpart steel were analyzed by means of scanning electron microscopy (SEM), coupled with an energy-dispersive X-ray spectrometer (EDS) for compositional analysis

  10. Tribological Performance of Hydrogenated Amorphous Carbon (a-C: H DLC Coating when Lubricated with Biodegradable Vegetal Canola Oil

    Directory of Open Access Journals (Sweden)

    H.M. Mobarak

    2014-06-01

    Full Text Available Increasing environmental awareness and demands for lowering energy consumptions are strong driving forces behind the development of the vehicles of tomorrow. Without the advances of lubricant chemistry and adequate lubricant formulation, expansion of modern engines would not have been possible. Considering environmental awareness factors as compared to mineral oils, vegetal oil based biolubricants are renewable, biodegradable, non-toxic and have a least amount of greenhouse gases. Furthermore, improvement in engine performance and transmission components, which were impossible to achieve by applying only lubricants design, is now possible through diamond like carbon (DLC coatings. DLC coatings exhibit brilliant tribological properties, such as good wear resistance and low friction. In this regard, tribological performance of a-C: H DLC coating when lubricated with Canola vegetal oil has been investigated by the help of a ball-on-flat geometry. Experimental results demonstrated that the a-C: H DLC coating exhibited better performance with Canola oil in terms of friction and wear as compared to the uncoated materials. Large amount of polar components in the Canola oil significantly improved the tribological properties of the a-C:H coating. Thus, usage of a-C: H DLC coating with Canola oil in the long run may have a positive impact on engine life.

  11. Investigation on Nano-Self-Lubricant Coating Synthesized by Laser Cladding and Ion Sulfurization

    Directory of Open Access Journals (Sweden)

    Meiyan Li

    2015-01-01

    Full Text Available The composite processing between laser cladding and low temperature (300°C ion sulfurization was applied to prepare wear resistant and self-lubricating coating. The microstructure, morphology, phase composition, valence states, and wear resistance of the composite coating were investigated by scanning electron microscopy (SEM, atomic force microscope (AFM, X-ray diffraction (XRD, X-ray photoelectron spectroscope (XPS, and friction and wear apparatus. The results indicate that the laser cladding Ni-based coatings and the maximum hardness of 46.5 HRC were obtained when the percent of pure W powder was 10%, composed of columnar dendrites crystals and ultrafine dendritic structure. After ion sulfurization at 300°C for 4 h, the loose and porous composite coating is formed with nanograins and the granularity of all grains is less than 100 nm, which consists of γ-(Fe, Ni, M23C6 carbides, FeS, FeS2, and WS2. Furthermore, the wear resistance of the composite coating is better than the laser cladding Ni55 + 10%W coating, and the friction coefficient and mass losses under the conditions of dry and oil lubrication are lower than those of laser cladding Ni55 + 10%W coating.

  12. 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.

  13. Wear of tin coating and Al-Si alloy substrate against carburized steel under mixed lubrication

    Science.gov (United States)

    Wang, Q.; Cheng, H. S.; Fine, M. E.

    1994-04-01

    Tin coatings on Al-Si alloys are widely used in the automotive industries. The soft tin coating and the harder substrate alloy form a tribological system with the advantages of low friction and reasonably high load-bearing capacity. Wear tests of tin coated Al-Si Z332 alloy in conformal contact against carburized 1016 steel have been carried out under mixed lubrications with SAE 10W30 oil to study the wear mechanisms. Two major wear mechanisms, uniform wear of the tin coating due to micro-plowing and spall pitting related to the substrate are found to contribute to the bearing material loss when the fluid lubrication film is relatively thick (Lambda about 1.6). Under conditions of thinner films (Lambda approximately = 0.8), some local coating debonding occurs. The pitting and local coating debounding are closely related to fracture in the substrate. The bonding between silicon and tin seems to be weaker than between aluminum and tin. During wear, oxidation occurs.

  14. 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)

  15. Influence of W content on tribological performance of W-doped diamond-like carbon coatings under dry friction and polyalpha olefin lubrication conditions

    International Nuclear Information System (INIS)

    Fu, Zhi-qiang; Wang, Cheng-biao; Zhang, Wei; Wang, Wei; Yue, Wen; Yu, Xiang; Peng, Zhi-jian; Lin, Song-sheng; Dai, Ming-jiang

    2013-01-01

    Highlights: • W-doped DLC coating with various W contents was fabricated. • Friction and wear of DLC coated sample was studied. • The lubricant additive was T307. • The influence of W content on friction under lubrication was unveiled. • The influence of W content on wear under lubrication was studied. - Abstract: The influence on tungsten content on the structure, mechanical properties and tribological performance of W-doped diamond-like carbon (DLC) coatings was studied by X-ray photoelectron spectroscopy, nano-indentation, scratch test, and ball-on-disk friction test. It was found that with increasing W content, the content of WC and free W in the coatings is increased while the content of sp 3 -C in the coatings is decreased. The effect of W content on the hardness and elastic modulus of the coatings is indistinctive, but there exists the highest critical load of scratch test of above 100 N when W content is 3.08 at.%. With the increase of W content, the friction coefficients of W-doped DLC coatings under dry friction conditions are increased while the friction coefficients of W-doped DLC coatings under polyalpha olefin (PAO) lubrication are decreased. With the increase of W content, the wear rates of the DLC-coated samples under dry friction conditions show a minimum value; under pure PAO lubrication, the influence of W content on the wear rates of the DLC-coated samples is indistinctive when the W content is below 10.73 at.% while the wear rates are increased with increasing W content from 10.73 at.% to 24.09 at.%; when lubricated by PAO + thiophosphoric acid amine (T307) salt, the samples coated with the undoped DLC or the W-doped DLC with high W content exhibit low wear rates

  16. 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

  17. 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.

  18. Annual Report - Compatibility of ZDDP and ionic liquid anti-wear additives with hard coatings for engine lubrications

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Jun [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Zhou, Yan [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Leonard, Donovan N [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Meyer, III, Harry M [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Luo, Huimin [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-03-01

    The objectives for this considerations described here are to; investigate the compatibility of engine lubricant antiwear (AW) additives, specifically conventional zinc dialkyldithiophosphate (ZDDP) and newly developed ionic liquids (ILs), with selected commercial hard coatings, and provide fundamental understanding to guide future development of engine lubricants.

  19. Preparation and tribological properties of self-lubricating TiO2/graphite composite coating on Ti6Al4V alloy

    International Nuclear Information System (INIS)

    Mu, Ming; Zhou, Xinjian; Xiao, Qian; Liang, Jun; Huo, Xiaodi

    2012-01-01

    Highlights: ► A TiO 2 /graphite composite coating is produced on Ti alloy by one-step PEO process. ► The TiO 2 /graphite composite coating exhibits excellent self-lubricating behavior. ► The self-lubricating composite coating improves the wear resistance by comparison to the conventional PEO coating. - Abstract: One-step plasma electrolytic oxidation (PEO) process in a graphite-dispersed phosphate electrolyte was used to prepare a graphite-containing oxide composite coating on Ti6Al4V alloy. The composition and microstructure of the oxide coatings produced in the phosphate electrolytes with and without addition of graphite were analyzed by X-ray diffractometer (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The tribological properties of the uncoated Ti6Al4V alloy and oxide coatings were evaluated using a reciprocating ball-on-disk tribometer. Results showed that the graphite-containing oxide composite coating can be successfully produced on Ti6Al4V alloy in the graphite-dispersed phosphate electrolyte using PEO process. The graphite-containing oxide composite coating registered much lower friction coefficient and wear rate than the uncoated Ti6Al4V alloy and the oxide coating without graphite under dry sliding condition, exhibiting excellent self-lubricating property.

  20. 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

  1. 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.

  2. Surface investigation and tribological mechanism of a sulfate-based lubricant deposited on zinc-coated steel sheets

    Energy Technology Data Exchange (ETDEWEB)

    Timma, Christian, E-mail: christian.timma@thyssenkrupp.com [ThyssenKrupp Steel Europe AG, Technology & Innovation, Kaiser-Wilhelm Str. 100, 47166 Duisburg (Germany); University of Duisburg-Essen, Faculty of Chemistry, CENIDE, Universitätsstraße 7, 45141 Essen (Germany); Lostak, Thomas; Janssen, Stella; Flock, Jörg [ThyssenKrupp Steel Europe AG, Technology & Innovation, Kaiser-Wilhelm Str. 100, 47166 Duisburg (Germany); Mayer, Christian [University of Duisburg-Essen, Faculty of Chemistry, CENIDE, Universitätsstraße 7, 45141 Essen (Germany)

    2016-12-30

    Highlights: • Skin-passed hot-dip galvanized (HDG-) steel sheets were coated with (NH{sub 4}){sub 2}SO{sub 4} in a common roll-coating method. • A formation of (NH{sub 4}){sub 2}Zn(SO{sub 4}) * xH{sub 2}O was observed and the reaction mainly occurred in the skin-passed areas of the surface. • Sulfate coated samples reveal a superior friction behaviour in oil-like conditions compared non-sulfated specimen. - Abstract: Phosphatation is a well-known technique to improve friction and wear behaviour of zinc coated steel, but has a variety of economic and ecologic limitations. In this study an alternative coating based on ammonium sulfate ((NH{sub 4}){sub 2}SO{sub 4}) is applied on skin-passed hot-dip galvanized steel sheets in order to investigate its surface chemical and tribological behaviour in a Pin-on-Disk Tribometer. Raman- and X-ray photoelectron spectroscopic results revealed a formation of ammonium zinc sulfate ((NH{sub 4}){sub 2}Zn(SO{sub 4}){sub 2} * xH{sub 2}O) on the surface, which is primarily located in the skin-passed areas of the steel material. Sulfate coated samples exhibited a superior friction behaviour in Pin-on-Disk Tests using squalane as a model substance for oil-like lubricated conditions and a formation of a thin lubrication film is obtained in the wear track. Squalane acts as a carrier substance for ammonium zinc sulfate, leading to an effective lubrication film in the wear track.

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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)

  9. 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.)

  10. 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.

  11. Fabrication and evaluation of atmospheric plasma spraying WC-Co-Cu-MoS2 composite coatings

    International Nuclear Information System (INIS)

    Yuan Jianhui; Zhu Yingchun; Zheng Xuebing; Ji Heng; Yang Tao

    2011-01-01

    Research highlights: → Protective WC-Co-based coatings containing solid lubricant Cu and MoS 2 used in wear applications were investigated in this study. → It was found that the MoS 2 composition in the feed powder was kept in WC-Co-Cu-MoS 2 coatings, and the decomposition and decarburization of WC in APS process were improved. → Combining the wear resistance of WC with the lubricating properties of Cu and MoS 2 has an extremely beneficial effect on improving the tribological performance of the resulting coating. - Abstract: Protective WC-Co-based coatings containing solid lubricant Cu and MoS 2 used in wear applications were investigated in this study. These coatings were deposited on mild steel substrates by atmospheric plasma spraying (APS). The feedstock powders were prepared by mechanically mixing the solid lubricant powders and WC-Co powder, followed by sintering and crushing the mixtures to avoid different particle flighting trajectories at plasma. The tribological properties of the coatings against stainless steel balls were examined by ball-on-disk (BOD) tribometer under normal atmospheric condition. The microstructure of the coatings was studied by optical microscope, scanning electron microscope and X-ray diffraction. It was found that the MoS 2 composition in the feed powder was kept in WC-Co-Cu-MoS 2 coatings, and the decomposition and decarburization of WC in APS process were improved, which were attributed to the protection of Cu around them. The friction and wear behaviors of all the WC-Co-Cu-MoS 2 coatings were superior to that of WC-Co coating. Such behavior was associated to different wear mechanisms operating for WC-Co coating and the WC-Co-Cu-MoS 2 coatings.

  12. 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.

  13. 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.

  14. Fabrics coated with lubricated nanostructures display robust omniphobicity

    International Nuclear Information System (INIS)

    Shillingford, Cicely; MacCallum, Noah; Wong, Tak-Sing; Kim, Philseok; Aizenberg, Joanna

    2014-01-01

    The development of a stain-resistant and pressure-stable textile is desirable for consumer and industrial applications alike, yet it remains a challenge that current technologies have been unable to fully address. Traditional superhydrophobic surfaces, inspired by the lotus plant, are characterized by two main components: hydrophobic chemical functionalization and surface roughness. While this approach produces water-resistant surfaces, these materials have critical weaknesses that hinder their practical utility, in particular as robust stain-free fabrics. For example, traditional superhydrophobic surfaces fail (i.e., become stained) when exposed to low-surface-tension liquids, under pressure when impacted by a high-velocity stream of water (e.g., rain), and when exposed to physical forces such as abrasion and twisting. We have recently introduced slippery lubricant-infused porous surfaces (SLIPS), a self-healing, pressure-tolerant and omniphobic surface, to address these issues. Herein we present the rational design and optimization of nanostructured lubricant-infused fabrics and demonstrate markedly improved performance over traditional superhydrophobic textile treatments: SLIPS-functionalized cotton and polyester fabrics exhibit decreased contact angle hysteresis and sliding angles, omni-repellent properties against various fluids including polar and nonpolar liquids, pressure tolerance and mechanical robustness, all of which are not readily achievable with the state-of-the-art superhydrophobic coatings. (paper)

  15. Fabrics coated with lubricated nanostructures display robust omniphobicity

    Science.gov (United States)

    Shillingford, Cicely; MacCallum, Noah; Wong, Tak-Sing; Kim, Philseok; Aizenberg, Joanna

    2014-01-01

    The development of a stain-resistant and pressure-stable textile is desirable for consumer and industrial applications alike, yet it remains a challenge that current technologies have been unable to fully address. Traditional superhydrophobic surfaces, inspired by the lotus plant, are characterized by two main components: hydrophobic chemical functionalization and surface roughness. While this approach produces water-resistant surfaces, these materials have critical weaknesses that hinder their practical utility, in particular as robust stain-free fabrics. For example, traditional superhydrophobic surfaces fail (i.e., become stained) when exposed to low-surface-tension liquids, under pressure when impacted by a high-velocity stream of water (e.g., rain), and when exposed to physical forces such as abrasion and twisting. We have recently introduced slippery lubricant-infused porous surfaces (SLIPS), a self-healing, pressure-tolerant and omniphobic surface, to address these issues. Herein we present the rational design and optimization of nanostructured lubricant-infused fabrics and demonstrate markedly improved performance over traditional superhydrophobic textile treatments: SLIPS-functionalized cotton and polyester fabrics exhibit decreased contact angle hysteresis and sliding angles, omni-repellent properties against various fluids including polar and nonpolar liquids, pressure tolerance and mechanical robustness, all of which are not readily achievable with the state-of-the-art superhydrophobic coatings.

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. Wear resistant PVD-/CVD-dry lubricant coatings for the environmental and innovative production. Subproject 3: dry lubricant coatings - carbon coatings. Final report; Verschleissfeste PVD-/CVD-Trockenschmierstoffschichten fuer die umweltschonende und innovative Fertigung. Teilprojekt 3: Kohlenstoffbasierte Trockenschmierstoffschichten (TSS-C). Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Schattke, A.; Hockauf, W.

    2002-09-05

    The partners Bosch, Metaplas Ionon and Roth and Rau developed dry lubricant coatings on a carbon coating base. The cutting tools used for the testing were developed in former dry cutting projects especially for cutting with minimum quantity lubrication (MQL). The coatings were tested in cutting and metal forming. After tribological testing at the coating companies the deposited coatings were evaluated by machining tests in drilling, thread forming and metal forming at the universities of Darmstadt and Kassel. The best coatings were tested in production field tests (laboratory) or, if possible, in the production at company Bosch and at other end users of the joint project. It was possible to show that carbon coatings are very good at punching and sheet bending. Also at drilling and thread forming in cast iron and low alloyed steels the results are good enough for production. The results at drilling and thread forming in aluminium alloys and high alloyed steels (X90CrMoV18) were not good enough for production under dry conditions. But testing with a reduced amount of MQL (6ml/h) showed better cutting parameters than commercial coatings. Also cutting length and quality of the parts are better. Even with the best coatings it was not possible to make dry massive forming with reduced temperature. At these high temperatures and high surface pressures it was not possible to work without lubricants. (orig.) [German] Im Projekt wurden von den Partnern Bosch, Metaplas Ionon und Roth and Rau Trockenschmierstoffschichten auf Kohlenstoffbasis entwickelt. Diese wurden auf Werkzeuge abgeschieden, deren Geometrien in bereits abgeschlossenen Projekten fuer die Trockenzerspannung mit Minimalmengenschmierung optimiert wurden. Die Schichten sind fuer die Zerspannung und Umformtechnik vorgesehen. An tribologische Tests bei den Beschichtern schlossen sich Filtertests an den Hochschulen Darmstadt und Kassel an, bei denen die Schichten in Bohr-, Gewindeform- und Umformtests untersucht

  1. 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

  2. Development of surface coatings for air-lubricated, compliant journal bearings to 650 C

    Science.gov (United States)

    Bhushan, B.; Gray, S.

    1978-01-01

    Surface coatings for an air-lubricated, compliant journal for an automotive gas turbine engine were tested to find those capable of withstanding temperatures of either 540 C (1000 F) or 650 C (1200 F). Also, the coatings have to be capable of surviving the start-stop sliding contact cycles prior to rotor lift-off and at touchdown. Selected coating combinations were tested in start-stop tests at 14 kPa (2 psi) loading for 2000 cycles at room and maximum temperatures. Specific coating recommendations are: Cdo and graphite on foil versus chrome carbide on journal up to 370 C (700 F); NASA PS-120 (Tribaloy 400, silver, and CaF2) on journal versus uncoated foil up to 540 C (1000 F); and chemically adherent Cr2O3 on journal and foil up to 650 C (1200 F). The chemically adherent Cr2O3 coating system was further tested successfully at 35 kPa (5 psi) loading for 2000 start-stop cycles.

  3. 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

  4. Optimization of wear behavior of electroless Ni-P-W coating under dry and lubricated conditions using genetic algorithm (GA

    Directory of Open Access Journals (Sweden)

    Arkadeb Mukhopadhyay

    2016-12-01

    Full Text Available The present study aims to investigate the tribological behavior of Ni-P-W coating under dry and lubricated condition. The coating is deposited onto mild steel (AISI 1040 specimens by the electroless method using a sodium hypophosphite based alkaline bath. Coating characterization is done to investigate the effect of microstructure on its performance. The change in microhardness is observed to be quite significant after annealing the deposits at 400°C for 1h. A pin–on–disc type tribo-tester is used to investigate the tribological behavior of the coating under dry and lubricated conditions. The experimental design formulation is based on Taguchi’s orthogonal array. The design parameters considered are the applied normal load, sliding speed and sliding duration while the response parameter is wear depth. Multiple regression analysis is employed to obtain a quadratic model of the response variables with the main design parameters under considerations. A high value of coefficient of determination of 95.3% and 87.5% of wear depth is obtained under dry and lubricated conditions, respectively which indicate good correlation between experimental results and the multiple regression models. Analysis of variance at a confidence level of 95% shows that the models are statistically significant. Finally, the quadratic equations are used as objective functions to obtain the optimal combination of tribo testing parameters for minimum wear depth using genetic algorithm (GA.

  5. Fabrication and performance tests of a prototype in-situ coating machine for JT-60

    International Nuclear Information System (INIS)

    Obara, Kenjiro; Abe, Tetsuya; Murakami, Yoshio

    1987-09-01

    Prior to the design and construction of the JT-60's in-situ coating device, a prototype machine was fabricated and tested to confirm the applicability of proposed driving methods and mechanical elements to the device which would be operated in very severe conditions including high ambient temperature and high vacuum. The machine basically consists of an in-vessel manipulator, a fiberscope and an ohmically heated titanium evaporator. From the test results, we recommended to use the combination of Inconel 625 and a self-lubricating alloy for the solid-lubricated bearings and MoS 2 -coated Inconel 625 for the solid-lubricated gears. It was also found that TiC coating showed a effect for the prevention of welding between bolts and nuts. In order to optimize the operating parameters of the machine, many wall inspection tests and titanium evaporation tests were carried out in a large vacuum vessel by simulating the JT-60 conditions. (author)

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

    Science.gov (United States)

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

    2016-03-01

    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 (WS2 and MoS2, where metals were supplied from coating and sulphur from engine oil) in the transfer layer.

  7. 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.)

  8. Microdistribution of phases and substructure of the composite electrolytic self-lubricating copper-molybdenite coating

    International Nuclear Information System (INIS)

    Pribysh, I.Z.; Bakakin, G.N.; Borzyak, A.G.; Sajfullin, R.S.

    1978-01-01

    The influence of MoS 2 particles on the substructure of a copper matrix was studied, and their location in the composition was established. It is shown that the presence of molybdenite causes a variation in the conditions of electrical crystallization of copper. The optimum composition has been found, which is used as a self-lubricating coating for friction machine parts

  9. Effect of nanoparticles as lubricant additives on friction and wear behavior of tetrahedral amorphous carbon (ta-C coating

    Directory of Open Access Journals (Sweden)

    Xiang Li

    2018-03-01

    Full Text Available As diamond like carbon (DLC coating becomes increasingly popular in providing low friction and wear under lubricated conditions, the effect of various oil additives on tribological behavior of DLC coating is drawing more attention. Various oil additives, such as ZnDTP and MoDTC, have been widely used in automobile engine industry to pursuit excellent tribological performance in the insufficient lubrication condition. Although such commercial oil additives have been proven to reduce friction or/and wear to some extent, usage of such high -SAPS (sulphuric ash, phosphor, sulfphur conventional additives is bound to arouse concerns due to environmental reasons. In this research, we investigate the effect of two nanoparticle oil additives, which are cerium oxide (CeO2 and zirconium dioxide (ZrO2, on friction and wear of non-hydrogen tetrahedral amorphous carbon (ta-C coating. The results show that by adding ZrO2 nanoparticle, the friction of DLC coating could be reduced about 32% compared to non-additive base oil scenario, but specific wear rate increases by 40%. When CeO2 nanoparticle is used, friction increases by 22% compared to non-additive base oil scenario, however wear decreases by nearly 77%.

  10. 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.

  11. Effects of Coating Materials and Processing Conditions on Flow Enhancement of Cohesive Acetaminophen Powders by High-Shear Processing With Pharmaceutical Lubricants.

    Science.gov (United States)

    Wei, Guoguang; Mangal, Sharad; Denman, John; Gengenbach, Thomas; Lee Bonar, Kevin; Khan, Rubayat I; Qu, Li; Li, Tonglei; Zhou, Qi Tony

    2017-10-01

    This study has investigated the surface coating efficiency and powder flow improvement of a model cohesive acetaminophen powder by high-shear processing with pharmaceutical lubricants through 2 common equipment, conical comil and high-shear mixer. Effects of coating materials and processing parameters on powder flow and surface coating coverage were evaluated. Both Carr's index and shear cell data indicated that processing with the lubricants using comil or high-shear mixer substantially improved the flow of the cohesive acetaminophen powder. Flow improvement was most pronounced for those processed with 1% wt/wt magnesium stearate, from "cohesive" for the V-blended sample to "easy flowing" for the optimally coated sample. Qualitative and quantitative characterizations demonstrated a greater degree of surface coverage for high-shear mixing compared with comilling; nevertheless, flow properties of the samples at the corresponding optimized conditions were comparable between 2 techniques. Scanning electron microscopy images demonstrated different coating mechanisms with magnesium stearate or l-leucine (magnesium stearate forms a coating layer and leucine coating increases surface roughness). Furthermore, surface coating with hydrophobic magnesium stearate did not retard the dissolution kinetics of acetaminophen. Future studies are warranted to evaluate tableting behavior of such dry-coated pharmaceutical powders. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  12. 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

  13. Tribology and Microstructure of PS212 with a Cr2O3 Seal Coat

    Science.gov (United States)

    Sliney, Harold E.; Benoy, Patricia A.; Korenyi-Both, Andras; Dellacorte, Christopher

    1994-01-01

    PS212 is a plasma sprayed metal bonding chrome carbide coating with solid lubricant additives which has lubricating properties at temperatures up to about 900 deg C. The coating is diamond ground to achieve an acceptable tribological surface. But, as with many plasma spray coatings, PS212 is not fully-dense. In this study, a chromium oxide base seal coating is used in an attempt to seal any porosity that is open to the surface of the PS212 coating, and to study the effect of the sealant on the tribological properties of PS212. The results indicate that the seal coating reduces friction and wear when it is applied and then diamond ground leaving a thin layer of seal coating which fills in the surface pits of the PS212 coating.

  14. 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

  15. Diamond-like carbon coating under oleic acid lubrication: Evidence for graphene oxide formation in superlow friction

    Science.gov (United States)

    de Barros Bouchet, Maria Isabel; Martin, Jean Michel; Avila, José; Kano, Makoto; Yoshida, Kentaro; Tsuruda, Takeshi; Bai, Shandan; Higuchi, Yuji; Ozawa, Nobuki; Kubo, Momoji; Asensio, Maria C.

    2017-04-01

    The achievement of the superlubricity regime, with a friction coefficient below 0.01, is the Holy Grail of many tribological applications, with the potential to have a remarkable impact on economic and environmental issues. Based on a combined high-resolution photoemission and soft X-ray absorption study, we report that superlubricity can be realized for engineering applications in bearing steel coated with ultra-smooth tetrahedral amorphous carbon (ta-C) under oleic acid lubrication. The results show that tribochemical reactions promoted by the oil lubrication generate strong structural changes in the carbon hybridization of the ta-C hydrogen-free carbon, with initially high sp3 content. Interestingly, the macroscopic superlow friction regime of moving mechanical assemblies coated with ta-C can be attributed to a few partially oxidized graphene-like sheets, with a thickness of not more than 1 nm, formed at the surface inside the wear scar. The sp2 planar carbon and oxygen-derived species are the hallmark of these mesoscopic surface structures created on top of colliding asperities as a result of the tribochemical reactions induced by the oleic acid lubrication. Atomistic simulations elucidate the tribo-formation of such graphene-like structures, providing the link between the overall atomistic mechanism and the macroscopic experimental observations of green superlubricity in the investigated ta-C/oleic acid tribological systems.

  16. 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...

  17. 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

  18. 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)

  19. 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.

  20. Effect of triangular texture on the tribological performance of die steel with TiN coatings under lubricated sliding condition

    Science.gov (United States)

    Chen, Ping; Xiang, Xin; Shao, Tianmin; La, Yingqian; Li, Junling

    2016-12-01

    The friction and wear of stamping die surface can affect the service life of stamping die and the quality of stamping products. Surface texturing and surface coating have been widely used to improve the tribological performance of mechanical components. This study experimentally investigated the effect of triangular surface texture on the friction and wear properties of the die steel substrate with TiN coatings under oil lubrication. TiN coatings were deposited on a die steel (50Cr) substrate through a multi-arc ion deposition system, and then triangular surface texturing was fabricated by a laser surface texturing. The friction and wear test was conducted by a UMT-3 pin-on-disk tribometer under different sliding speeds and different applied loads, respectively. The adhesion test was performed to evaluate the effectiveness of triangular texturing on the interfacial bonding strength between the TiN coating and the die steel substrate. Results show that the combination method of surface texturing process and surface coating process has excellent tribological properties (the lowest frictional coefficient and wear volume), compared with the single texturing process or the single coating process. The tribological performance is improved resulting from the high hardness and low elastic modulus of TiN coatings, and the generation of hydrodynamic pressure, function of micro-trap for wear debris and micro-reservoirs for lubricating oil of the triangular surface texture. In addition, the coating bonding strength of the texturing sample is 3.63 MPa, higher than that of the single coating sample (3.48 MPa), but the mechanisms remain to be further researched.

  1. Lubricating Properties of Ceramic-Bonded Calcium Fluoride Coatings on Nickel-Base Alloys from 75 to 1900 deg F

    Science.gov (United States)

    Sliney, Harold E.

    1962-01-01

    The endurance life and the friction coefficient of ceramic-bonded calcium fluoride (CaF2) coatings on nickel-base alloys were determined at temperatures from 75 F to 1900 F. The specimen configuration consisted of a hemispherical rider (3/16-in. rad.) sliding against the flat surface of a rotating disk. Increasing the ambient temperature (up to 1500 F) or the sliding velocity generally reduced the friction coefficient and improved coating life. Base-metal selection was critical above 1500 F. For instance, cast Inconel sliding against coated Inconel X was lubricated effectively to 1500 F, but at 1600 F severe blistering of the coatings occurred. However, good lubrication and adherence were obtained for Rene 41 sliding against coated Rene 41 at temperatures up to 1900 F; no blisters developed, coating wear life was fairly good, and the rider wear rate was significantly lower than for the unlubricated metals. Friction coefficients were 0.12 at 1500 F, 0.15 at 1700 F, and 0.17 at 1800 F and 1900 F. Because of its ready availability, Inconel X appears to be the preferred substrate alloy for applications in which the temperature does not exceed 1500 F. Rene 41 would have to be used in applications involving higher temperatures. Improved coating life was derived by either preoxidizing the substrate metals prior to the coating application or by applying a very thin (less than 0.0002 in.) burnished and sintered overlay to the surface of the coating. Preoxidation did not affect the friction coefficient. The overlay generally resulted in a higher friction coefficient than that obtained without the overlay. The combination of both modifications resulted in longer coating life and in friction coefficients intermediate between those obtained with either modification alone.

  2. 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.

  3. Preparation and Tribological Properties of Dual-Coated TiO2 Nanoparticles as Water-Based Lubricant Additives

    Directory of Open Access Journals (Sweden)

    Yue Gu

    2014-01-01

    Full Text Available Titanium dioxide nanoparticles (TiO2 were synthesized and then dual-coated with silane coupling agent (KH-570 and OP-10 in sequence in order to be dispersed stably in water as lubricant additives. The tribological properties and the application performance in Q235 steel machining of the nanoparticles as water-based lubricant additives were investigated on an MSR-10D four-ball tribotester and on a bench drilling machine, respectively. Scanning electron microscope (SEM and atomic force microscope (AFM were used to analyze the worn surface. The results show that the surface-modified TiO2 nanoparticles can remarkably improve the load-carrying capacity, the friction reducing, and anti wear abilities of pure water. The wear scar diameter and the coefficient of friction of the water-based lubricating fluids with TiO2 nanoparticles decreased, and the thick deep furrows on the surface of wear scar also decreased obviously with the increase of TiO2 concentration. The power consumption in drilling process was lower and the cutting surface was smoother using the water-based lubricating fluids added TiO2 nanoparticles compared to the fluid without addition. The reason for nanoparticles improving tribological properties of water based lubricating fluid might be the formation of a dynamic deposition film during rubbing process according to analysis of the worn surface.

  4. Lubrication of ceramics in ring/cylinder applications

    International Nuclear Information System (INIS)

    Gaydos, P.A.; Dufrane, K.F.

    1989-01-01

    In support of efforts to apply ceramics to advanced heat engines, a study was performed of the wear mechanisms of ceramics at the ring/cylinder interface. A laboratory apparatus was constructed to reproduce most of the conditions of an actual engine but used easily prepared ring and cylinder specimens to facilitate their fabrication. Plasma-sprayed coatings of Cr 2 O 3 and hypersonic flame-sprayed coatings of cobalt-bonded WC performed particularly well as ring coatings. Similar performance was obtained with these coatings operating against SiC, Si 3 N 4 , SiC whisker-reinforced Al 2 O 3 and Cr 2 O 2 coatings. The study demonstrated the critical need for lubrication and evaluated the performance of two available lubricants

  5. An investigation of material properties and tribological performance of magnetron sputtered thin film coatings

    Science.gov (United States)

    Singh, Harpal

    This dissertation is divided into two categories based upon lubrication functionality and its application. The categories are: Dry film lubrication and Fluid film lubrication with thin film coatings. Thin film coatings examined in this work were deposited using closed field unbalanced magnetron sputtering and RF-DC coupled magnetron sputtering systems. In Dry/Solid film lubrication, the mechanical, structural and tribological properties of two Molybdenum disulphide (MoS2) based coatings are examined and evaluated. Among the two coatings, one coating is doped with Ti (Ti-MoS2) and the other is a combination of metal, lubricant and oxide (Sb2O3/Au - MoS2). These coatings are known to provide low friction in vacuum environments. The goal of this work was to evaluate friction and wear performance of MoS2 doped coatings in unidirectional and reciprocating sliding contact under different environmental conditions. Sliding contact results showed friction and wear dependence on temperature and humidity. The formation and removal of transfer films and the recrystallization and reorientation of basal layers on the steel counterface was observed as the mechanism for low friction. Structural analysis revealed a relationship between the microstructural properties and tribological performance. It was also observed that the addition of dopants (Ti, Au, Sb 2O3) improved the mechanical properties as compared to pure MoS2 coatings. Further, the rolling contact performance of the coatings was measured on a five ball on rod tribometer and a Thrust bearing tribometer under vacuum and air environments. The rolling contact experiments indicated that life of the rolling components depend on the amount of material present between the contacts. Fluid film lubrication with thin film coatings investigates the possibilities to improve the performance and durability of tribological components when oils and thin films are synergistically coupled. In this work, the ability of a Diamond Like Carbon

  6. 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.

  7. 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....

  8. 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.

  9. The tribology of PS212 coatings and PM212 composites for the lubrication of titanium 6Al-4V components of a Stirling engine space power system

    Science.gov (United States)

    Sliney, Harold E.; Lukaszewicz, Victor; Dellacorte, Christopher

    1994-01-01

    The Stirling space power machine incorporates a linear alternator to generate electrical power. The alternator is a reciprocating device that is driven by a solar or nuclear-powered Stirling engine. The power piston and cylinder are made of titanium 6Al-4V (Ti6-4) alloy, and are designed to be lubricated by a hydrodynamically-generated gas film. Rubbing occurs during starts and stops and there is the possibility of an occasional high speed rub. Since titanium is known to have a severe galling tendency in sliding contacts, a 'back-up', self-lubricating coating on the cylinder and/or the piston is needed. This report describes the results of a research program to study the lubrication of Ti6-4 with the following chromium carbide based materials: plasma-sprayed PS212 coatings and sintered PM212 counterfaces. Program objectives are to achieve adherent coatings on Ti6-4 and to measure the friction and wear characteristics of the following sliding combinations under conditions simulative of the Stirling-driven space power linear alternator: Ti6-4/Ti6-4 baseline, Ti6-4/PS212-coated Ti6-4, and PS212-coated Ti6-4/PM212.

  10. The Effect of Tic Coated Balls and Stress on the Lubricant Lifetime of a Synthetic Hydrocarbon (pennzane 2001A) Using a Vacuum Spiral Orbit Tribometer

    Science.gov (United States)

    Jansen, Mark J.; Jones, William R., Jr.; Pepper, Stephen V.; Wheeler, Donald R.; Schroeer, Achim; Fluehmann, Freddy; Loewenthal, Stuart H.; Shogrin, Bradley A.

    2000-01-01

    A vacuum spiral orbit rolling contact tribometer was used to determine effect of varying mean Hertzian stress (1.0, 1.5, 2.0 GPa) and the use of 440C and TiC coated 440C balls on lubricant lifetime of a synthetic hydrocarbon (Pennzane 2001A) on 440C stainless steel. Conditions included 210 rpm, approx. 50 micrograms lubricant, an initial vacuum TiC coated 440C ball showed no increase in lifetime over the 440C ball. The decreasing lifetime with increasing stress level correlated well with energy dissipation calculations.

  11. Coated carbide drill performance under soluble coconut oil lubricant and nanoparticle enhanced MQL in drilling AISI P20

    Science.gov (United States)

    Jamil, N. A. M.; Azmi, A. I.; Fairuz, M. A.

    2016-02-01

    This research experimentally investigates the performance of a TiAlN coated carbide drill bit in drilling AISI P20 through two different kinds of lubricants, namely; soluble coconut oil (SCO) and nanoparticle-enhanced coconut oil (NECO) under minimum quantity lubrication system. The tool life and tool wear mechanism were studied using various cutting speeds of 50, 100 and 150 m/min with a constant feed of 0.01 mm/rev. Since the flank wear land was not regular along the cutting edge, the average flank wear (VB) was measured at several points using image analysis software. The drills were inspected using a scanning electron microscope to further elucidate the wear mechanism. The result indicates that drilling with the nanoparticle- enhanced lubricant was better in resisting the wear and improving the drill life to some extent

  12. 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.

  13. Tribological coatings for complex mechanical elements produced by supersonic cluster beam deposition of metal dichalcogenide nanoparticles

    Science.gov (United States)

    Piazzoni, C.; Buttery, M.; Hampson, M. R.; Roberts, E. W.; Ducati, C.; Lenardi, C.; Cavaliere, F.; Piseri, P.; Milani, P.

    2015-07-01

    Fullerene-like MoS2 and WS2 nanoparticles can be used as building blocks for the fabrication of fluid and solid lubricants. Metal dichalcogenide films have a very low friction coefficient in vacuum, therefore they have mostly been used as solid lubricants in space and vacuum applications. Unfortunately, their use is significantly hampered by the fact that in the presence of humidity, oxygen and moisture, the low-friction properties of these materials rapidly degrade due to oxidation. The use of closed-cage MoS2 and WS2 nanoparticles may eliminate this problem, although the fabrication of lubricant thin films starting from dichalcogenide nanoparticles is, to date, a difficult task. Here we demonstrate the use of supersonic cluster beam deposition for the coating of complex mechanical elements (angular contact ball bearings) with nanostructured MoS2 and WS2 thin films. We report structural and tribological characterization of the coatings in view of the optimization of tribological performances for aerospace applications.

  14. The tribology of PS212 coatings and PM212 composites for the lubrication of titanium 6A1-4V components of a Stirling engine space power system

    Science.gov (United States)

    Sliney, Harold E.; Dellacorte, Christopher; Lukaszewicz, Victor

    1995-01-01

    The Stirling space power machine incorporates a linear alternator to generate electrical power. The alternator is a reciprocating device that is driven by a solar or nuclear-powered Stirling engine. The power piston and cylinder are made of titanium 6A1-4V (Ti6-4) alloy, and are designed to be lubricated by a hydrodynamically-generated gas film. Rubbing occurs during starts and stops and there is a possibility of an occasional high speed rub. Since titanium is known to have a severe galling tendency in sliding contacts, a 'backup,' self-lubricating coating on the cylinder and/or the piston is needed. This report describes the results of a research program to study the lubrication of Ti6-4 with the following chromium carbide based materials: plasma-sprayed PS212 coatings and sintered PM212 counterfaces. Program objectives are to achieve adherent coatings on Ti6-4 and to measure the friction and wear characteristics of the following sliding combinations under conditions simulative of the Stirling-driven space power linear alternator: Ti6-4/Ti6-4 baseline, Ti6-4/PS212 coated Ti6-4, and Ps212 coated Ti6-4/PM212

  15. AlSiTiN and AlSiCrN multilayer coatings: Effects of structure and surface composition on tribological behavior under dry and lubricated conditions

    International Nuclear Information System (INIS)

    Faga, Maria Giulia; Gautier, Giovanna; Cartasegna, Federico; Priarone, Paolo C.; Settineri, Luca

    2016-01-01

    Graphical abstract: - Highlights: • The demand for high performance nanostructured coatings has been increasing. • AlSiTiN and AlSiCrN nanocomposite coatings were deposited by PVD technique. • Coatings were analyzed in terms of structure, hardness and adhesion. • Tribological properties under dry and lubricated conditions were studied. • The effects of surface and bulk properties on friction evolution were assessed. - Abstract: Nanocomposite coatings have been widely studied over the last years because of their high potential in several applications. The increased interest for these coatings prompted the authors to study the tribological properties of two nanocomposites under dry and lubricated conditions (applying typical MQL media), in order to assess the influence of the surface and bulk properties on friction evolution. To this purpose, multilayer and nanocomposite AlSiTiN and AlSiCrN coatings were deposited onto tungsten carbide-cobalt (WC-Co) samples. Uncoated WC-Co materials were used as reference. Coatings were analyzed in terms of hardness and adhesion. The structure of the samples was assessed by X-ray diffraction (XRD), while the surface composition was studied by XPS analysis. Friction tests were carried out under both dry and lubricated conditions using an inox ball as counterpart. Both coatings showed high hardness and good adhesion to the substrate. As far as the friction properties are concerned, in dry conditions the surface properties affect the sliding contact at the early beginning, while bulk structure and tribolayer formation determine the main behavior. Only AlSiTiN coating shows a low and stable coefficient of friction (COF) under dry condition, while the use of MQL media results in a rapid stabilization of the COF for all the materials.

  16. DURABILITY AND TRIBOLOGICAL PROPERTIES OF THERMALLY SPRAYED WC CERMET COATING IN LUBRICATED ROLLING WITH SLIDING CONTACT

    Directory of Open Access Journals (Sweden)

    Mohammad Ali

    2010-09-01

    Full Text Available Durability and tribological properties of thermally sprayed WC-Cr-Ni cermet coating were investigated experimentally in lubricated rolling with sliding contact conditions. By means of the high energy type flame spraying (Hi-HVOF method, the coating was formed onto the axially ground and circumferentially ground roller specimens made of a thermally refined carbon steel. In the experiments, the WC cermet coated steel roller was mated with the carburized hardened steel roller without coating in line contact condition. The coated roller was mated with the smooth non-coated roller under a contact pressure of 1.0 or 1.2 GPa, and it was mated with the rough non-coated roller under a contact pressure of 0.6 or 0.8 GPa. As a result, it was found that in general, the coating on the circumferentially ground substrate shows a lower durability compared with that on the axially ground substrate and this difference appears more distinctly for the higher contact pressure for both smooth mating surface and rough mating surface. It was also found that there are significant differences in the tribological properties of WC cermet coating depending on the contact pressure. In addition, depending on the smooth or rough mating surface, remarkable differences in the tribological properties were found.

  17. 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.

  18. Pulse electrodeposition of self-lubricating Ni–W/PTFE nanocomposite coatings on mild steel surface

    Energy Technology Data Exchange (ETDEWEB)

    Sangeetha, S. [Advanced Nanocomposite Coatings Laboratory, Department of Industrial Chemistry, Alagappa University, Karaikudi 630 003 (India); Kalaignan, G. Paruthimal, E-mail: pkalaignan@yahoo.com [Advanced Nanocomposite Coatings Laboratory, Department of Industrial Chemistry, Alagappa University, Karaikudi 630 003 (India); Anthuvan, J. Tennis [M. Kumarasamy College of Engineering, Karur, Tamil Nadu (India)

    2015-12-30

    Graphical abstract: - Highlights: • PTFE polymer inclusion on Ni–W alloy matrix was electrodeposited by pulse current method. • Tribological properties and electrochemical characterizations of the nanocomposite coatings were analyzed. • The hydrophobic behaviour of Ni–W/PTFE nanocomposite coating was measured. • Ni–W/PTFE nanocomposite coatings have showed superior tribological properties and corrosion resistance relative to that of the Ni–W alloy matrix. - Abstract: Ni–W/PTFE nanocomposite coatings with various contents of PTFE (polytetafluoroethylene) particles were prepared by pulse current (PC) electrodeposition from the Ni–W plating bath containing self lubricant PTFE particles to be co-deposited. Co-deposited PTFE particulates were uniformly distributed in the Ni–W alloy matrix. The coatings were characterized by Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Analysis (EDAX), X-ray Diffractometry (XRD) and Vicker's micro hardness tester. Tafel Polarization and electrochemical Impedance methods were used to evaluate the corrosion resistance behaviour of the nanocomposite coatings in 3.5% NaCl solution. It was found that, the Ni–W/PTFE nanocomposite coating has better corrosion resistance than the Ni–W alloy coating. Surface roughness and friction coefficient of the coated samples were assessed by Mitutoyo Surftest SJ-310 (ISO1997) and Scratch tester TR-101-M4 respectively. The contact angle (CA) of a water droplet on the surface of nanocomposite coating was measured by Optical Contact Goniometry (OCA 35). These results indicated that, the addition of PTFE in the Ni–W alloy matrix has resulted moderate microhardness, smooth surface, less friction coefficient, excellent water repellency and enhanced corrosion resistance of the nanocomposite coatings.

  19. 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

  20. Tribological properties of adaptive phosphate composite coatings with addition of silver and molybdenum disulfide

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Cancan [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou (China); University of Chinese Academy of Sciences, Beijing (China); Chen, Lei, E-mail: chenlei@lzb.ac.cn [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou (China); Zhou, Jiansong, E-mail: jszhou@licp.cas.cn [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou (China); Zhou, Huidi; Chen, Jianmin [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou (China)

    2014-05-01

    Highlights: • A new kind of adaptive coatings was fabricated using relatively simple spraying techniques. • The tribological properties of Ag/MoS{sub 2} phosphate composite coatings were investigated at the temperature from 20 °C to 700 °C. • The composition and wear mechanisms of Ag/MoS{sub 2} phosphate composite coatings were also discussed. • The Ag/MoS{sub 2} phosphate composite coatings have self-repairing capability in the rubbing process at 700 °C. - Abstract: Adaptive phosphate composite coatings with addition of solid lubricants of molybdenum disulfide (MoS{sub 2}) and silver (Ag) using aluminum chromium phosphate as the binder were fabricated on high-temperature steel. The tribological properties of phosphate composite coatings were evaluated from room temperature (RT) to 700 °C. The phase composition and microstructure were investigated according to the characterization by power X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscopy (SEM). The results show that the composite coating with the Ag/MoS{sub 2} mass ratio of 2:1 exhibits the stable and low friction coefficients from RT to 700 °C and relative low wear rates at all testing temperatures. The tribo-chemical reaction between Ag and MoS{sub 2} occurred in the rubbing process to form silver molybdates compounds lubricating film. The temperature-adaptive tribological properties were attributed to the formation of lubricating films composed of lubricants silver, MoS{sub 2} and silver molybdates phases on the worn surfaces of the composites coatings in a wide-temperature range.

  1. Laser cladding of wear resistant metal matrix composite coatings

    International Nuclear Information System (INIS)

    Yakovlev, A.; Bertrand, Ph.; Smurov, I.

    2004-01-01

    A number of coatings with wear-resistant properties as well as with a low friction coefficient are produced by laser cladding. The structure of these coatings is determined by required performance and realized as metal matrix composite (MMC), where solid lubricant serves as a ductile matrix (e.g. CuSn), reinforced by appropriate ceramic phase (e.g. WC/Co). One of the engineered coating with functionally graded material (FGM) structure has a dry friction coefficient 0.12. Coatings were produced by coaxial injection of powder blend into the zone of laser beam action. Metallographic and tribological examinations were carried out confirming the advanced performance of engineered coatings

  2. Tribological performance of hard carbon coatings on 440C bearing steel

    Energy Technology Data Exchange (ETDEWEB)

    Kustas, F M; Misra, M S; Shepard, D F; Froechtenigt, J F [Martin Marietta Astronautics Group, Denver, CO (United States)

    1991-11-01

    Hard carbon coatings such as amorphous carbon, diamond and diamond-like carbon have received considerable attention for tribological applications owing to their high hardness, high modulus and desirable surface properties. Unfortunately, most of the deposition techniques induce high substrate temperatures that would temper traditional bearing steels and reduce the substrate load-carrying capability. Therefore, to effectively use these desirable coatings, a lower temperature deposition technique is required. Ion beam deposition can provide essentially ambient temperature conditions, accurate control of process parameters and good coating-substrate adhesion. To use these attributes, a test program was initiated to deposit mass-analyzed, high purity C{sup +} and CH{sub 4}{sup +} ions on molybdenum and 440C bearing steel for subsequent characterization by Raman spectroscopy and friction-wear tests. Results for a coating deposited from a carbon monoxide source showed an amorphous carbon-microcrystalline graphtie structure which exhibited very high microhardness and a three fold reduction in coefficient of friction for unlubricated tests compared to untreated 440C steel. In addition, incrementally increasing the applied load (by up to a factor of 5) resulted in progressively lower coefficients of friction, which conforms to solid lubrication theory. End-of-travel wear debris and some limited coating delamination were observed within thinner areas of the coating. Therefore an amorphous carbon-graphite coating applied to 440C steel at ambient temperature exhibits solid lubricating film characteristics with high load-carrying capability. (orig.).

  3. 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

  4. 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.

  5. 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...

  6. 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.

  7. Effect of short-term exposure to two hydrophilic-coated and one gel pre-lubricated urinary catheters on sperm vitality, motility and kinematics in vitro.

    Science.gov (United States)

    Auger, J; Rihaoui, R; François, N; Eustache, F

    2007-06-01

    This study aimed to determine the in vitro effect of a short-term exposure to two hydrophilic-coated and one gel pre-lubricated urinary catheters on human sperm quality. Semen samples of various qualities were coincubated with each catheter for 5 min at 37 degrees C. The percentages of live and motile sperm with their kinematic characteristics were blindly assessed in control and treated samples at the end of the coincubation and 10 and 55 min later. The three catheters had no effect on sperm vitality. Similarly, the lubricated catheter and one hydrophilic-coated catheter negligibly modulated sperm motility. In contrast, the other hydrophilic-coated catheter tested had a significant negative effect on sperm movement. Further studies are warranted, the issue being especially relevant to the collection of spermatozoa in spinal cord diseased patients catheterizing themselves several times a day. In this population, compounds releasing from the catheter and accumulating in the urethra could be an additional factor contributing to the poor sperm quality.

  8. Effects of texture diameter and depth on the tribological performance of DLC coating under lubricated sliding condition

    Science.gov (United States)

    Arslan, A.; Masjuki, H. H.; Varman, M.; Kalam, M. A.; Quazi, M. M.; Al Mahmud, K. A. H.; Gulzar, M.; Habibullah, M.

    2015-11-01

    In this study, the effect of surface texturing parameters on the tribological performance of amorphous hydrogenated diamond-like carbon (DLC) under oil lubrication has been investigated. Micro dimples were created on a substrate by using a picosecond laser. After surface texturing was performed, amorphous hydrogenated diamond-like carbon (DLC) coating was deposited through magnetron sputtering. Dimple diameter varied from 50 μm to 300 μm, and dimple depth varied from 6 μm to 30 μm. Results show that at respective dimple diameter and depth of 100 μm and 6 μm, surface texturing improved the tribological performance of the amorphous hydrogenated DLC coating. Whereas, at a higher dimple diameter of 300 μm and dimple depth of 30 μm, the tribological performance of textured amorphous hydrogenated DLC was worse than that of un-textured amorphous hydrogenated DLC. The performance enhancement in the case of dimple diameter and depth of 100 μm and 6 μm can be due to micro textures, which can serve as a lubricant reservoir at the interface during sliding and remove wear particles from the contact. However, this beneficial mechanism could be obtained at an optimum texture diameter and depth.

  9. 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....

  10. Analysis of Minimum Quantity Lubrication (MQL for Different Coating Tools during Turning of TC11 Titanium Alloy

    Directory of Open Access Journals (Sweden)

    Sheng Qin

    2016-09-01

    Full Text Available The tool coating and cooling strategy are two key factors when machining difficult-to-cut materials such as titanium alloy. In this paper, diamond coating was deposited on a commercial carbide insert as an attempt to increase the machinability of TC11 alloy during the turning process. An uncoated carbide insert and a commercial Al2O3/TiAlN-coated tool were also tested as a comparison. Furthermore, MQL was applied to improve the cutting condition. Cutting performances were analyzed by cutting force, cutting temperate and surface roughness measurements. Tool wears and tool lives were evaluated to find a good matchup between the tool coating and cooling strategy. According to the results, using MQL can slightly reduce the cutting force. By applying MQL, cutting temperatures and tool wears were reduced by a great amount. Besides, MQL can affect the tool wear mechanism and tool failure modes. The tool life of an Al2O3/TiAlN-coated tool can be prolonged by 88.4% under the MQL condition. Diamond-coated tools can obtain a good surface finish when cutting parameters and lubrication strategies are properly chosen.

  11. 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...

  12. 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.

  13. 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.

  14. 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.

  15. A study of DLC coatings for ironing of stainless steel

    Science.gov (United States)

    Sulaiman, M. H.; Christiansen, P.; Bay, N.

    2017-09-01

    Stamping of sheet metal components without lubrication or using minimum amount of hazard free lubricant is a possible solution to diminish health hazards to personnel and environmental impact and to reduce production costs. This paper studies the application of diamond-like coating (DLC) under severe lubrication conditions by adopting strip reduction testing to replicate industrial ironing production of deep drawn, stainless steel cans. Three DLC coatings are investigated; multi-layer, double layer and single layer. Experiments revealed that the double layer coating worked successful, i.e. with no sign of galling using no lubrication even at elevated tool temperature, while the other two coatings peeled off and resulted in severe galling unless lubrication was applied.

  16. CVD Diamond, DLC, and c-BN Coatings for Solid Film Lubrication

    Science.gov (United States)

    Miyoshi, Kazuhisa

    1998-01-01

    When the main criteria for judging coating performance were coefficient of friction and wear rate, which had to be less than 0.1 and 10(exp -6) mm(exp 3)/N-m, respectively, carbon- and nitrogen-ion-implanted, fine-grain CVD diamond and DLC ion beam deposited on fine-grain CVD diamond met the requirements regardless of environment (vacuum, nitrogen, and air).

  17. 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.

  18. Tribological study of novel metal-doped carbon-based coatings with enhanced thermal stability

    Science.gov (United States)

    Mandal, Paranjayee

    Low friction and high temperature wear resistant PVD coatings are in high demand for use on engine components, which operate in extreme environment. Diamond-like-carbon (DLC) coatings are extensively used for this purpose due to their excellent tribological properties. However, DLC degrades at high temperature and pressure conditions leading to significant increase in friction and wear rate even in the presence of lubricant. To withstand high working temperature and simultaneously maintain improved tribological properties in lubricated condition at ambient and at high temperature, both the transitional metals Mo and W are simultaneously introduced in a carbon-based coating (Mo-W-C) for the first time utilising the benefits of smart material combination and High Power Impulse Magnetron Sputtering (HIPIMS).This research includes development of Mo-W-C coating and investigation of thermal stability and tribological properties at ambient and high temperatures. The as-deposited Mo-W-C coating contains nanocrystalline almost X-ray amorphous structure and show dense microstructure, good adhesion with substrate (Lc -80 N) and high hardness (-17 GPa). During boundary lubricated sliding (commercially available engine oil without friction modifier used as lubricant) at ambient temperature, Mo-W-C coating outperforms commercially available state-of-the-art DLC coatings by providing significantly low friction (u- 0.03 - 0.05) and excellent wear resistance (no measurable wear). When lubricated sliding tests are carried out at 200°C, Mo-W-C coating provides low friction similar to ambient temperature, whereas degradation of DLC coating properties fails to maintain low friction coefficient.A range of surface analyses techniques reveal "in-situ" formation of solid lubricants (WS2 and M0S2) at the tribo-contacts due to tribochemically reactive wear mechanism at ambient and high temperature. Mo-W-C coating reacts with EP additives present in the engine oil during sliding to form WS2

  19. 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).

  20. 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

  1. Effect of mating materials on wear properties of amorphous hydrogenated carbon (a-C:H coating and tetrahedral amorphous carbon (ta-C coating in base oil boundary lubrication condition

    Directory of Open Access Journals (Sweden)

    Xiang Li

    2017-12-01

    Full Text Available In this study, wear behavior of amorphous hydrogenated carbon (a-C:H coating and tetrahedral amorphous carbon (ta-C coating when sliding against various mating materials in base oil boundary lubrication condition is comparatively investigated to find out the optimal combinations of DLC/mating material and corresponding wear mechanism of both DLC coating. Tribological tests were performed in a cylinder-on-disc tribometer, Field Emission Scanning Electron Microscopy, Raman spectroscopy is used for characterization of ta-C and a-C:H worn surface. The results show that the specific wear rate of ta-C coating increases along with the hardness and roughness of mating material increases, while the specific wear rate of a-C:H coating increases together with an increment in the ID/IG ratio. It is concluded that for ta-C coating, local stress concentration-induced microfracture is the main wear mechanism in relative high wear scenario, along with minor graphitization-induced wear which prevails in low wear scenario. On the other hand, a-C:H coating showed that simultaneous generation and removal of the graphitized layer on the contact surface is the predominant wear mechanism.

  2. Porous Organic Nanolayers for Coating of Solid-state Devices

    Science.gov (United States)

    2011-01-01

    Background Highly hydrophobic surfaces can have very low surface energy and such low surface energy biological interfaces can be obtained using fluorinated coatings on surfaces. Deposition of biocompatible organic films on solid-state surfaces is attained with techniques like plasma polymerization, biomineralization and chemical vapor deposition. All these require special equipment or harsh chemicals. This paper presents a simple vapor-phase approach to directly coat solid-state surfaces with biocompatible films without any harsh chemical or plasma treatment. Hydrophilic and hydrophobic monomers were used for reaction and deposition of nanolayer films. The monomers were characterized and showed a very consistent coating of 3D micropore structures. Results The coating showed nano-textured surface morphology which can aid cell growth and provide rich molecular functionalization. The surface properties of the obtained film were regulated by varying monomer concentrations, reaction time and the vacuum pressure in a simple reaction chamber. Films were characterized by contact angle analysis for surface energy and with profilometer to measure the thickness. Fourier Transform Infrared Spectroscopy (FTIR) analysis revealed the chemical composition of the coated films. Variations in the FTIR results with respect to different concentrations of monomers showed the chemical composition of the resulting films. Conclusion The presented approach of vapor-phase coating of solid-state structures is important and applicable in many areas of bio-nano interface development. The exposure of coatings to the solutions of different pH showed the stability of the coatings in chemical surroundings. The organic nanocoating of films can be used in bio-implants and many medical devices. PMID:21569579

  3. Porous Organic Nanolayers for Coating of Solid-state Devices

    Directory of Open Access Journals (Sweden)

    Asghar Waseem

    2011-05-01

    Full Text Available Abstract Background Highly hydrophobic surfaces can have very low surface energy and such low surface energy biological interfaces can be obtained using fluorinated coatings on surfaces. Deposition of biocompatible organic films on solid-state surfaces is attained with techniques like plasma polymerization, biomineralization and chemical vapor deposition. All these require special equipment or harsh chemicals. This paper presents a simple vapor-phase approach to directly coat solid-state surfaces with biocompatible films without any harsh chemical or plasma treatment. Hydrophilic and hydrophobic monomers were used for reaction and deposition of nanolayer films. The monomers were characterized and showed a very consistent coating of 3D micropore structures. Results The coating showed nano-textured surface morphology which can aid cell growth and provide rich molecular functionalization. The surface properties of the obtained film were regulated by varying monomer concentrations, reaction time and the vacuum pressure in a simple reaction chamber. Films were characterized by contact angle analysis for surface energy and with profilometer to measure the thickness. Fourier Transform Infrared Spectroscopy (FTIR analysis revealed the chemical composition of the coated films. Variations in the FTIR results with respect to different concentrations of monomers showed the chemical composition of the resulting films. Conclusion The presented approach of vapor-phase coating of solid-state structures is important and applicable in many areas of bio-nano interface development. The exposure of coatings to the solutions of different pH showed the stability of the coatings in chemical surroundings. The organic nanocoating of films can be used in bio-implants and many medical devices.

  4. 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.

  5. 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.

  6. 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

  7. Rolling contact fatigue in a vacuum test equipment and coating analysis

    CERN Document Server

    Danyluk, Michael

    2014-01-01

    This book deals with wear and performance testing of thin solid film lubrication and hard coatings in an ultra-high vacuum (UHV), a process which enables rapid accumulation of stress cycles compared with testing in oil at atmospheric pressure. The authors' lucid and authoritative narrative broadens readers' understanding of the benefits of UHV testing: a cleaner, shorter test is achieved in high vacuum, disturbance rejection by the deposition controller may be optimized for maximum fatigue life of the coating using rolling contact fatigue testing (RCF) in a high vacuum, and RCF testing in UHV

  8. Hydrodynamic air lubricated compliant surface bearing for an automotive gas turbine engine. 2: Materials and coatings

    Science.gov (United States)

    Bhushan, B.; Ruscitto, D.; Gray, S.

    1978-01-01

    Material coatings for an air-lubricated, compliant journal bearing for an automotive gas turbine engine were exposed to service test temperatures of 540 C or 650 C for 300 hours, and to 10 temperature cycles from room temperatures to the service test temperatures. Selected coatings were then put on journal and partial-arc foils and tested in start-stop cycle tests at 14 kPa (2 psi) loading for 2000 cycles. Half of the test cycles were performed at a test chamber service temperature of 540 C (1000 F) or 650 C (1200 F); the other half were performed at room temperature. Based on test results, the following combinations and their service temperature limitations are recommended: HL-800 TM (CdO and graphite) on foil versus chrome carbide on journal up to 370 C (700 F); NASA PS 120 (Tribaloy 400, silver and CaF2 on journal versus uncoated foil up to 540 C (1000 F); and Kaman DES on journal and foil up to 640 C (1200 F). Kaman DES coating system was further tested successfully at 35 kPa (5 psi) loading for 2000 start-stop cycles.

  9. 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.

  10. Protective Coatings

    Science.gov (United States)

    1980-01-01

    General Magnaplate Corporation's pharmaceutical machine is used in the industry for high speed pressing of pills and capsules. Machine is automatic system for molding glycerine suppositories. These machines are typical of many types of drug production and packaging equipment whose metal parts are treated with space spinoff coatings that promote general machine efficiency and contribute to compliance with stringent federal sanitation codes for pharmaceutical manufacture. Collectively known as "synergistic" coatings, these dry lubricants are bonded to a variety of metals to form an extremely hard slippery surface with long lasting self lubrication. The coatings offer multiple advantages; they cannot chip, peel or be rubbed off. They protect machine parts from corrosion and wear longer, lowering maintenance cost and reduce undesired heat caused by power-robbing friction.

  11. 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

  12. 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

  13. 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.

  14. 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.

  15. Dry coating of solid dosage forms: an overview of processes and applications.

    Science.gov (United States)

    Foppoli, Anastasia Anna; Maroni, Alessandra; Cerea, Matteo; Zema, Lucia; Gazzaniga, Andrea

    2017-12-01

    Dry coating techniques enable manufacturing of coated solid dosage forms with no, or very limited, use of solvents. As a result, major drawbacks associated with both organic solvents and aqueous coating systems can be overcome, such as toxicological, environmental, and safety-related issues on the one hand as well as costly drying phases and impaired product stability on the other. The considerable advantages related to solventless coating has been prompting a strong research interest in this field of pharmaceutics. In the article, processes and applications relevant to techniques intended for dry coating are analyzed and reviewed. Based on the physical state of the coat-forming agents, liquid- and solid-based techniques are distinguished. The former include hot-melt coating and coating by photocuring, while the latter encompass press coating and powder coating. Moreover, solventless techniques, such as injection molding and three-dimensional printing by fused deposition modeling, which are not purposely conceived for coating, are also discussed in that they would open new perspectives in the manufacturing of coated-like dosage forms.

  16. Corrosion protection of steel by thin coatings of starch-oil dry lubricants

    Science.gov (United States)

    Corrosion of materials is one of the most serious and challenging problems faced worldwide by industry. Dry lubricants reduce friction between two metal surfaces. This research investigated the inhibition of corrosive behavior a dry lubricant formulation consisting of jet-cooked corn starch and soyb...

  17. Influence of zinc dialkyldithiophosphate tribofilm formation on the tribological performance of self-mated diamond-like carbon contacts under boundary lubrication

    Energy Technology Data Exchange (ETDEWEB)

    Abdullah Tasdemir, H., E-mail: habdullah46@gmail.com [Department of Mechanical Science and Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603 (Japan); Tokoroyama, Takayuki; Kousaka, Hiroyuki; Umehara, Noritsugu [Department of Mechanical Science and Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603 (Japan); Mabuchi, Yutaka [Nissan Motor Co. (Japan)

    2014-07-01

    Diamond-like carbon (DLC) coatings offer excellent mechanical and tribological properties that make them suitable protective coatings for various industrial applications. In recent years, several engine and power train components in passenger cars, which work under boundary lubricated conditions, have been coated with DLC coatings. Since conventional lubricants and lubricant additives are formulated for metal surfaces, there are still controversial questions concerning chemical reactivity between DLC surfaces and common lubricant additives owing to the chemical inertness of DLC coatings. In this work, we present the influence of zinc dialkyldithiophosphate (ZnDTP) anti-wear additives on the tribological performance of various self-mated DLC coatings under boundary lubrication conditions. The effects of hydrogen, doping elements, and surface morphology on the reactivity of DLC coatings to form a ZnDTP-derived tribofilm were investigated by atomic force microscopy, field emission scanning electron microscopy and X-ray photoelectron spectroscopy. The results confirmed that ZnDTP-derived pad-like or patchy tribofilm forms on the surfaces depending on the DLC coating. It is seen that hydrogen content and doping elements increase pad-like tribofilm formation. Doped DLC coatings are found to give better wear resistance than non-doped DLC coatings. Furthermore, the addition of ZnDTP additives to the base oil significantly improves the wear resistance of hydrogenated DLC, silicon-doped hydrogenated DLC, and chromium-doped hydrogenated DLC. Hydrogen-free tetrahedral amorphous DLC coatings provide the lowest friction coefficient both in PAO (poly-alpha-olefin) and PAO + ZnDTP oils. - Highlights: • Zinc dialkyldithiophosphate (DTP) tribofilm formation on various DLC surfaces was evidenced. • Pad-like tribofilm was found on a-C:H, a-C, Si-DLC and Cr-DLC. • Pad-like tribofilm on DLC surfaces greatly increased the wear resistance. • Hydrogenated and doped DLC coatings are

  18. Influence of zinc dialkyldithiophosphate tribofilm formation on the tribological performance of self-mated diamond-like carbon contacts under boundary lubrication

    International Nuclear Information System (INIS)

    Abdullah Tasdemir, H.; Tokoroyama, Takayuki; Kousaka, Hiroyuki; Umehara, Noritsugu; Mabuchi, Yutaka

    2014-01-01

    Diamond-like carbon (DLC) coatings offer excellent mechanical and tribological properties that make them suitable protective coatings for various industrial applications. In recent years, several engine and power train components in passenger cars, which work under boundary lubricated conditions, have been coated with DLC coatings. Since conventional lubricants and lubricant additives are formulated for metal surfaces, there are still controversial questions concerning chemical reactivity between DLC surfaces and common lubricant additives owing to the chemical inertness of DLC coatings. In this work, we present the influence of zinc dialkyldithiophosphate (ZnDTP) anti-wear additives on the tribological performance of various self-mated DLC coatings under boundary lubrication conditions. The effects of hydrogen, doping elements, and surface morphology on the reactivity of DLC coatings to form a ZnDTP-derived tribofilm were investigated by atomic force microscopy, field emission scanning electron microscopy and X-ray photoelectron spectroscopy. The results confirmed that ZnDTP-derived pad-like or patchy tribofilm forms on the surfaces depending on the DLC coating. It is seen that hydrogen content and doping elements increase pad-like tribofilm formation. Doped DLC coatings are found to give better wear resistance than non-doped DLC coatings. Furthermore, the addition of ZnDTP additives to the base oil significantly improves the wear resistance of hydrogenated DLC, silicon-doped hydrogenated DLC, and chromium-doped hydrogenated DLC. Hydrogen-free tetrahedral amorphous DLC coatings provide the lowest friction coefficient both in PAO (poly-alpha-olefin) and PAO + ZnDTP oils. - Highlights: • Zinc dialkyldithiophosphate (DTP) tribofilm formation on various DLC surfaces was evidenced. • Pad-like tribofilm was found on a-C:H, a-C, Si-DLC and Cr-DLC. • Pad-like tribofilm on DLC surfaces greatly increased the wear resistance. • Hydrogenated and doped DLC coatings are

  19. 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...

  20. 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

  1. A comparison of the tribological behaviour of steel/steel, steel/DLC and DLC/DLC contact when lubricated with mineral and biodegradable oils

    OpenAIRE

    Kalin, Mitjan; Vižintin, Jože

    2015-01-01

    Diamond-like carbon (DLC) coatings, which can nowadays be applied to many highly loaded mechanical components, sometimes need to operate under lubricated conditions. It is reasonable to expect that in steel/DLC contacts, at least the steel counter body will behave according to conventional lubrication mechanisms and will interact with lubricants and additives in the contact. However, in DLC/DLC contacts, such mechanisms are still unclear. For example, the "inertness" of DLC coatings raises se...

  2. 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...

  3. 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.

  4. Influence of the coating process on the tribological conditions during cold forging with a MoS2 based lubricant

    Science.gov (United States)

    Lorenz, Robby; Hagenah, Hinnerk; Merklein, Marion

    2018-05-01

    Cold forging processes such as forward rod extrusion can be used to produce high quality components like connection rods, shafts and gears. The main advantages of these extruded components are sufficient surface quality, work hardening, compressive residual stresses and fatigue strength. Since one technical disadvantage of extruded components lies in the achievable tolerance classes, the improvement of these should be of crucial importance. For instance, the attainable workpiece accuracy and component quality can be influenced by adapting the tribological system in such a way that the resulting friction is specifically controlled in order to improve component forming. Lubricant modification is one practical way of adapting the tribological system to the requirements of the forming process. An industrial established and highly efficient lubricant system is the application of a zinc-phosphate conversion layer with a molybdenum disulfide-based lubricant. While offering many advantages, its tribological conditions seem to depend strongly on the layer weight and the application strategy. These parameters and the respective interdependencies have not been sufficiently investigated yet. In order to examine this, the tribological conditions depending on the layer weight are analyzed in greater detail using the Ring-Compression-Test (RCT). This tribometer provides a comparative representation of the forming conditions during cold forging. Furthermore, a potential dependency between the tribological conditions and two different coating techniques is analyzed. The latter are represented by the industrial standards dipping and dip-drumming.

  5. 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....

  6. Evaluation of Protective Ability of High Solid Novolac Clear Coatings Through Electrochemical Techniques

    International Nuclear Information System (INIS)

    Ramesh, D.; Shakkthivel, P.; Manickam, A. Susai; Kalpana, A.; Vasudevan, T.

    2006-01-01

    Solvent free high solid coatings are increasingly used as they posses number of advantages such as, lower cost per unit film thickness, better performance and eco-friendliness. In the present study polymeric film-forming materials such as aniline-novolac (ANS), cresol-novolac (CNS) and acrylic copolymer blended cresol-novolac (ACNS) coating materials have been prepared. The corrosion resistance properties of the prepared high solid coating materials have been evaluated through potential-time, potentiodynamic polarization and electrochemical impedance studies (EIS). Among the three coating systems, cresol-novolac polymer coated substrates offer better corrosion resistance property and the order of the performance was found as CNS > ACNS > ANS. We can recommend these systems for use in automobile applications

  7. Industrial tribology tribosystems, friction, wear and surface engineering, lubrication

    CERN Document Server

    Mang, Theo; Bartels, Thorsten

    2010-01-01

    Integrating very interesting results from the most important R & D project ever made in Germany, this book offers a basic understanding of tribological systems and the latest developments in reduction of wear and energy consumption by tribological measures. This ready reference and handbook provides an analysis of the most important tribosystems using modern test equipment in laboratories and test fields, the latest results in material selection and wear protection by special coatings and surface engineering, as well as with lubrication and lubricants.This result is a quick introductio

  8. Shear thinning behavior of monolayer liquid lubricant films measured by fiber wobbling method

    International Nuclear Information System (INIS)

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

    2010-01-01

    It is essential to clarify mechanical properties of monolayer lubricant films coated on magnetic disks under shearing motion for designing future hard disk drives with ultra-low flying height. Many of previous researchers reported that strong shear rate dependence of viscoelasticity was one of the typical phenomena observed with molecularly thin liquid films. However, it has not been clarified whether or not perfluoropolyether (PFPE) lubricant films, which are used for the head-disk interface (HDI) lubrication, show shear thinning behavior under actual HDI conditions. In this study, we used the fiber wobbling method that can achieve both highly-sensitive shear force measurement and precise gap control and measured shear rate dependence of viscoelastic properties of monolayer PFPE films coated on the magnetic disk. Our experimental results showed that shear thinning does occur at high shear rate ranged from 10 2 to 10 6 s -1 .

  9. 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

  10. 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

  11. 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.

  12. 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)

  13. 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.

  14. 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.

  15. 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...

  16. Dry rotary swaging with structured and coated tools

    Science.gov (United States)

    Herrmann, Marius; Schenck, Christian; Kuhfuss, Bernd

    2018-05-01

    Rotary swaging is a cold bulk forming process for manufacturing of complex bar and tube profiles like axles and gear shafts in the automotive industry. Conventional rotary swaging is carried out under intense use of lubricant usually based on mineral oil. Besides lubrication the lubricant fulfills necessary functions like lubrication, flushing and cooling, but generates costs for recycling, replacement and cleaning of the workpieces. Hence, the development of a dry process design is highly desirable, both under economic and ecological points of view. Therefore, it is necessary to substitute the functions of the lubricant. This was realized by the combination of newly developed a-C:H:W coating systems on the tools to minimize the friction and to avoid adhesion effects. With the application of a deterministic structure in the forging zone of the tools the friction conditions are modified to control the axial process forces. In this study infeed rotary swaging with functionalized tools was experimentally investigated. Therefore, steel and aluminum tubes were formed with and without lubricant. Different structures which were coated and uncoated were implemented in the reduction zone of the tools. The antagonistic effects of coating and structuring were characterized by measuring the axial process force and the produced workpiece quality in terms of roundness and surface roughness. Thus, the presented results allow for further developments towards a dry rotary swaging process.

  17. 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

  18. Application of hard coatings for blanking and piercing tools

    DEFF Research Database (Denmark)

    Podgornik, B.; Zajec, B.; Bay, Niels

    2011-01-01

    The aim of the present investigation was to examine the possibility of reducing lubrication and replacing expensive tungsten carbide material in blanking/piercing through introduction of hard tool coatings. Results show that hard PVD coatings can be successfully used in blanking/piercing...... critical value under dry friction conditions and leads to tool failure. Therefore, at present oxidation and temperature resistant hard coatings can give improved wear resistance of stamping tools, but elimination of lubricants in blanking and piercing processes is still not feasible....

  19. 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.

  20. 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.

  1. Electrostatic powder coatings of pristine graphene: A new approach for coating of granular and fibril substrates

    Science.gov (United States)

    Nine, Md J.; Kabiri, Shervin; Tung, Tran Thanh; Tran, Diana N. H.; Losic, Dusan

    2018-05-01

    The use of pristine graphene (pG) based on solution processed coating technologies is often limited by their poor dispersibility in water and organic solvents which prevents to achieve the best performing properties of pG in coating applications. To address these limitations, we developed a dispersant-free coating approach of pG based on their intrinsic solid-lubricity and interlayer electrostatic interactions. The "rotating drum" method was established to provide suitable conditions for electrostatic deposition of pG-powder which is demonstrated on two model substrates with granular and fibril morphologies (urea and acrylic fibers) to improve their physical and electrical properties. The results showed that the pG coating enables to minimize moisture induced caking tendency of commercial urea prills at a relative humidity (RH) of 85% (higher than critical humidity) exhibiting greater moisture rejection ability (∼2 times higher than uncoated urea) and to improve their anti-abrasive properties. The pG-powder coating applied on nonconductive acrylic fibers provides a stable conductive layer (∼0.8 ± 0.1 kΩ/sq) which made them suitable for using in wearable electronics, sensors and electromagnetic interference (EMI) shielding. The developed coating method for pG-powder based on "rotating drum" is generic, simple, eco-friendly, low-cost, and scalable for broad range of coating applications.

  2. Room-temperature solid phase ionic liquid (RTSPIL) coated Ω-transaminases: Development and application in organic solvents

    DEFF Research Database (Denmark)

    Grabner, B.; Nazario, M. A.; Gundersen, M. T.

    2018-01-01

    ω-Transaminases ATA-40, ATA-47 and ATA-82P were coated with room-temperature solid phase ionic liquids (RTSPILs) by means of three methods, melt coating, precipitation coating, and co‐lyophilization, and showed increased stability in all of the five tested organic solvents. Co‐lyophilization and ......ω-Transaminases ATA-40, ATA-47 and ATA-82P were coated with room-temperature solid phase ionic liquids (RTSPILs) by means of three methods, melt coating, precipitation coating, and co‐lyophilization, and showed increased stability in all of the five tested organic solvents. Co...

  3. 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)

  4. 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.

  5. Zwitterionic Nanofibers of Super-Glue for Transparent and Biocompatible Multi-Purpose Coatings

    Science.gov (United States)

    Mele, Elisa; Heredia-Guerrero, José A.; Bayer, Ilker S.; Ciofani, Gianni; Genchi, Giada G.; Ceseracciu, Luca; Davis, Alexander; Papadopoulou, Evie L.; Barthel, Markus J.; Marini, Lara; Ruffilli, Roberta; Athanassiou, Athanassia

    2015-09-01

    Here we show that macrozwitterions of poly(ethyl 2-cyanoacrylate), commonly called Super Glue, can easily assemble into long and well defined fibers by electrospinning. The resulting fibrous networks are thermally treated on glass in order to create transparent coatings whose superficial morphology recalls the organization of the initial electrospun mats. These textured coatings are characterized by low liquid adhesion and anti-staining performance. Furthermore, the low friction coefficient and excellent scratch resistance make them attractive as solid lubricants. The inherent texture of the coatings positively affects their biocompatibility. In fact, they are able to promote the proliferation and differentiation of myoblast stem cells. Optically-transparent and biocompatible coatings that simultaneously possess characteristics of low water contact angle hysteresis, low friction and mechanical robustness can find application in a wide range of technological sectors, from the construction and automotive industries to electronic and biomedical devices.

  6. CrN-based wear resistant hard coatings for machining and forming tools

    Energy Technology Data Exchange (ETDEWEB)

    Yang, S; Cooke, K E; Teer, D G [Teer Coatings Ltd, West Stone House, Berry Hill Industrial Estate, Droitwich, Worcestershire WR9 9AS (United Kingdom); Li, X [School of Metallurgy and Materials, University of Birmingham, Birmingham B15 2TT (United Kingdom); McIntosh, F [Rolls-Royce plc, Inchinnan, Renfrewshire PA4 9AF, Scotland (United Kingdom)

    2009-05-21

    Highly wear resistant multicomponent or multilayer hard coatings, based on CrN but incorporating other metals, have been developed using closed field unbalanced magnetron sputter ion plating technology. They are exploited in coated machining and forming tools cutting and forming of a wide range of materials in various application environments. These coatings are characterized by desirable properties including good adhesion, high hardness, high toughness, high wear resistance, high thermal stability and high machining capability for steel. The coatings appear to show almost universal working characteristics under operating conditions of low and high temperature, low and high machining speed, machining of ordinary materials and difficult to machine materials, and machining under lubricated and under minimum lubricant quantity or even dry conditions. These coatings can be used for cutting and for forming tools, for conventional (macro-) machining tools as well as for micromachining tools, either as a single coating or in combination with an advanced, self-lubricating topcoat.

  7. Investigation of Wear Coefficient of Manganese Phosphate Coated Tool Steel

    Directory of Open Access Journals (Sweden)

    S. Ilaiyavel

    2013-03-01

    Full Text Available In recent years the properties of the coating in terms of wear resistance is of paramount importance in order to prevent the formation of severe damages. In this study, Wear coefficient of uncoated, Manganese Phosphate coated, Manganese Phosphate coated with oil lubricant, Heat treated Manganese Phosphate coated with oil lubricant on AISI D2 steels was investigated using Archard’s equation. The wear tests were performed in a pin on disk apparatus as per ASTM G-99 Standard. The volumetric wear loss and wear coefficient were evaluated through pin on disc test using a sliding velocity of 3.0 m/s under normal load of 40 N and controlled condition of temperature and humidity. Based on the results of the wear test, the Heat treated Manganese Phosphate with oil lubricant exhibited the lowest average wear coefficient and the lowest wear loss under 40 N load.

  8. Characterization of Lubricants on Ball Bearings by FT-IR Using an Integrating Sphere

    Science.gov (United States)

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

    2007-01-01

    Fourier Transform-Infrared reflectance microspectroscopy has been used extensively for the examination of coatings on nonplanar surfaces such as ball bearings. While this technique offers considerable advantages, practical application has many drawbacks, some of which are easily overcome by the use of integrating sphere technology. This paper describes the use of an integrating sphere for the quantification of thin layers of lubricant on the surface of ball bearings and the parameters which require optimization in order to obtain reliable data. Several applications of the technique are discussed including determination of lubricant load on 12.7 mm steel ball bearings and the examination of degraded lubricant on post mortem specimens.

  9. 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.

  10. CrCuAgN PVD nanocomposite coatings: Effects of annealing on coating morphology and nanostructure

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xingguang, E-mail: xingguangliu1@gmail.com [Department of Materials Science and Engineering, Sir Robert Hadfield Building, The University of Sheffield, Mappin Street, Sheffield, S1 3JD (United Kingdom); Iamvasant, Chanon, E-mail: ciamvasant1@sheffield.ac.uk [Department of Materials Science and Engineering, Sir Robert Hadfield Building, The University of Sheffield, Mappin Street, Sheffield, S1 3JD (United Kingdom); Liu, Chang, E-mail: chang.liu@sheffield.ac.uk [Department of Materials Science and Engineering, Sir Robert Hadfield Building, The University of Sheffield, Mappin Street, Sheffield, S1 3JD (United Kingdom); Matthews, Allan, E-mail: allan.matthews@manchester.ac.uk [Pariser Building - B24 ICAM, School of Materials, The University of Manchester, Manchester, M13 9PL (United Kingdom); Leyland, Adrian, E-mail: a.leyland@sheffield.ac.uk [Department of Materials Science and Engineering, Sir Robert Hadfield Building, The University of Sheffield, Mappin Street, Sheffield, S1 3JD (United Kingdom)

    2017-01-15

    found that, with sufficient Cu content (>12 at.%), annealing at a moderately high temperature (e.g. 500 °C) leads to transportation of both Cu and Ag (even at relatively low concentrations of Ag, ≤3 at.%) from inside the coating to the coating surface, which resulted in significant reductions in friction coefficient, by over 50% compared to that of the substrate (from 0.31 to 0.14 with a hemispherical diamond indenter, and from 0.83 to 0.40 with an alumina ball counterface, respectively). Results indicate that the addition of both Cu and Ag (in appropriate concentrations) to nitrogen-containing chromium is a viable strategy for the development of ‘self-replenishing’ silver-containing thin film architectures for temperature-dependent solid lubrication requirements or antimicrobial coating applications.

  11. 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.

  12. Optimization and characterization of adhesion properties of DLC coatings on different substrates

    International Nuclear Information System (INIS)

    Waseem, B; Alam, S; Irfan, M; Shahid, M; Soomro, B D; Hashim, S; Iqbal, R

    2014-01-01

    The Diamond Like Carbon coatings (DLC) are gaining prime importance in the field of surface engineering especially cutting tools technology. The self lubricating property of these coatings makes them unique among other coatings like TiN, TiAlN, CrN etc. Unlike other coatings, DLC coatings give better surface finish and their self lubrication reduces the wear of a part to large extent. In present work, different substrates were selected to study the wear and adhesion behavior of DLC coatings. The coating was produced by physical Vapor Deposition (PVD) technique and the adhesive properties of DLC coatings were analyzed under ambient conditions using nano Scratch testing. Scanning electron microscope (SEM) was used to observe the scratches and their mechanisms

  13. Optimization and characterization of adhesion properties of DLC coatings on different substrates

    International Nuclear Information System (INIS)

    Waseem, B.; Alam, S.; Irfan, M.; Shahid, M.; Soomro, B. D.; Hashim, S.; Iqbal, R.

    2013-01-01

    The Diamond Like Carbon coatings (DLC) are gaining prime importance in the field of surface engineering especially cutting tools technology. The self lubricating property of these coatings makes them unique among other coatings like TiN, TiAlN, CrN etc. Unlike other coatings, DLC coatings give better surface finish and their self lubrication reduces the wear of a part to large extent. In present work, different substrates were selected to study the wear and adhesion behavior of DLC coatings. The coating was produced by physical Vapor Deposition (PVD) technique and the adhesive properties of DLC coatings were analyzed under ambient conditions using nano Scratch testing. Scanning electron microscope (SEM) was used to observe the scratches and their mechanisms. (author)

  14. Lubricating coating prepared by PIIID on a forming tool

    International Nuclear Information System (INIS)

    Martinatti, J F; Durrant, S F; Cruz, N C; Rangel, E C; Santos, L V

    2012-01-01

    In this work, the performance of a-C:H films produced by the hybrid Plasma Immersion Ion Implantation and Deposition technique as lubricating layers for a steel forming tool has been investigated. Hardened steel (AISI M2, 64 HRC) plates coated with a commercial TiN layer were used as substrates and the films were deposited in a vacuum chamber fitted with two parallel-plate electrodes. The discharges were generated in atmospheres composed of 91% C 2 H 2 and 9% Ar by the application of radiofrequency power (13.56 MHz, 100 W) to the upper electrode while the lower one, also used as the sample holder, was biased with high voltage negative pulses (3.6 kV, 30 μs, 300 Hz). A deposition time of 840 s was used. The effects of the gas pressure, p, on thickness, molecular structure, wettability, surface morphology and topography, hardness and friction coefficient of the films were investigated. Film thickness increased from 0.3 to 0.5 μm when p was increased from 2.7 to 16.5 Pa. Generally, the films were slightly hydrophilic, with contact angles of around 84°, and the deposition decreased the roughness of the steel. A polymer-like structure was detected in high pressure depositions and an amorphous carbon structure derived from the low pressure procedures. Hardness decreased from 8.2 to 7.0 GPa with increasing p. Improvement in tribological performance was indicated by the fall in the friction coefficient from 0.5 to 0.2 as the deposition pressure was reduced. Operating at the latter value (of μ) would lead to a significant reduction in wear and hence to significant economy in diverse industrial applications.

  15. 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...

  16. 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.

  17. Particle Engineering Via Mechanical Dry Coating in the Design of Pharmaceutical Solid Dosage Forms.

    Science.gov (United States)

    Qu, Li; Morton, David A V; Zhou, Qi Tony

    2015-01-01

    Cohesive powders are problematic in the manufacturing of pharmaceutical solid dosage forms because they exhibit poor flowability, fluidization and aerosolization. These undesirable bulk properties of cohesive powders represent a fundamental challenge in the design of efficient pharmaceutical manufacturing processes. Recently, mechanical dry coating has attracted increasing attention as it can improve the bulk properties of cohesive powders in a cheaper, simpler, safer and more environment-friendly way than the existing solvent-based counterparts. In this review, mechanical dry coating techniques are outlined and their potential applications in formulation and manufacturing of pharmaceutical solid dosage forms are discussed. Reported data from the literature have shown that mechanical dry coating holds promise for the design of superior pharmaceutical solid formulations or manufacturing processes by engineering the interfaces of cohesive powders in an efficient and economical way.

  18. 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.

  19. 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.

  20. 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

  1. Surface protection of austenitic steels by carbon nanotube coatings

    Science.gov (United States)

    MacLucas, T.; Schütz, S.; Suarez, S.; Mücklich, F.

    2018-03-01

    In the present study, surface protection properties of multiwall carbon nanotubes (CNTs) deposited on polished austenitic stainless steel are evaluated. Electrophoretic deposition is used as a coating technique. Contact angle measurements reveal hydrophilic as well as hydrophobic wetting characteristics of the carbon nanotube coating depending on the additive used for the deposition. Tribological properties of carbon nanotube coatings on steel substrate are determined with a ball-on-disc tribometer. Effective lubrication can be achieved by adding magnesium nitrate as an additive due to the formation of a holding layer detaining CNTs in the contact area. Furthermore, wear track analysis reveals minimal wear on the coated substrate as well as carbon residues providing lubrication. Energy dispersive x-ray spectroscopy is used to qualitatively analyse the elemental composition of the coating and the underlying substrate. The results explain the observed wetting characteristics of each coating. Finally, merely minimal oxidation is detected on the CNT-coated substrate as opposed to the uncoated sample.

  2. 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.

  3. Development and synthesis nanocompositions DLC coatings with orientation effect

    International Nuclear Information System (INIS)

    Levchenko, V.A.; Novoselova, N.V.; Matveenko, V.N.

    2008-01-01

    On the basis of volume modelling and a detailed experimental research of physical and chemical properties nanocompositions DLC with one-dimensional highly orientationally the carbon structure on interphase border of section with lubricant as models tribological knot, proves typical models of synthesis new nanocompositions the DLC possessing high tribological properties (by high wear resistance, low of a friction, etc.). The influence mechanism orientation properties of a surface of the synthesized coatings on molecular in a boundary lubricant layer is investigated. On basis tribological experimental batch tests nanocompositions the carbon coatings possessing orientation effect, the synthesis mechanism highly orientationally DLC coatings with optimum tribological properties is developed.

  4. Experimental Analysis of Damping and Tribological Characteristics of Nano-CuO Particle Mixed Lubricant in Ball Bearings

    Science.gov (United States)

    Prakash, E.; Sivakumar, K.

    2015-12-01

    Experimental analysis of damping capacity and tribological characteristics of nano CuO added Servosystem 68 lubricant is attempted. CuO nano particles were synthesized by aqueous precipitation method and characterized. Prior to dispersion into lubricant, CuO nano particles were coated with 0.2 wt.% surfactant (Span-80) to stabilize the nano fluid. Tribological characteristics of particle added lubricant were tested in ASTM D 4172 four ball wear tester. Scanning electron microscopy test results of worn surfaces of nano CuO particle added lubricant were smoother than base lubricant. The particle added lubricant was applied in a new ball bearing and three defected ball bearings. When particle added lubricant was used, the ball defected bearing's vibration amplitude was reduced by 21.94% whereas it was 16.46% for new bearing and was ≤ 11% for other defected bearings. The formation of protection film of CuO over ball surface and regime of full film lubrication near the ball zone were observed to be reason for improved damping of vibrations.

  5. Oral coatings: a study on the formation, clearance and perception

    NARCIS (Netherlands)

    Camacho, S.

    2015-01-01

    Oral coatings are residues of food and beverages that coat the oral mucosa after consumption. Several studies have reported on the lubrication properties in mouth, and the after-feel and after-taste impact of oral coatings. Further, oral coatings have been suggested to influence subsequent taste

  6. 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...

  7. Friction of self-lubricating surfaces by ion beam techniques. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharya, R.S.; Rai, A.K.

    1992-05-01

    UES, Inc. conducted a research and development program designed to establish conditions for ion implantation/mixing of suitable additives into the surfaces of bulk ceramics and metals for obtaining self-lubricating low friction and wear characteristics. The substrates considered were ZrO{sub 2}, Al{sub 2}O{sub 3}, Si{sub 3}N{sub 4}, steel and Ni-base superalloy. The lubricant additives chosen were BaF{sub 2}/CaF{sub 2}Ag, MoS{sub 2}, WS{sub 2}and B{sub 2}O{sub 3}. The initial tasks of the program were to synthesis these lubricant compounds by co-implantation of constituent elements if sufficient beams of desired elements were obtained. The final tasks were to investigate high energy (MeV) ion mixing of deposited coatings as well as to investigate ion beam assisted deposition using low energy ion beams. It was shown that MoS{sub 2} can be synthesized by co-implantation of Mo{sup +} and S{sup +} in ceramic materials with appropriate choice of energies to obtain nearly overlapping depth profiles. The sliding life of DC magnetron sputtered MoS{sub 2} films of thicknesses {approximately}7500{Angstrom} on ceramic materials such as sapphire, Si{sub 3}N{sub 4} and ZrO{sub 3} were improved by ten to thousand fold after 2 Mev Ag{sup +} ion mixing. Ion beam assisted deposition (IBAD) and ion beam mixing were utilized to fabricate self-lubricating coatings of CaF{sub 2}/Ag and BaF/CaF{sub 2}/Ag composites.

  8. 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.

  9. A study of DLC coatings for ironing of stainless steel

    DEFF Research Database (Denmark)

    Sulaiman, Mohd Hafis Bin; Christiansen, Peter; Bay, Niels Oluf

    2017-01-01

    Stamping of sheet metal components without lubrication or using minimum amount of hazard free lubricant is a possible solution to diminish health hazards to personnel and environmental impact and to reduce production costs. This paper studies the application of diamond-like coating (DLC) under...

  10. 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.

  11. ZnO nanorod array solid phase micro-extraction fiber coating: fabrication and extraction capability

    International Nuclear Information System (INIS)

    Wang Dan; Zhang Zhuomin; Li Tiemei; Zhang Lan; Chen Guonan; Luo Lin

    2009-01-01

    In this paper, a ZnO nanorod array has been introduced as a coating to the headspace solid phase micro-extraction (HSSPME) field. The coating shows good extraction capability for volatile organic compounds (VOCs) by use of BTEX as a standard and can be considered suitable for sampling trace and small molecular VOC targets. In comparison with the randomly oriented ZnO nanorod HSSPME coating, ZnO nanorod array HSSPME fiber coating shows better extraction capability, which is attributed to the nanorod array structure of the coating. Also, this novel nanorod array coating shows good extraction selectivity to 1-propanethiol.

  12. Preliminary Results of Cleaning Process for Lubricant Contamination

    Science.gov (United States)

    Eisenmann, D.; Brasche, L.; Lopez, R.

    2006-03-01

    Fluorescent penetrant inspection (FPI) is widely used for aviation and other components for surface-breaking crack detection. As with all inspection methods, adherence to the process parameters is critical to the successful detection of defects. Prior to FPI, components are cleaned using a variety of cleaning methods which are selected based on the alloy and the soil types which must be removed. It is also important that the cleaning process not adversely affect the FPI process. There are a variety of lubricants and surface coatings used in the aviation industry which must be removed prior to FPI. To assess the effectiveness of typical cleaning processes on removal of these contaminants, a study was initiated at an airline overhaul facility. Initial results of the cleaning study for lubricant contamination in nickel, titanium and aluminum alloys will be presented.

  13. Preliminary Results of Cleaning Process for Lubricant Contamination

    International Nuclear Information System (INIS)

    Eisenmann, D.; Brasche, L.; Lopez, R.

    2006-01-01

    Fluorescent penetrant inspection (FPI) is widely used for aviation and other components for surface-breaking crack detection. As with all inspection methods, adherence to the process parameters is critical to the successful detection of defects. Prior to FPI, components are cleaned using a variety of cleaning methods which are selected based on the alloy and the soil types which must be removed. It is also important that the cleaning process not adversely affect the FPI process. There are a variety of lubricants and surface coatings used in the aviation industry which must be removed prior to FPI. To assess the effectiveness of typical cleaning processes on removal of these contaminants, a study was initiated at an airline overhaul facility. Initial results of the cleaning study for lubricant contamination in nickel, titanium and aluminum alloys will be presented

  14. FY 2000 report on the results of the technology development of energy use reduction of machine tools. Development of dry cutting use abrasion resistant/lubricous coated tools; 2000 nendo energy shiyo gorika kosaku kikai nado gijutsu kaihatsu seika hokokusho. Dry sessakuyo taimamo junkatsusei hifuku kogu no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    For the purpose of energy conservation and reduction of environmental loads of machine tools, study was conducted on the dry cutting which is the cutting with no use of cutting oil, and the FY 2000 results were summed up. The study was made on dry cutting use abrasion resistance/lubricous coated tools coated with the composite membrane of which the cutting life become little lower than that of existing tools using coolant. In the survey of abrasion resistant/lubricous films, it was found out that in the adhesion to ultra-hard substrates, the DLC single-layer film consisting only of carbon indicated the same excellent adhesion as intermediate-layer inserts. As to the synthesis of abrasion resistant/lubricous films, the synthesis of the composite membrane (WC/C membrane) consisting of tungsten carbide (WC) and carbon (C) was made using arc ion plating device. The WC/C membrane is composed of W and C and has the structure in which at nm levels the layer with much W and the layer with less W were alternately piled. Study was made of devices necessary for the development of abrasion resistant/lubricous films and the film formation for drill. (NEDO)

  15. 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)

  16. Oxidation behaviour and electrical properties of cobalt/cerium oxide composite coatings for solid oxide fuel cell interconnects

    DEFF Research Database (Denmark)

    Harthøj, Anders; Holt, Tobias; Møller, Per

    2015-01-01

    This work evaluates the performance of cobalt/cerium oxide (Co/CeO2) composite coatings and pure Co coatings to be used for solid oxide fuel cell (SOFC) interconnects. The coatings are electroplated on the ferritic stainless steels Crofer 22 APU and Crofer 22H. Coated and uncoated samples...

  17. 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

    Science.gov (United States)

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

    2014-10-01

    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.

  18. 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.

  19. Tribological Performance of MoS2 Coatings in Various Environments

    Directory of Open Access Journals (Sweden)

    Thomas Gradt

    2016-09-01

    Full Text Available Molybdenum disulfide (MoS2 is a well-known solid lubricant for tribosystems running in vacuum or dry gases. Problems arise due to its sensitivity to humidity, which is a drawback for its application under ambient conditions. However, by using a physical vapor deposition (PVD process, deposition parameters can be optimized not only to gain a coatings structure with favorable frictional properties but also to minimize the sensitivity to attack by water molecules. Therefore, an improved tribological behavior even under moist conditions can be achieved. MoS2 coatings are also candidates for being applied at cryogenic temperatures. They already have proven their suitability, e.g., for sliding support elements between superconducting magnets of the nuclear fusion-experiment Wendelstein 7-X. However, these coatings were exclusively produced for this particular application and the utilization for more common tribosystems may be precluded due to cost considerations. In view of a wider range of applications, pure and Cr containing PVD-MoS2 coatings with an optimized structure were tested under varying environments including hydrogen gas and cryogenic temperatures. Results of the most promising variant are presented in this paper.

  20. Rejection thresholds in solid chocolate-flavored compound coating.

    Science.gov (United States)

    Harwood, Meriel L; Ziegler, Gregory R; Hayes, John E

    2012-10-01

    Classical detection thresholds do not predict liking, as they focus on the presence or absence of a sensation. Recently however, Prescott and colleagues described a new method, the rejection threshold, where a series of forced choice preference tasks are used to generate a dose-response function to determine hedonically acceptable concentrations. That is, how much is too much? To date, this approach has been used exclusively in liquid foods. Here, we determined group rejection thresholds in solid chocolate-flavored compound coating for bitterness. The influences of self-identified preferences for milk or dark chocolate, as well as eating style (chewers compared to melters) on rejection thresholds were investigated. Stimuli included milk chocolate-flavored compound coating spiked with increasing amounts of sucrose octaacetate, a bitter and generally recognized as safe additive. Paired preference tests (blank compared to spike) were used to determine the proportion of the group that preferred the blank. Across pairs, spiked samples were presented in ascending concentration. We were able to quantify and compare differences between 2 self-identified market segments. The rejection threshold for the dark chocolate preferring group was significantly higher than the milk chocolate preferring group (P= 0.01). Conversely, eating style did not affect group rejection thresholds (P= 0.14), although this may reflect the amount of chocolate given to participants. Additionally, there was no association between chocolate preference and eating style (P= 0.36). Present work supports the contention that this method can be used to examine preferences within specific market segments and potentially individual differences as they relate to ingestive behavior. This work makes use of the rejection threshold method to study market segmentation, extending its use to solid foods. We believe this method has broad applicability to the sensory specialist and product developer by providing a

  1. Tribology and coatings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-06-01

    The future use of fuel-efficient, low-emission, advanced transportation systems (for example, those using low-heat-rejection diesel engines or advanced gas turbines) presents new challenges to tribologists and materials scientists. High service temperatures, corrosive environments, and extreme contact pressures are among the concerns that make necessary new tribological designs, novel materials, and effective lubrication concepts. Argonne is working on methods to reduce friction, wear and corrosion, such as soft metal coatings on ceramics, layered compounds, diamond coatings, and hard surfaces.

  2. 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.

  3. 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.

  4. 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.

  5. Oral coatings: a study on the formation, clearance and perception

    OpenAIRE

    Camacho, S.

    2015-01-01

    Oral coatings are residues of food and beverages that coat the oral mucosa after consumption. Several studies have reported on the lubrication properties in mouth, and the after-feel and after-taste impact of oral coatings. Further, oral coatings have been suggested to influence subsequent taste perception. Although it is well known that oral coatings can influence sensory perception, there was little information available on the chemical composition and physical properties of oral coatings. ...

  6. Simulative Testing of Friction and Lubrication in Cold Forging of Steel and Aluminum

    DEFF Research Database (Denmark)

    Ceron, Ermanno; Bay, Niels; Aida, Tetsuo

    2012-01-01

    torque during testing combined with an analysis of the sliding velocity distribution along the punch nose. The latter is determined by FE analysis of the test. Results show friction stress for unalloyed low C-steel provided with different types of lubricants, i.e. phosphate coating plus soap, phosphate...

  7. A study of DLC coatings for ironing of stainless steel

    DEFF Research Database (Denmark)

    Sulaiman, Mohd Hafis Bin; Christiansen, Peter; Bay, Niels Oluf

    2017-01-01

    severe lubrication conditions by adopting strip reduction testing to replicate industrial ironing production of deep drawn, stainless steel cans. Three DLC coatings are investigated; multi-layer, double layer and single layer. Experiments revealed that the double layer coating worked successful, i...

  8. "Insensitive" to touch: fabric-supported lubricant-swollen polymeric films for omniphobic personal protective gear.

    Science.gov (United States)

    Damle, Viraj G; Tummala, Abhishiktha; Chandrashekar, Sriram; Kido, Cassidee; Roopesh, Ajay; Sun, Xiaoda; Doudrick, Kyle; Chinn, Jeff; Lee, James R; Burgin, Timothy P; Rykaczewski, Konrad

    2015-02-25

    The use of personal protective gear made from omniphobic materials that easily shed drops of all sizes could provide enhanced protection from direct exposure to most liquid-phase biological and chemical hazards and facilitate the postexposure decontamination of the gear. In recent literature, lubricated nanostructured fabrics are seen as attractive candidates for personal protective gear due to their omniphobic and self-healing characteristics. However, the ability of these lubricated fabrics to shed low surface tension liquids after physical contact with other objects in the surrounding, which is critical in demanding healthcare and military field operations, has not been investigated. In this work, we investigate the depletion of oil from lubricated fabrics in contact with highly absorbing porous media and the resulting changes in the wetting characteristics of the fabrics by representative low and high surface tension liquids. In particular, we quantify the loss of the lubricant and the dynamic contact angles of water and ethanol on lubricated fabrics upon repeated pressurized contact with highly absorbent cellulose-fiber wipes at different time intervals. We demonstrate that, in contrast to hydrophobic nanoparticle coated microfibers, fabrics encapsulated within a polymer that swells with the lubricant retain the majority of the oil and are capable of repelling high as well as low surface tension liquids even upon multiple contacts with the highly absorbing wipes. The fabric supported lubricant-swollen polymeric films introduced here, therefore, could provide durable and easy to decontaminate protection against hazardous biological and chemical liquids.

  9. 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)

  10. 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.

  11. Drop Printing of Pharmaceuticals: Effect of Molecular Weight on PEG Coated-Naproxen/PEG3350 Solid Dispersions.

    Science.gov (United States)

    Hsu, Hsin-Yun; Toth, Scott; Simpson, Garth J; Harris, Michael T

    2015-12-01

    Solid dispersions have been used to enhance the bioavailability of poorly water-soluble active pharmaceutical ingredients (APIs). However, the solid state phase, compositional uniformity, and scale-up problems are issues that need to be addressed. To allow for highly controllable products, the Drop Printing (DP) technique can provide precise dosages and predictable compositional uniformity of APIs in two/three dimensional structures. In this study, DP was used to prepare naproxen (NAP)/polyethylene glycol 3350 (PEG3350) solid dispersions with PEG coatings of different molecular weights (MW). A comparison of moisture-accelerated crystallization inhibition by different PEG coatings was assessed. Scanning electron microscopy (SEM), second harmonic generation (SHG) microscopy, and differential scanning calorimetry (DSC) analysis were performed to characterize the morphology and quantify the apparent crystallinity of NAP within the solid dispersions. Thermogravimetric analysis (TGA) was employed to measure the water content within each sample. The results suggest that the moisture-accelerated crystallization inhibition capability of the PEG coatings increased with increasing MW of the PEG coating. Besides, to demonstrate the flexibility of DP technology on manufacturing formulation, multilayer tablets with different PEG serving as barrier layers were also constructed, and their dissolution behavior was examined. By applying DP and appropriate materials, it is possible to design various carrier devices used to control the release dynamics of the API.

  12. Tribological investigation of diamond-like carbon coated micro-dimpled surface under bovine serum and osteoarthritis oriented synovial fluid

    International Nuclear Information System (INIS)

    Ghosh, Subir; Roy, Taposh; Pingguan-Murphy, Belinda; Choudhury, Dipankar; Bin Mamat, Azuddin; Masjuki, H H

    2015-01-01

    Osteoarthritis-oriented synovial fluid (OASF), i.e., that typical of a patient with osteoarthritis, has different physical and biological characteristics than bovine serum (BS), a lubricant widely used in biotribological investigations. Micro-dimpled and diamond-like carbon- (DLC) coated surfaces are key emerging interfaces for orthopedic implants. In this study, tribological performances of dimpled surfaces, with and without DLC coating, have been investigated under both BS and OASF. The friction tests were performed utilizing a pin on a disk tribometer, whereas contact pressure, speed, and temperature were simulated to a ‘medium walking gait’ of hip joint conditions. The mechanical properties of the specimen and the physical properties of the lubricant were characterized before the friction test. Raman analysis was conducted to identify the coating condition both before and after the test. The DLC-coated dimpled surface showed maximum hardness and residual stress. A DLC-coated dimpled surface under an OASF lubricated condition yielded a lower friction coefficient and wear compared to those of plain and dimpled specimens. The higher graphitization of coated materials with increasing load was confirmed by Raman spectroscopy. (paper)

  13. Tribological investigation of diamond-like carbon coated micro-dimpled surface under bovine serum and osteoarthritis oriented synovial fluid

    Science.gov (United States)

    Ghosh, Subir; Choudhury, Dipankar; Roy, Taposh; Mamat, Azuddin Bin; Masjuki, H. H.; Pingguan-Murphy, Belinda

    2015-06-01

    Osteoarthritis-oriented synovial fluid (OASF), i.e., that typical of a patient with osteoarthritis, has different physical and biological characteristics than bovine serum (BS), a lubricant widely used in biotribological investigations. Micro-dimpled and diamond-like carbon- (DLC) coated surfaces are key emerging interfaces for orthopedic implants. In this study, tribological performances of dimpled surfaces, with and without DLC coating, have been investigated under both BS and OASF. The friction tests were performed utilizing a pin on a disk tribometer, whereas contact pressure, speed, and temperature were simulated to a ‘medium walking gait’ of hip joint conditions. The mechanical properties of the specimen and the physical properties of the lubricant were characterized before the friction test. Raman analysis was conducted to identify the coating condition both before and after the test. The DLC-coated dimpled surface showed maximum hardness and residual stress. A DLC-coated dimpled surface under an OASF lubricated condition yielded a lower friction coefficient and wear compared to those of plain and dimpled specimens. The higher graphitization of coated materials with increasing load was confirmed by Raman spectroscopy.

  14. 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.

  15. Flexible diamond-like carbon film coated on rubber

    NARCIS (Netherlands)

    Pei, Y.T.; Bui, X.L.; Pal, J.P. van der; Martinez-Martinez, D.; Hosson, J.Th.M. De

    2013-01-01

    Dynamic rubber seals are major sources of friction of lubrication systems and bearings, which may take up to 70% of the total friction. The solution we present is to coat rubbers with diamond-like carbon (DLC) thin films by which the coefficient of friction is reduced to less than one tenth. Coating

  16. Sol-Gel Derived, Nanostructured Oxide Lubricant Coatings

    National Research Council Canada - National Science Library

    Taylor, Douglas

    2000-01-01

    In this program, we deposited oxide coatings of titanium and nickel by wet-chemical deposition methods, also referred to as sol-gel, which showed excellent tribological properties in previous investigations...

  17. Evaluation of risk and benefit in thermal effusivity sensor for monitoring lubrication process in pharmaceutical product manufacturing.

    Science.gov (United States)

    Uchiyama, Jumpei; Kato, Yoshiteru; Uemoto, Yoshifumi

    2014-08-01

    In the process design of tablet manufacturing, understanding and control of the lubrication process is important from various viewpoints. A detailed analysis of thermal effusivity data in the lubrication process was conducted in this study. In addition, we evaluated the risk and benefit in the lubrication process by a detailed investigation. It was found that monitoring of thermal effusivity detected mainly the physical change of bulk density, which was changed by dispersal of the lubricant and the coating powder particle by the lubricant. The monitoring of thermal effusivity was almost the monitoring of bulk density, thermal effusivity could have a high correlation with tablet hardness. Moreover, as thermal effusivity sensor could detect not only the change of the conventional bulk density but also the fractional change of thermal conductivity and thermal capacity, two-phase progress of lubrication process could be revealed. However, each contribution of density, thermal conductivity, or heat capacity to thermal effusivity has the risk of fluctuation by formulation. After carefully considering the change factor with the risk to be changed by formulation, thermal effusivity sensor can be a useful tool for monitoring as process analytical technology, estimating tablet hardness and investigating the detailed mechanism of the lubrication process.

  18. 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)

  19. 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.

  20. 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.

  1. 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

  2. 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)

  3. A review on procedures for the preparation of coatings for solid phase microextraction

    International Nuclear Information System (INIS)

    Aziz-Zanjani, Mohammad Ovais; Mehdinia, Ali

    2014-01-01

    Introduced in the 1990s, solid-phase microextraction (SPME) has found numerous applications. This is due to the solventless nature of SPME and the large variety of sorbents and coatings available. Highly diverse procedures have been applied to coat supports such as fused silica fibers or metal wires with sorbents in order to enhance capability, selectivity and robustness of SPME. Lately, research also is directed towards more simple methods for deposition of different types of coatings. Several of these methods have resulted in better stability and higher effective surface areas of the coatings. This review (with 128 references) covers the state of the art in methods for coating materials for use in SPME. It is divided into the following sections: (a) Dip methods and physical agglutination methods, (b) sol-gel technology, (c) chemical grafting, (d) electrochemical methods for coating (such as electrodeposition, anodizing and electrophoretic deposition), (e) electrospinning, (f) liquidphase deposition, and (g) hydrothermal methods. A final section covers conclusions and future trends. (author)

  4. Microstructure and wear behavior of γ/Al4C3/TiC/CaF2 composite coating on γ-TiAl intermetallic alloy prepared by Nd:YAG laser cladding

    International Nuclear Information System (INIS)

    Liu Xiubo; Shi Shihong; Guo Jian; Fu Geyan; Wang Mingdi

    2009-01-01

    As a further step in obtaining high performance elevated temperature self-lubrication anti-wear composite coatings on TiAl alloy, a novel Ni-P electroless plating method was adopted to encapsulate the as-received CaF 2 in the preparation of precursor NiCr-Cr 3 C 2 -CaF 2 mixed powders with an aim to decrease its mass loss and increase its compatibility with the metal matrix during a Nd:YAG laser cladding. The microstructure of the coating was examined using X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) and the friction and wear behavior of the composite coatings sliding against the hardened 0.45% C steel ring was evaluated using a block-on-ring wear tester at room temperature. It was found that the coating had a unique microstructure consisting of primary dendrites TiC and block Al 4 C 3 carbides reinforcement as well as fine isolated spherical CaF 2 solid lubrication particles uniformly dispersed in the NiCrAlTi (γ) matrix. The good friction-reducing and anti-wear abilities of the laser clad composite coating was suggested to the Ni-P electroless plating and the attendant reduction of mass loss of CaF 2 and the increasing of it's wettability with the NiCrAlTi (γ) matrix during the laser cladding process

  5. Thermal–Hydrodynamic Behaviour of Coated Pivoted Pad Thrust Bearings: Comparison between Babbitt, PTFE and DLC

    OpenAIRE

    Konstantinos Katsaros; Dimitrios A. Bompos; Pantelis G. Nikolakopoulos; Stephanos Theodossiades

    2018-01-01

    The hydrodynamic lubrication and thermal analysis of tilting pad thrust bearings has been a major subject for many studies in the field of tribology. There is only a limited number of studies regarding thrust bearings with coated surfaces. The purpose of this study is to build a parametric, iterative algorithm in order to perform a complete thermal and hydrodynamic lubrication analysis for pivoted pad thrust bearings with coatings. The analytical model is mainly based on the energy, continuit...

  6. 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.

  7. Low friction slip-rolling contacts. Influences of alternative steels, high performance thin film coatings and lubricants

    Energy Technology Data Exchange (ETDEWEB)

    Scholz, Christian

    2013-02-01

    Due to the growing environmental awareness worldwide, containment provisions for CO{sub 2} emissions in mobility systems and increasing performance requirements the demands on mechanical systems and their materials continuously rise. These high demands require the implementation of new technical approaches, for example of light-weight strategies in automotive powertrains, and directly raise questions about the suitability of the most promising technical solution. Two basic parameters, the surface hardness of the tooth flanks and the core fatigue strength of the tooth root, illustrate exemplarily increasing demands on material grades used for gear wheels in automotive powertrains. In addition to light-weight strategies, a reduction in friction and an increase of the fatigue lifetime are two other major development directions to strive the mentioned targets. It is clear that any kind of solution must show an equal application profile, preferably an improvement, compared to the state-of-the-art solutions. For tribological systems, the following paths may offer lower friction and higher load carrying capabilities: 1. Alternative base oils and additives (such as esters, polyglycols), 2. Thin film coatings (e.g. DLC) and/or 3. Novel steel metallurgies. In previous investigations on the slip-rolling resistance of thin film coatings (a-C, ta-C, Zr(C,N)) the substrates were mainly made of the bearing steels 100Cr6H and Cronidur 30. Applying contact pressures of up to P{sub 0max} = 2.9 GPa (F{sub N} = 2,000 N), the samples were tested up to 10 million load cycles in endurance tests. The aim of the present work is to broaden the research by varying the input parameters. Newly developed engine oil mixtures, high performance thin film coatings and alternative steel solutions are intensively investigated in highly stressed slip-rolling contacts at lubricant temperatures of 120 C. Specifically, in using new steel metallurgies, i.e. the high toughness and high strength steels V300

  8. Application of Triton X-100 coated poly vinyl chloride as new solid ...

    African Journals Online (AJOL)

    The influences of the analytical parameters including pH, ligand amount, surfactant type and concentration, eluting condition and sample volume on metal ions recovery were investigated. The method has been ... KEY WORDS: Surfactant coated PVC, Atomic absorption spectrometry, Solid phase extraction. Bull. Chem. Soc.

  9. 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.

  10. Development, characterization and testing of tungsten doped DLC coatings for dry rotary swaging

    Directory of Open Access Journals (Sweden)

    Hasselbruch Henning

    2015-01-01

    Full Text Available The extensive use of lubricant during rotary swaging is particularly required for a good surface finish of the work piece and the reduction of tool wear. Abandonment of lubricant would improve the ecological process-balance and could also accelerate for further work piece refinements. Also cleaning of the manufactured components becomes obsolete. Thus, a dry machining is highly innovative, consequently new strategies to substitute the lubricant functions become necessary. To encounter the changed tribological conditions due to dry rotary swaging, low friction, tungsten doped, hard DLC coatings and structured surfaces are the most promising approaches. In this work the development of hard coating by means of reactive magnetron sputtering is presented, a promising layer variant is deposited on a set of tools and then tested and investigated in real use.

  11. 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.

  12. 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 ...

  13. 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

  14. The role of phosphate conversion coatings in make-up of casing connections

    NARCIS (Netherlands)

    Ernens, D; van Riet, E.J.; de Rooij, M.B.; Pasaribu, H.R.; van Haaften, W.M.; Schipper, D.J.

    2017-01-01

    Phosphate conversion coatings are widely used on (premium) casing connections for protection against corrosion. Next to that, in conjunction with the lubricant these coatings provide galling protection. The friction and wear that occurs during make-up and subsequent load cycling determines the

  15. Polymeric ionic liquid coatings versus commercial solid-phase microextraction coatings for the determination of volatile compounds in cheeses.

    Science.gov (United States)

    Trujillo-Rodríguez, María J; Yu, Honglian; Cole, William T S; Ho, Tien D; Pino, Verónica; Anderson, Jared L; Afonso, Ana M

    2014-04-01

    The extraction performance of four polymeric ionic liquid (PIL)-based solid-phase microextraction (SPME) coatings has been studied and compared to that of commercial SPME coatings for the extraction of 16 volatile compounds in cheeses. The analytes include 2 free fatty acids, 2 aldehydes, 2 ketones and 10 phenols and were determined by headspace (HS)-SPME coupled to gas chromatography (GC) with flame-ionization detection (FID). The PIL-based coatings produced by UV co-polymerization were more efficient than PIL-based coatings produced by thermal AIBN polymerization. Partition coefficients of analytes between the sample and the coating (Kfs) were estimated for all PIL-based coatings and the commercial SPME fiber showing the best performance among the commercial fibers tested: carboxen-polydimethylsyloxane (CAR-PDMS). For the PIL-based fibers, the highest K(fs) value (1.96 ± 0.03) was obtained for eugenol. The normalized calibration slope, which takes into account the SPME coating thickness, was also used as a simpler approximate tool to compare the nature of the coating within the determinations, with results entirely comparable to those obtained with estimated K(fs) values. The PIL-based materials obtained by UV co-polymerization containing the 1-vinyl-3-hexylimidazolium chloride IL monomer and 1,12-di(3-vinylimiazolium)dodecane dibromide IL crosslinker exhibited the best performance in the extraction of the select analytes from cheeses. Despite a coating thickness of only 7 µm, this copolymeric sorbent coating was capable of quantitating analytes in HS-SPME in a 30 to 2000 µg L(-1) concentration range, with correlation coefficient (R) values higher than 0.9938, inter-day precision values (as relative standard deviation in %) varying from 6.1 to 20%, and detection limits down to 1.6 µg L(-1). Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Investigation of metallurgical coatings for automotive applications

    Science.gov (United States)

    Su, Jun Feng

    Metallurgical coatings have been widely used in the automotive industry from component machining, engine daily running to body decoration due to their high hardness, wear resistance, corrosion resistance and low friction coefficient. With high demands in energy saving, weight reduction and limiting environmental impact, the use of new materials such as light Aluminum/magnesium alloys with high strength-weight ratio for engine block and advanced high-strength steel (AHSS) with better performance in crash energy management for die stamping, are increasing. However, challenges are emerging when these new materials are applied such as the wear of the relative soft light alloys and machining tools for hard AHSS. The protective metallurgical coatings are the best option to profit from these new materials' advantages without altering largely in mass production equipments, machinery, tools and human labor. In this dissertation, a plasma electrolytic oxidation (PEO) coating processing on aluminum alloys was introduced in engine cylinder bores to resist wear and corrosion. The tribological behavior of the PEO coatings under boundary and starve lubrication conditions was studied experimentally and numerically for the first time. Experimental results of the PEO coating demonstrated prominent wear resistance and low friction, taking into account the extreme working conditions. The numerical elastohydrodynamic lubrication (EHL) and asperity contact based tribological study also showed a promising approach on designing low friction and high wear resistant PEO coatings. Other than the fabrication of the new coatings, a novel coating evaluation methodology, namely, inclined impact sliding tester was presented in the second part of this dissertation. This methodology has been developed and applied in testing and analyzing physical vapor deposition (PVD)/ chemical vapor deposition (CVD)/PEO coatings. Failure mechanisms of these common metallurgical hard coatings were systematically

  17. 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.

  18. 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.

  19. Self-Organization of Friction Surface of Fe-Mn-C-B Coating With Increased Resistance to Abrasion / Samoorganizacja Powierzchni Tarcia Powłoki Fe-Mn-C-B O Zwiększonej Odporności Na Zużycie Ścierne

    Directory of Open Access Journals (Sweden)

    Barszcz M.

    2015-12-01

    Full Text Available The paper concerns the research on self-organization of the surface of coating of hypoeutectic alloy Fe-Mn-C-B modified Si, Ni, Cr, Cu with friction with C45 steel. The coatings were obtained by arc welding using a flux-cored wire. Tests of resistance to wear were carried out for hypoeutectic coatings with use of the friction pair pin-on-disc in the conditions of sliding friction, in model lubricating environments. The surface-active (glycerol oil and inactive (Vaseline grease lubricant was used. Tribological tests carried out showed that cooperation of hypoeutectic alloy coating with counterbody of C45 steel with lubrication with surface-active lubricant results in a significant improvement in tribological properties than in case of the lubrication with surface-inactive lubricant. The resulting effect is related to the self-organization of friction surface. After deposition and wear resistance tests, the friction surface microstructure was analysed, as well as the surface and depth distribution of the elements.

  20. Numerical investigation of solid mixing in a fluidized bed coating process

    Science.gov (United States)

    Kenche, Venkatakrishna; Feng, Yuqing; Ying, Danyang; Solnordal, Chris; Lim, Seng; Witt, Peter J.

    2013-06-01

    Fluidized beds are widely used in many process industries including the food and pharmaceutical sectors. Despite being an intensive research area, there are no design rules or correlations that can be used to quantitatively predict the solid mixing in a specific system for a given set of operating conditions. This paper presents a numerical study of the gas and solid dynamics in a laboratory scale fluidized bed coating process used for food and pharmaceutical industries. An Eulerian-Eulerian model (EEM) with kinetic theory of granular flow is selected as the modeling technique, with the commercial computational fluid dynamics (CFD) software package ANSYS/Fluent being the numerical platform. The flow structure is investigated in terms of the spatial distribution of gas and solid flow. The solid mixing has been evaluated under different operating conditions. It was found that the solid mixing rate in the horizontal direction is similar to that in the vertical direction under the current design and operating conditions. It takes about 5 s to achieve good mixing.

  1. High temperature tribological properties of plasma-sprayed metallic coatings containing ceramic particles

    International Nuclear Information System (INIS)

    Dallaire, S.; Legoux, J.G.

    1995-01-01

    For sealing a moving metal component with a dense silica-based ceramic pre-heated at 800 C, coatings with a low coefficient of friction and moderate wear loss are required. As reported previously, plasma-sprayed coatings containing solid lubricants could reduce sliding wear in high-temperature applications. Plasma-sprayed metal-based coatings containing ceramic particles have been considered for high temperature sealing. Selected metal powders (NiCoCrAlY, CuNi, CuNiIn, Ag, Cu) and ceramic particles (boron nitride, Zeta-B ceramic) were agglomerated to form suitable spray powders. Plasma-sprayed composite coatings and reference materials were tested in a modified pin-on-disc apparatus in which the stationary disc consisted of a dense silica-based ceramic piece initially heated at 800 C and allowed to cool down during tests. The influence of single exposure and repeated contacts with a dense silica-based ceramic material pre-heated to 800 C on the coefficient of friction, wear loss and damage to the ceramic piece was evaluated. Being submitted to a single exposure at high temperature, coatings containing malleable metals such as indium, silver and copper performed well. The outstanding tribological characteristics of the copper-Zeta-B ceramic coating was attributed to the formation of a glazed layer on the surface of this coating which lasted over exposures to high temperature. This glazed layer, composed of fine oxidation products, provided a smooth and polished surface and helped maintaining the coefficient of friction low

  2. Thermal–Hydrodynamic Behaviour of Coated Pivoted Pad Thrust Bearings: Comparison between Babbitt, PTFE and DLC

    Directory of Open Access Journals (Sweden)

    Konstantinos Katsaros

    2018-05-01

    Full Text Available The hydrodynamic lubrication and thermal analysis of tilting pad thrust bearings has been a major subject for many studies in the field of tribology. There is only a limited number of studies regarding thrust bearings with coated surfaces. The purpose of this study is to build a parametric, iterative algorithm in order to perform a complete thermal and hydrodynamic lubrication analysis for pivoted pad thrust bearings with coatings. The analytical model is mainly based on the energy, continuity and Navier–Stokes equations, which are solved numerically with the Semi-Implicit Method for Pressure Linked Equations Consistent (SIMPLEC method. The analysis focuses on a single pivoted pad of the thrust bearing. The thermal properties of the coating material are taken into account and the resulting thermal and flow fields are solved. The basic hydrodynamic and tribological characteristics are calculated for an uncoated, a Babbitt coated, a PTFE coated and a diamond like carbon (DLC coated pivoted pad thrust bearing. The pressure and the film thickness distribution, as well as the load capacity and the frictional forces, are determined for several pad positions and velocities of the rotor. A mineral oil lubricant is used to estimate the shear thinning or thickening effects on the pad tribological performance. The results indicate that pads coated with PTFE and DLC show lower friction forces compared to the common steel and Babbitt applications. At the same time, the DLC coating seems to affect the bearing’s flow and thermal fields less than the PTFE, making it more suitable for thrust bearings applications.

  3. ZnO nanorod array polydimethylsiloxane composite solid phase micro-extraction fiber coating: fabrication and extraction capability.

    Science.gov (United States)

    Wang, Dan; Wang, Qingtang; Zhang, Zhuomin; Chen, Guonan

    2012-01-21

    ZnO nanorod array coating is a novel kind of solid-phase microextraction (SPME) fiber coating which shows good extraction capability due to the nanostructure. To prepare the composite coating is a good way to improve the extraction capability. In this paper, the ZnO nanorod array polydimethylsiloxane (PDMS) composite SPME fiber coating has been prepared and its extraction capability for volatile organic compounds (VOCs) has been studied by headspace sampling the typical volatile mixed standard solution of benzene, toluene, ethylbenzene and xylene (BTEX). Improved detection limit and good linear ranges have been achieved for this composite SPME fiber coating. Also, it is found that the composite SPME fiber coating shows good extraction selectivity to the VOCs with alkane radicals.

  4. Graphene as a protective coating and superior lubricant for electrical contacts

    Science.gov (United States)

    Berman, Diana; Erdemir, Ali; Sumant, Anirudha V.

    2014-12-01

    Potential for graphene to be used as a lubricant for sliding electrical contacts has been evaluated. Graphene, being deposited as a sporadic flakes on the gold substrate sliding against titanium nitride ball shows not only significant improvement in tribological behavior by reducing both friction (by factor of 2-3) and wear (by 2 orders) but also, even more importantly, demonstrates stable and low electrical resistance at the sliding contacts undergoing thousands of sliding passes regardless of the test environment (i.e., both in humid and dry conditions).

  5. Application of Hard Coatings for Improved Tribological Performance of Blanking and Piercing Tools

    DEFF Research Database (Denmark)

    Podgornik, B.; Zajec, B.; Bay, Niels

    2010-01-01

    The aim of the present investigation was to examine the possibility of reducing lubrication and replacing expensive tungsten carbide material in blanking/piercing through introduction of hard tool coatings. Results show that hard PVD coatings can be successfully used in blanking/piercing applicat...

  6. 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.

  7. Neutron-reflectometry study of alcohol adsorption on various DLC coatings

    Energy Technology Data Exchange (ETDEWEB)

    Kalin, M., E-mail: mitjan.kalin@tint.fs.uni-lj.si [University of Ljubljana, Faculty of Mechanical Engineering, Laboratory for Tribology and Interface Nanotechnology, Bogišićeva 8, 1000 Ljubljana (Slovenia); Simič, R. [University of Ljubljana, Faculty of Mechanical Engineering, Laboratory for Tribology and Interface Nanotechnology, Bogišićeva 8, 1000 Ljubljana (Slovenia); Hirayama, T. [Department of Mechanical Engineering, Doshisha University, 1-3 Miyakodani, Tatara, Kyotanabe, Kyoto 610-0394 (Japan); Geue, T.; Korelis, P. [Paul Scherrer Institute, 5232 Villigen – PSI (Switzerland)

    2014-01-01

    Diamond-like carbon (DLC) coatings are notable for their excellent tribological properties. Our understanding of the lubrication of DLC coatings has improved drastically over the past decade. However, only a few details are known about the properties of the adsorbed layers on DLC, which crucially affect their tribological properties under lubricated conditions. In this work we used neutron reflectometry to determine the thickness and the density of adsorbed layers of alcohol molecules on several different types of DLC coatings, i.e., non-hydrogenated (a-C) and hydrogenated, of which both non-doped (a-C:H) and doped (a-C:H:F and a-C:H:Si) coatings were used. The results showed that a 0.9-nm-thick and relatively dense (≈45%) layer of alcohol adsorbed on the a-C coating. In contrast, no adsorption layer was found on the a-C:H, confirming the important role of hydrogen, which predominantly acts as a dangling-bond passivation source and affects the reactivity and tribochemistry of DLC coatings. The incorporation of F into a DLC coating also did not cause an increase in the adsorption ability with respect to alcohol molecules. On the contrary, the incorporation of Si increased the reactivity of the DLC coating so that a 1.3-nm-thick alcohol layer with a 35% bulk density was detected on the surface. We also discuss the very good agreement of the current results with the surface energy of selected coatings found in these experiments.

  8. Study of organic ablative thermal-protection coating for solid rocket motor

    Science.gov (United States)

    Hua, Zenggong

    1992-06-01

    A study is conducted to find a new interior thermal-protection material that possesses good thermal-protection performance and simple manufacturing possibilities. Quartz powder and Cr2O3 are investigated using epoxy resin as a binder and Al2O3 as the burning inhibitor. Results indicate that the developed thermal-protection coating is suitable as ablative insulation material for solid rocket motors.

  9. 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.

  10. Effects of molybdenum dithiocarbamate and zinc dialkyl dithiophosphate additives on tribological behaviors of hydrogenated diamond-like carbon coatings

    International Nuclear Information System (INIS)

    Yue, Wen; Liu, Chunyue; Fu, Zhiqiang; Wang, Chengbiao; Huang, Haipeng; Liu, Jiajun

    2014-01-01

    Highlights: • For MoDTC, DLC coating showed better anti-friction and worse anti-wear behaviors. • The improved anti-friction property was due to graphitization and MoS 2 . • Formation of MoO x resulted in a high wear volume. • For ZDDP, DLC coating showed the best anti-wear and the worst anti-friction behaviors. • Absence of friction reducing product and graphitized layer resulted in a higher friction. - Abstract: The tribological behaviors of hydrogenated diamond-like carbon (DLC) coatings under varied load conditions lubricated with polyalpha olefin (PAO), molybdenum dithiocarbamate (MoDTC) and zinc dialkyl dithiophosphate (ZDDP) additives were investigated in this paper. Hydrogenated DLC coatings were synthesized through the decomposition of acetylene by the ion source. The tribological performances were measured on a SRV tribometer. The morphologies and chemical structures of the DLC coatings were investigated by the scanning electron microscope (SEM), Raman spectrometer (Raman) and X-ray photoelectron spectroscope (XPS). It was shown that the low friction and high wear were achieved on the hydrogenated DLC coating under MoDTC lubrication, while low wear was found on the hydrogenated DLC coating lubricated by ZDDP. The primary reason was attributed to different tribofilms formed on the contact area and the formation of graphitic layer. Both factors working together leaded to quite different tribological behaviors

  11. Metal-organic aerogel as a coating for solid-phase microextraction

    Energy Technology Data Exchange (ETDEWEB)

    Saraji, Mohammad, E-mail: saraji@cc.iut.ac.ir; Shahvar, Ali

    2017-06-22

    An iron-based metal-organic aerogel was synthesized using metal-organic framework nanoparticles and applied as a fiber coating for solid-phase microextraction (SPME). Chemical, thermal and morphological characteristics of the material were investigated. Headspace SPME followed by gas chromatography-electron capture detection was used for the determination of chlorobenzenes in the environmental samples. The key experimental factors affecting the extraction efficiency of the analytes, such as ionic strength, extraction and desorption temperature, and extraction time were investigated and optimized. The applicability of the coating for the extraction of chlorobenzenes from the environmental samples including river and tap water, sludge, and coastal soil was evaluated. The detection limits were in the range of 0.1–60 ng L{sup −1}. The relative standard deviations were between 2.0 and 5.0%. The extraction recovery of the analytes was in the range of 88–100%. Compared to the commercial PDMS fiber, the present fiber showed better extraction efficiency. - Highlights: • Metal-organic aerogel was synthesized and used as a novel fiber coating for SPME. • The new coating material showed high surface area and good thermal stability. • GC-ECD was used for determination of chlorobenzenes in environmental samples. • The method showed fast extraction and better efficiency than PDMS commercial fiber.

  12. TOPICAL REVIEW Warm spraying—a novel coating process based on high-velocity impact of solid particles

    Directory of Open Access Journals (Sweden)

    Seiji Kuroda et al

    2008-01-01

    Full Text Available In recent years, coating processes based on the impact of high-velocity solid particles such as cold spraying and aerosol deposition have been developed and attracting much industrial attention. A novel coating process called 'warm spraying' has been developed, in which coatings are formed by the high-velocity impact of solid powder particles heated to appropriate temperatures below the melting point of the powder material. The advantages of such process are as follows: (1 the critical velocity needed to form a coating can be significantly lowered by heating, (2 the degradation of feedstock powder such as oxidation can be significantly controlled compared with conventional thermal spraying where powder is molten, and (3 various coating structures can be realized from porous to dense ones by controlling the temperature and velocity of the particles. The principles and characteristics of this new process are discussed in light of other existing spray processes such as high-velocity oxy-fuel spraying and cold spraying. The gas dynamics of particle heating and acceleration by the spraying apparatus as well as the high-velocity impact phenomena of powder particles are discussed in detail. Several examples of depositing heat sensitive materials such as titanium, metallic glass, WC–Co cermet and polymers are described with potential industrial applications.

  13. 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)

  14. Microstructural and electrical characterization of Mn-Co spinel protective coatings for solid oxide cell interconnects

    DEFF Research Database (Denmark)

    Molin, S.; Sabato, A. G.; Bindi, M.

    2017-01-01

    Electrophoretic deposition, thermal co-evaporation and RF magnetron sputtering methods are used for the preparation of Mn-Co based ceramic coatings for solid oxide fuel cell steel interconnects. Both thin and relatively thick coatings (1–15 μm) are prepared and characterised for their potential...... protective behaviour. Mn-Co coated Crofer22APU samples are electrically tested for 5000 h at 800 °C under a 500 mA cm−2 current load to determine their Area Specific Resistance increase due to a growing chromia scale. After tests, samples are analysed by scanning and transmission electron microscopy....... Analysis is focused on the potential chromium diffusion to or through the coating, the oxide scale thickness and possible reactions at the interfaces. The relationships between the coating type, thickness and effectiveness are reviewed and discussed. Out of the three Mn-Co coatings compared in this study...

  15. Thermal Stability and Oxidation Resistance of Nanocomposite TiC/a-C Protective Coatings

    NARCIS (Netherlands)

    Martinez-Martinez, Diego; Lopez-Cartes, Carlos; Gago, Raul; Fernandez, Asuncion; Carlos Sanchez-Lopez, Juan

    2009-01-01

    Nanocomposite films composed by small crystallites of hard phases embedded in an amorphous lubricant matrix have been extensively studied as protective coatings. These kinds of coatings have often to work in extreme environments, exposed to high temperatures (above 800-900 degrees C), and/or

  16. Flexible diamond-like carbon thin film coated rubbers: fundamentals and applications

    NARCIS (Netherlands)

    Pei, Y.T.

    2015-01-01

    Dynamic rubber seals are major sources of friction of lubrication systems and bearings, which may take up to 75% of the total friction. The solution we present is to coat rubbers with diamond-like carbon (DLC) thin film, by which the coefficient of friction is reduced to less than one tenth. Coating

  17. The Tribological Behaviors of Three Films Coated on Biomedical Titanium Alloy by Chemical Vapor Deposition

    Science.gov (United States)

    Wang, Song; Liao, Zhenhua; Liu, Yuhong; Liu, Weiqiang

    2015-11-01

    Three thin films (DLC, a-C, and TiN) were performed on Ti6Al4V by chemical vapor deposition. Carbon ion implantation was pretreated for DLC and a-C films while Ti transition layer was pretreated for TiN film to strengthen the bonding strength. X-ray diffraction, Raman measurement, nano-hardness and nano-scratch tester, and cross-section etching by FIB method were used to analyze film characteristics. Tribological behaviors of these coatings were studied by articulation with both ZrO2 and UHMWPE balls using ball-on-disk sliding. The thickness values reached ~0.46, ~0.33, and ~1.67 μm for DLC, a-C, and TiN film, respectively. Nano-hardness of the coatings compared with that of untreated and bonding strength (critical load in nano-scratch test) values of composite coatings compared with that of monolayer film all increased significantly, respectively. Under destructive test (ZrO2 ball conterface) in bovine serum lubrication, TiN coating revealed the best wear resistance while DLC showed the worst. Film failure was mainly attributed to the plowing by hard ZrO2 ball characterized by abrasive and adhesive wear. Under normal test (UHMWPE ball conterface), all coatings showed significant improvement in wear resistance both in dry sliding and bovine serum lubrication. Both DLC and a-C films showed less surface damage than TiN film due to the self-lubricating phenomenon in dry sliding. TiN film showed the largest friction coefficient both in destructive and normal tests, devoting to the big TiN grains thus leading to much rougher surface and then a higher value. The self-lubricating film formed on DLC and a-C coating could also decrease their friction coefficients. The results indicated that three coatings revealed different wear mechanisms, and thick DLC or a-C film was more promising in application in lower stress conditions such as artificial cervical disk.

  18. Effect of lubricant on the reliability of dental implant abutment screw joint: An in vitro laboratory and three-dimension finite element analysis.

    Science.gov (United States)

    Wu, Tingting; Fan, Hongyi; Ma, Ruiyang; Chen, Hongyu; Li, Zhi; Yu, Haiyang

    2017-06-01

    Biomechanical factors play a key role in the success of dental implants. Fracture and loosening of abutment screws are major issues. This study investigated the effect of lubricants on the stability of dental implant-abutment connection. As lubricants, graphite and vaseline were coated on the abutment screw surface, respectively, and a blank without lubricant served as the control. The total friction coefficient (μ tot ), clamping force, fatigue behavior and detorque of the joint combined with dynamic cyclic loading were measured under different lubricating conditions. Further, a three-dimensional finite element analysis was used to investigate stress distribution, in conjunction with experimental images. The results showed that the lubricant reduced μ tot , which in turn led to an increase in clamping force. Decrease in loading increased the fatigue life of the screw. However, use of lubricant at high load reduced the fatigue life. Ductile fracture at the first thread of the screw was the chief failure mode, which was due to maximum von Mises stress. Higher stress levels occurred in the lubricant groups. Lubricated screws resulted in lower detorque which made the joint easier to loosen. In conclusion, the lubricant cannot effectively improve the reliability of dental implant-abutment connection. Keeping the interfaces of implant-screw uncontaminated and strengthening the surface of the screw may be recommend for clinical operation and future design. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Organic transistors fabricated by contact coating at liquid-solid interface for nano-structures

    Directory of Open Access Journals (Sweden)

    Yu-Wen Cheng

    2015-10-01

    Full Text Available A contact coating method is developed to cover the nano-channels with 100 nm or 200 nm diameter and 400 nm depth with a poly(4-vinylphenol (PVP. In such coating the nano-channels faces downwards and its vertical position is controlled by a motor. The surface is first lowered to be in immediate contact with the polyvinylpyrrolidone (PVPY water solution with concentration from 1 to 5 wt%, then pulled at the speed of 0.004 to 0.4 mm/s. By tuning the pulling speed and concentration we can realize conformal, filled, top-only, as well as floating film morphology. For a reproducible liquid detachment from the solid, the sample has a small tilt angle of 3 degree. Contact coating is used to cover the Al grid base of the vertical space-charge-limited transistor with PVPY. Poly(3-hexylthiophene-2,5-diyl (P3HT as the semiconductor. The transistor breakdown voltage is raised due to base coverage achieved by contact coating.

  20. 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.

  1. 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

  2. Microstructure and wear behavior of {gamma}/Al{sub 4}C{sub 3}/TiC/CaF{sub 2} composite coating on {gamma}-TiAl intermetallic alloy prepared by Nd:YAG laser cladding

    Energy Technology Data Exchange (ETDEWEB)

    Liu Xiubo [School of Mechanical and Electronic Engineering, 178 Ganjiang East Road, Soochow University, Suzhou 215021 (China)], E-mail: liubobo0828@yahoo.com.cn; Shi Shihong [School of Mechanical and Electronic Engineering, 178 Ganjiang East Road, Soochow University, Suzhou 215021 (China); Guo Jian [School of Materials and Chemical Engineering, Zhongyuan Institute of Technology, 41 Zhongyuan West Road, Zhengzhou 450007 (China); Fu Geyan; Wang Mingdi [School of Mechanical and Electronic Engineering, 178 Ganjiang East Road, Soochow University, Suzhou 215021 (China)

    2009-03-15

    As a further step in obtaining high performance elevated temperature self-lubrication anti-wear composite coatings on TiAl alloy, a novel Ni-P electroless plating method was adopted to encapsulate the as-received CaF{sub 2} in the preparation of precursor NiCr-Cr{sub 3}C{sub 2}-CaF{sub 2} mixed powders with an aim to decrease its mass loss and increase its compatibility with the metal matrix during a Nd:YAG laser cladding. The microstructure of the coating was examined using X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) and the friction and wear behavior of the composite coatings sliding against the hardened 0.45% C steel ring was evaluated using a block-on-ring wear tester at room temperature. It was found that the coating had a unique microstructure consisting of primary dendrites TiC and block Al{sub 4}C{sub 3} carbides reinforcement as well as fine isolated spherical CaF{sub 2} solid lubrication particles uniformly dispersed in the NiCrAlTi ({gamma}) matrix. The good friction-reducing and anti-wear abilities of the laser clad composite coating was suggested to the Ni-P electroless plating and the attendant reduction of mass loss of CaF{sub 2} and the increasing of it's wettability with the NiCrAlTi ({gamma}) matrix during the laser cladding process.

  3. New non-stick expoxy-silicone water-based coatings part 1: Physical and surface properties

    Energy Technology Data Exchange (ETDEWEB)

    Garti, N. [Hebrew Univ. of Jerusalem (Israel); Smith, J. [Decora Manufacturing, Fort Edward, NY (United States)

    1995-06-01

    In search for tomorrow`s technology for water-based coating, Decora Manufacturing and The Hebrew University of Jerusalem, have initiated an intensive research program for designing, developing and manufacturing new coatings based on cross-linked, room temperature-cured silicone-expoxy resins. The new water-borne coatings have most exciting characteristics such as: non-stick properties, effective release, high lubricity, corrosion protection and abrasion resistance. The coatings are environmentally-friendly and easy to use. These coatings are ideal for marine, agricultural, industrial and maintenance applications. This paper brings quantitative measurements related to the dispersion technology (particle size, stability, shelf-life), to the non-stick properties (deicing, low surface energy, easy-release and non-stick), lubricity, adhesion to substrates, viscosity, dynamic and static friction coefficients and environmental impact (low VOC, non-toxicity, low-leaching). The coating was tested in various industrial coating systems and was found to exhibit excellent non-stick and release properties. Special attention was given to Zebra Mussels, Quagga Mussels and other bacterial and algeal bioforms. The coating proved to be efficient as foul-release coating with very low biofouling adhesion. The low adhesion applied to many other substances in which foul-release means easy-clean and low-wear.

  4. 77 FR 41337 - Approval and Promulgation of Air Quality Implementation Plans; Delaware; Control Technique...

    Science.gov (United States)

    2012-07-13

    ... metal lid, door, casing, panel, or other interior or exterior metal part or accessory that is assembled..., pretreatment coating, repair coating, safety-indicating coating, solar- absorbent coating, solid-film lubricant....5 Metallic 0.420 3.5 0.420 3.5 Pretreatment 0.420 3.5 0.420 3.5 Solar-absorbent 0.360 3.0 0.420 3.5...

  5. 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.

  6. PEG-stearate coated solid lipid nanoparticles as levothyroxine carriers for oral administration

    Science.gov (United States)

    Kashanian, Soheila; Rostami, Elham

    2014-03-01

    In this study, poly ethylene glycol 100 stearate (PEG 100-S) was used to prepare coated solid lipid nanoparticles with loading levothyroxine sodium (levo-loaded PEG 100-S-coated SLNs) by microemulsification technique. Evaluation of the release kinetic of prepared colloidal carriers was conducted. The particle size and zeta potential of levo-loaded PEG 100-S-coated SLNs have been measured to be 187.5 nm and -23.0 mV, respectively, using photon correlation spectroscopy (PCS). Drug entrapment efficiency (EE) was calculated to be 99 %. Differential scanning calorimetry indicated that the majority of drug loaded in PEG 100-S-coated SLNs were in amorphous state which could be considered desirable for drug delivery. The purpose of this study was to develop a new nanoparticle system, consisting lipid nanoparticles coated with PEG 100-S. The modification procedure led to a reduction in the zeta potential values, varying from -40.0 to -23.0 mV for the uncoated and PEG-coated SLNs, respectively. Stability results of the nanoparticles in gastric and intestinal media show that the low pH of the gastric medium is responsible for the critical aggregation and degradation of the uncoated lipid nanoparticles. PEG 100-S-coated SLNs were more stable due to their polymer coating layer which prevented aggregation of SLNs. Consequently, it is possible that the PEG surrounds the particles reducing the attachment of enzymes and further degradation of the triglyceride cores. Shape and surface morphology of particles were determined by transition electron microscopy and scanning electron microscopy that revealed spherical shape of nanoparticles. In vitro drug release of PEG 100-S-coated SLNs was characterized using diffusion cell which showed a controlled release for drug.

  7. Does the conductivity of interconnect coatings matter for solid oxide fuel cell applications?

    Science.gov (United States)

    Goebel, Claudia; Fefekos, Alexander G.; Svensson, Jan-Erik; Froitzheim, Jan

    2018-04-01

    The present work aims to quantify the influence of typical interconnect coatings used for solid oxide fuel cells (SOFC) on area specific resistance (ASR). To quantify the effect of the coating, the dependency of coating thickness on the ASR is examined on Crofer 22 APU at 600 °C. Three different Co coating thicknesses are investigated, 600 nm, 1500 nm, and 3000 nm. Except for the reference samples, the material is pre-oxidized prior to coating to mitigate the outward diffusion of iron and consequent formation of poorly conducting (Co,Fe)3O4 spinel. Exposures are carried out at 600 °C in stagnant laboratory air for 500 h and subsequent ASR measurements are performed. Additionally the microstructure is investigated with scanning electron microscopy (SEM). On all pre-oxidized samples, a homogenous dense Co3O4 top layer is observed beneath which a thin layer of Cr2O3 is present. As the ASR values range between 7 and 12 mΩcm2 for all pre-oxidized samples, even though different Co3O4 thicknesses are observed, the results strongly suggest that for most applicable cases the impact of the coating on ASR is negligible and the main contributor is Cr2O3.

  8. Salt-Driven Deposition of Thermoresponsive Polymer-Coated Metal Nanoparticles on Solid Substrates.

    Science.gov (United States)

    Zhang, Zhiyue; Maji, Samarendra; da Fonseca Antunes, André B; De Rycke, Riet; Hoogenboom, Richard; De Geest, Bruno G

    2016-06-13

    Here we report on a simple, generally applicable method for depositing metal nanoparticles on a wide variety of solid surfaces under all aqueous conditions. Noble-metal nanoparticles obtained by citrate reduction followed by coating with thermoresponsive polymers spontaneously form a monolayer-like structure on a wide variety of substrates in presence of sodium chloride whereas this phenomenon does not occur in salt-free medium. Interestingly, this phenomenon occurs below the cloud point temperature of the polymers and we hypothesize that salt ion-induced screening of electrostatic charges on the nanoparticle surface entropically favors hydrophobic association between the polymer-coated nanoparticles and a hydrophobic substrate. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. 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.

  10. Wear behaviour of wear-resistant adaptive nano-multilayered Ti-Al-Mo-N coatings

    Science.gov (United States)

    Sergevnin, V. S.; Blinkov, I. V.; Volkhonskii, A. O.; Belov, D. S.; Kuznetsov, D. V.; Gorshenkov, M. V.; Skryleva, E. A.

    2016-12-01

    Coating samples in the Ti-Al-Mo-N system were obtained by arc-PVD method at variable bias voltage Ub applied to the substrate, and the partial pressure of nitrogen P(N2) used as a reaction gas. The deposited coatings were characterized by a nanocrystalline structure with an average grain size of 30-40 nm and multilayered architecture with alternating layers of (Ti,Al)N nitride and Mo-containing phases with a thickness comparable to the grain size. Coatings of (Ti,Al)N-Mo-Mo2N and (Ti,Al)N-Mo2N compositions were obtained by changing deposition parameters. The obtained coatings had hardness of 40 GPa and the relative plastic deformation under microindentation up to 60%. (Ti,Al)N-Mo2N coatings demonstrated better physicomechanical characteristics, showing high resistance to crack formation and destruction through the plastic deformation mechanism without brittle fracturing, unlike (Ti,Al)N-Mo-Mo2N. The friction coefficient of the study coatings (against Al2O3 balls under dry condition using a pin-on-disc method) reached the values of 0.35 and 0.5 at 20 °C and 500 °C respectively, without noticeable wear within this temperature range. These tribological properties were achieved by forming MoO3 acting as a solid lubricant. At higher temperatures the deterioration in the tribological properties is due to the high rate of MoO3 sublimation from friction surfaces.

  11. 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....

  12. 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

  13. Forming of High-strength Steels Using a Hot-melt Dry Lubricant

    DEFF Research Database (Denmark)

    Hörnström, Sven-Erik; Karlsson, Erik; Olsson, Mikael

    2008-01-01

    during forming resulting in seizure of the tool/steel sheet contact and extensive scratching of the steel sheet surface. As a result, a number of concepts have been developed in order to reduce the tendency to galling in metal forming, including the development of new dry lubricants, new forming tool...... steel grades and improved surface engineering treatments such as the deposition of low friction CVD and PVD coatings. In the present study the performance of a hot-melt dry lubricant in the forming of hot and cold rolled and hot-dip galvanized high strength steel has been evaluated and compared...... with a conventional rust protection oil using four different tests methods, i.e. a strip reduction test, a bending under tension test, a stretch-forming test and a pin-on disc test. In the tests, two different cold work tool steels, a conventional steel grade and a nitrogen alloyed PM steel grade were evaluated...

  14. 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.

  15. European coatings conference - Marine coatings. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    This volume contains 13 lectures (manuscripts or powerpoint foils) with the following topics: 1. Impact of containerization on polyurethane and polyurea in marine and protective coatings (Malte Homann); 2. The application of combinatorial/high-throughput methods to the development of marine coatings (Bret Chisholm); 3. Progress and perspectives in the AMBIO (advanced nanostructured surfaces for the control of biofouling) Project (James Callow); 4. Release behaviour due to shear and pull-off of silicone coatings with a thickness gradient (James G. Kohl); 5. New liquid rheology additives for high build marine coatings (Andreas Freytag); 6. Effective corrosion protection with polyaniline, polpyrrole and polythiophene as anticorrosice additives for marine paints (Carlos Aleman); 7. Potential applications of sol gel technology for marine applications (Robert Akid); 8: Performance of biocide-free Antifouling Coatings for leisure boats (Bernd Daehne); 9. Novel biocidefree nanostructured antifouling coatings - can nano do the job? (Corne Rentrop); 10. One component high solids, VOC compliant high durability finish technology (Adrian Andrews); 11. High solid coatings - the hybrid solution (Luca Prezzi); 12. Unique organofunctional silicone resins for environmentally friendly high-performance coatings (Dieter Heldmann); 13. Silicone-alkyd paints for marine applications: from battleship-grey to green (Thomas Easton).

  16. 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.

  17. 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.

  18. Instrumental and sensory quantification of oral coatings retained after swallowing semi-solid foods

    NARCIS (Netherlands)

    Prinz, J.F.; Huntjens, L.; Wijk, de R.A.

    2006-01-01

    After a mouthful of food has been swallowed, some food material is always retained in the mouth. With semi-solid foods this is in the form of a coating that adheres to the oral mucosa. The amount and location of this material may play an important role in food sensations. In this study two

  19. A star-shaped polythiophene dendrimer coating for solid-phase microextraction of triazole agrochemicals.

    Science.gov (United States)

    Abolghasemi, Mir Mahdi; Habibiyan, Rahim; Jaymand, Mehdi; Piryaei, Marzieh

    2018-02-14

    A nanostructured star-shaped polythiophene dendrimer was prepared and used as a fiber coating for headspace solid phase microextraction of selected triazolic pesticides (tebuconazole, hexaconazole, penconazole, diniconazole, difenoconazole, triticonazole) from water samples. The dendrimer with its large surface area was characterized by thermogravimetric analysis, UV-Vis spectroscopy and field emission scanning electron microscopy. It was placed on a stainless steel wire for use in SPME. The experimental conditions for fiber coating, extraction, stirring rate, ionic strength, pH value, desorption temperature and time were optimized. Following thermal desorption, the pesticides were quantified by GC-MS. Under optimum conditions, the repeatability (RSD) for one fiber (for n = 3) ranges from 4.3 to 5.6%. The detection limits are between 8 and 12 pg mL -1 . The method is fast, inexpensive (in terms of equipment), and the fiber has high thermal stability. Graphical abstract Schematic presentation of a nanostructured star-shaped polythiophene dendrimer for use in headspace solid phase microextraction of the triazolic pesticides (tebuconazole, hexaconazole, penconazole, diniconazole, difenoconazole, triticonazole). They were then quantified by gas chromatography-mass spectrometry.

  20. 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

  1. 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

  2. Optimization of spin-coated electrodes for electrolyte-supported solid oxide fuel cells

    International Nuclear Information System (INIS)

    Nobrega, Shayenne Diniz da; Monteiro, Natalia Kondo; Tabuti, Francisco; Fonseca, Fabio Coral; Florio, Daniel Zanetti de

    2017-01-01

    Electrodes for electrolyte-supported solid oxide fuel cells (SOFC’s) were fabricated by spin coating. Strontium-doped lanthanum manganite (LSM) cathode and nickel yttria-stabilized zirconia cermet anodes were synthesized and processed for enhanced deposition conditions. The influence of electrode microstructural parameters was investigated by a systematic experimental procedure aiming at optimized electrochemical performance of single cells. Polarization curves showed a strong dependence on both electrode thickness and sintering temperature. By a systematic control of such parameters, the performance of single cells was significantly enhanced due to decreasing of polarization resistance from 26 Ω cm² to 0.6 Ω cm² at 800°C. The results showed that spin-coated electrodes can be optimized for fast and cost effective fabrication of SOFCs. (author)

  3. Optimization of spin-coated electrodes for electrolyte-supported solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Nobrega, Shayenne Diniz da; Monteiro, Natalia Kondo; Tabuti, Francisco; Fonseca, Fabio Coral, E-mail: shaynnedn@hotmail.com, E-mail: nataliakm@usp.br, E-mail: fntabuti@ipen.br, E-mail: fabiocf@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Sao Paulo, SP (Brazil); Florio, Daniel Zanetti de, E-mail: daniel.florio@ufabc.edu.br [Universidade Federal do ABC (UFABC), Santo Andre, SP (Brazil)

    2017-01-15

    Electrodes for electrolyte-supported solid oxide fuel cells (SOFC’s) were fabricated by spin coating. Strontium-doped lanthanum manganite (LSM) cathode and nickel yttria-stabilized zirconia cermet anodes were synthesized and processed for enhanced deposition conditions. The influence of electrode microstructural parameters was investigated by a systematic experimental procedure aiming at optimized electrochemical performance of single cells. Polarization curves showed a strong dependence on both electrode thickness and sintering temperature. By a systematic control of such parameters, the performance of single cells was significantly enhanced due to decreasing of polarization resistance from 26 Ω cm² to 0.6 Ω cm² at 800°C. The results showed that spin-coated electrodes can be optimized for fast and cost effective fabrication of SOFCs. (author)

  4. Non-sticky translocation of bio-molecules through Tween 20-coated solid-state nanopores in a wide pH range

    Science.gov (United States)

    Li, Xiaoqing; Hu, Rui; Li, Ji; Tong, Xin; Diao, J. J.; Yu, Dapeng; Zhao, Qing

    2016-10-01

    Nanopore-based sensing technology is considered high-throughput and low-cost for single molecule detection, but solid-state nanopores have suffered from pore clogging issues. A simple Tween 20 coating method is applied to ensure long-term (several hours) non-sticky translocation of various types of bio-molecules through SiN nanopores in a wide pH range (4.0-13.0). We also emphasize the importance of choosing appropriate concentration of Tween 20 coating buffer for desired effect. By coating nanopores with a Tween 20 layer, we are able to differentiate between single-stranded DNA and double-stranded DNA, to identify drift-dominated domain for single-stranded DNA, to estimate BSA volume and to observe the shape of individual nucleosome translocation event without non-specific adsorption. The wide pH endurance from 4.0 to 13.0 and the broad types of detection analytes including nucleic acids, proteins, and biological complexes highlight the great application potential of Tween 20-coated solid-state nanopores.

  5. 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

  6. Soft lubrication: The elastohydrodynamics of nonconforming and conforming contacts

    Science.gov (United States)

    Skotheim, J. M.; Mahadevan, L.

    2005-09-01

    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 parallel to a soft layer coating a rigid substrate; a soft cylinder moving parallel to a rigid substrate; a cylindrical shell moving parallel to a rigid substrate; and finally a cylindrical conforming journal bearing coated with a thin soft layer. In addition, for the particular case of a soft layer coating a rigid substrate, we consider both elastic and poroelastic material responses. 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 parameter η =hydrodynamicpressure/elasticstiffness=surfacedeflection/gapthickness, which characterizes the fluid-induced deformation of the interface. The corresponding cases for a spherical slider are treated using scaling concepts.

  7. Feasibility of bovine submaxillary mucin (BSM) films as biomimetic coating for polymeric biomaterials

    DEFF Research Database (Denmark)

    Lee, Seunghwan; Madsen, Jan Busk; Pakkanen, Kirsi I.

    2013-01-01

    Feasibility of bovine submaxillary mucin (BSM) films generated via spontaneous adsorption from aqueous solutions onto polydimethylsiloxane (PDMS) and polystyrene (PS) surfaces have been investigated as biomimetic coatings for polymeric biomaterials. Two attributes as biomedical coatings, namely a......-on-disk tribometry, employing compliant PDMS as tribopairs, has shown that BSM coatings generated on PDMS surface via spontaneous adsorption from aqueous solution has effective lubricating properties, but for very limited duration only....

  8. Urinary catheter with polyurethane coating modified by ion implantation

    International Nuclear Information System (INIS)

    Kondyurina, I.; Nechitailo, G.S.; Svistkov, A.L.; Kondyurin, A.; Bilek, M.

    2015-01-01

    A low friction urinary catheter that could be used without a lubricant is proposed in this work. A polyurethane coating was synthesised on the surface of a metal guide wire catheter. Ion implantation was applied to surface modify the polyurethane coating. FTIR ATR, wetting angle, AFM and friction tests were used for analysis. Low friction was found to be provided by the formation of a hard carbonised layer on the polyurethane surface

  9. Tribological properties of epoxy composite coatings reinforced with functionalized C-BN and H-BN nanofillers

    Science.gov (United States)

    Yu, Jingjing; Zhao, Wenjie; Wu, Yinghao; Wang, Deliang; Feng, Ruotao

    2018-03-01

    A series of epoxy resin (EP) composite coatings reinforced with functionalized cubic boron nitride (FC-BN) and functionalized hexagonal boron nitride (FH-BN) were fabricated successfully on 316L stainless steel by hand lay-up technique. The structure properties were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The morphologies were characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Moreover, UMT-3 tribometer and surface profiler were used to investigate tribological behaviors of as-prepared composite coatings under dry friction and seawater conditions respectively. The results demonstrated that the presence of FC-BN or FH-BN fillers could greatly decrease the friction coefficient (COF) and wear rate of epoxy, in addition, composite coatings possess better tribological properties under seawater condition which was attributed to the lubricating effect of seawater. Moreover, FC-BN endows the composite coatings the highest wear resistance, and FH-BN /EP composite coatings exhibited the best friction reduction performance which is attributed to the self-lubricating performance of lamella structure for FH-BN sheet.

  10. 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

  11. 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)

  12. 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.

  13. 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.

  14. Effect of coating density on oxidation resistance and Cr vaporization from solid oxide fuel cell interconnects

    Science.gov (United States)

    Talic, Belma; Falk-Windisch, Hannes; Venkatachalam, Vinothini; Hendriksen, Peter Vang; Wiik, Kjell; Lein, Hilde Lea

    2017-06-01

    Manganese cobalt spinel oxides are promising materials for protective coatings for solid oxide fuel cell (SOFC) interconnects. To achieve high density such coatings are often sintered in a two-step procedure, involving heat treatment first in reducing and then in oxidizing atmospheres. Sintering the coating inside the SOFC stack during heating would reduce production costs, but may result in a lower coating density. The importance of coating density is here assessed by characterization of the oxidation kinetics and Cr evaporation of Crofer 22 APU with MnCo1.7Fe0.3O4 spinel coatings of different density. The coating density is shown to have minor influence on the long-term oxidation behavior in air at 800 °C, evaluated over 5000 h. Sintering the spinel coating in air at 900 °C, equivalent to an in-situ heat treatment, leads to an 88% reduction of the Cr evaporation rate of Crofer 22 APU in air-3% H2O at 800 °C. The air sintered spinel coating is initially highly porous, however, densifies with time in interaction with the alloy. A two-step reduction and re-oxidation heat treatment results in a denser coating, which reduces Cr evaporation by 97%.

  15. 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.

  16. 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.

  17. 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 ...

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. Wear studies on ZrO2-filled PEEK as coating bearing materials for artificial cervical discs of Ti6Al4V

    International Nuclear Information System (INIS)

    Song, Jian; Liu, Yuhong; Liao, Zhenhua; Wang, Song; Tyagi, Rajnesh; Liu, Weiqiang

    2016-01-01

    Polyetheretherketone (PEEK) and its composite coatings are believed to be the potential candidates' bio-implant materials. However, these coatings have not yet been used on the surface of titanium-based orthopedics and joint products and very few investigations on the tribological characteristics could be found in the published literature till date. In this study, the wettabilities, composition and micro-hardness were characterized using contact angle measurement, scanning electron microscopy (SEM) and hardness tester. The tribological tests were conducted using a ball-on-disc contact pair under 25% newborn calf serum (NCS) lubricated condition. For comparison, bare Ti6Al4V was studied. The obtained results revealed that those PEEK/ZrO 2 composite coatings could improve the tribological properties of Ti6Al4V significantly. Adhesive wear and mild abrasive wear might be the dominant wear and failure mechanisms for PEEK/ZrO 2 composite coatings in NCS lubricated condition. After comprehensive evaluation in the present study, 5 wt.% ZrO 2 nanoparticles filled PEEK coating displayed the optimum tribological characteristics and could be taken as a potential candidate for the bearing material of artificial cervical disc. - Graphical abstract: Polyetheretherketone (PEEK) is a type of biomaterial which might be used in surface modification. In this study, the wettabilities, composition, hardness, friction and wear characteristics of PEEK/ZrO 2 coatings were investigated, compared with bare Ti6Al4V sample. After comprehensive evaluation, 5 wt.% ZrO 2 nanoparticles filled PEEK coating displayed the optimum tribological characteristics and could be taken as a potential candidate for the bearing material of artificial cervical disc. - Highlights: • PEEK coating were filled by ZrO 2 nanoparticles with different weight percentage. • The lubrication regime of all the tested samples are boundary lubrication. • Adhesive wear and mild abrasive wear were the dominant wear

  3. Contribution of surface analysis spectroscopic methods to the lubrication field

    International Nuclear Information System (INIS)

    Blanc, C.

    1979-01-01

    The analytical surface technics such as ESCA, AES and SIMS are tested to be applied to a particular lubrication field. One deals with a 100 C 6 steel surface innumered in tricresylphosphate at 110 0 C for 15 days. The nature of the first layers is studied after relevant solvant cleaning. An iron oxide layer is produced on the bearing surface, namely αFe 2 -O 3 . ESCA, AES and SIMS studies show an overlayer of iron phosphate. The exact nature of iron phosphate is not clearly established but the formation of a ferrous phosphate coating can be assumed from ESCA analysis [fr

  4. Anodized porous titanium coated with Ni-CeO{sub 2} deposits for enhancing surface toughness and wear resistance

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Xiaowei, E-mail: zhouxiaowei901@163.com; Ouyang, Chun

    2017-05-31

    Highlights: • Structural design of anodized nanoporous Ti was introduced for bonding pinholes to achieve a metallurgical bonding interface. • Anodized porous Ti substrate was activated by electroless Ni-P film to be acted as transitional layer to deposit Ni-CeO{sub 2} nanocomposite coatings. • An analytical model was validated for predicting the Ce-rich worn products as a self-lubricant phase for monitoring wear mechanisms. - Abstract: In order to make large improvements of surface toughness and wear resistance for pure titanium (Ti) substrate, anodic titanium oxide (ATO) surface with nanoporous structure was coated with the Ni-CeO{sub 2} nanocomposite coatings. Regarding TiO{sub 2} barrier layer on Ti surface to inhibit its electrochemical activity, pre-treatments were successively processed with anodizing, sensitizing, activating, and then followed by electroless Ni-P film to be acted as an activated layer for electroplating Ni-CeO{sub 2} deposits. The existing Pd atoms around ATO nanopores were expected as the heterogeneous nucleation sites for supporting the growing locations of electroless Ni-P film. The innovative of interface design using porous structure was introduced for bonding pinholes to achieve a metallurgical adhesion interface between Ti substrate and surface coatings. Besides the objectives of this work were to elucidate how effects by the adding CeO{sub 2} nanoparticles on modifying microstructures and wear mechanisms of Ni-CeO{sub 2} nanocomposite coatings. Many efforts of XRD, FE-SEM, TEM and Nanoindentation tests were devoted to comparing different wear behaviors of Ni-CeO{sub 2} coatings relative to pure nickel. Results indicated that uniform-distributed Ti nanopores with an average diameter size of ∼200 nm was achieved using the Phosphate-type anodizing solution at DC 150 V. A worn surface without fatigue cracks was observed for TAO surface coated with Ni-CeO{sub 2} deposits, showing the existing Ce-rich worn products to be acted as a

  5. 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.

  6. 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...

  7. 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...

  8. Alendronate Sodium as Enteric Coated Solid Lipid Nanoparticles; Preparation, Optimization, and In Vivo Evaluation to Enhance Its Oral Bioavailability.

    Directory of Open Access Journals (Sweden)

    Khaled Mohamed Hosny

    Full Text Available Treatment of osteoporosis with alendronate sodium has several challenges. The first challenge is the low bioavailability. The second main challenge is side effects, which include oesophageal ulceration. The aim of this research was to reformulate alendronate sodium as enteric coated solid lipid nanoparticles in order to enhance its bioavailability, and preventing the free alendronate sodium from coming into direct contact with the gastrointestinal mucosa, and thereby reducing the possibility of side effects. Enteric coated solid lipid nanoparticles were prepared according to the Box-Behnken design employing Design expert® software, and characterized for size, morphology, and entrapment efficiency. The optimized formula was coated with an Eudragit S100 and evaluated for drug release in acidic and basic media, stability studies and pharmacokinetic evaluations on rabbits. The results indicated that, using Derringer's desirability functional tool for optimization, the highest entrapment efficiency value of 74.3% and the smallest size value of 98 nm were predicted under optimum conditions with a desirability value of 0.917. The optimized nanoparticles released alendronate sodium only at an alkaline pH. The pharmacokinetic evaluation revealed that alendronate sodium bioavailability was enhanced by more than 7.4-fold in rabbits. In conclusion, enteric coated solid lipid nanoparticles is a promising formula for the delivery of alendronate sodium, eliminating its oesophageal side effects and enhancing its bioavailability.

  9. Expanding the Applicability of Poly(Ionic Liquids in Solid Phase Microextraction: Pyrrolidinium Coatings

    Directory of Open Access Journals (Sweden)

    David J. S. Patinha

    2017-09-01

    Full Text Available Crosslinked pyrrolidinium-based poly(ionic liquids (Pyrr-PILs were synthesized through a fast, simple, and solventless photopolymerization scheme, and tested as solid phase microextraction (SPME sorbents. A series of Pyrr-PILs bearing three different alkyl side chain lengths with two, eight, and fourteen carbons was prepared, characterized, and homogeneously coated on a steel wire by using a very simple procedure. The resulting coatings showed a high thermal stability, with decomposition temperatures above 350 °C, excellent film stability, and lifetime of over 100 injections. The performance of these PIL-based SPME fibers was evaluated using a mixture of eleven organic compounds with different molar volumes and chemical functionalities (alcohols, ketones, and monoterpenes. The Pyrr-PIL fibers were obtained as dense film coatings, with 67 μm thickness, with an overall sorption increase of 90% and 55% as compared to commercial fibers of Polyacrylate (85 μm (PA85 and Polydimethylsiloxane (7 μm (PDMS7 coatings, respectively. A urine sample doped with the sample mixture was used to study the matrix effect and establish relative recoveries, which ranged from 60.2% to 104.1%.

  10. 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.

  11. 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

  12. Wear studies on ZrO{sub 2}-filled PEEK as coating bearing materials for artificial cervical discs of Ti6Al4V

    Energy Technology Data Exchange (ETDEWEB)

    Song, Jian [State Key Laboratory of Tribology, Tsinghua University, Beijing 100084 (China); Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China); Liu, Yuhong, E-mail: liuyuhong@tsinghua.edu.cn [State Key Laboratory of Tribology, Tsinghua University, Beijing 100084 (China); Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China); Liao, Zhenhua; Wang, Song [Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China); Biomechanics and Biotechnology Lab, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057 (China); Tyagi, Rajnesh [Department of Mechanical Engineering, Indian Institute of Technology (BHU) Varanasi, Varanasi 221005 (India); Liu, Weiqiang, E-mail: weiqliu@hotmail.com [State Key Laboratory of Tribology, Tsinghua University, Beijing 100084 (China); Biomechanics and Biotechnology Lab, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057 (China)

    2016-12-01

    Polyetheretherketone (PEEK) and its composite coatings are believed to be the potential candidates' bio-implant materials. However, these coatings have not yet been used on the surface of titanium-based orthopedics and joint products and very few investigations on the tribological characteristics could be found in the published literature till date. In this study, the wettabilities, composition and micro-hardness were characterized using contact angle measurement, scanning electron microscopy (SEM) and hardness tester. The tribological tests were conducted using a ball-on-disc contact pair under 25% newborn calf serum (NCS) lubricated condition. For comparison, bare Ti6Al4V was studied. The obtained results revealed that those PEEK/ZrO{sub 2} composite coatings could improve the tribological properties of Ti6Al4V significantly. Adhesive wear and mild abrasive wear might be the dominant wear and failure mechanisms for PEEK/ZrO{sub 2} composite coatings in NCS lubricated condition. After comprehensive evaluation in the present study, 5 wt.% ZrO{sub 2} nanoparticles filled PEEK coating displayed the optimum tribological characteristics and could be taken as a potential candidate for the bearing material of artificial cervical disc. - Graphical abstract: Polyetheretherketone (PEEK) is a type of biomaterial which might be used in surface modification. In this study, the wettabilities, composition, hardness, friction and wear characteristics of PEEK/ZrO{sub 2} coatings were investigated, compared with bare Ti6Al4V sample. After comprehensive evaluation, 5 wt.% ZrO{sub 2} nanoparticles filled PEEK coating displayed the optimum tribological characteristics and could be taken as a potential candidate for the bearing material of artificial cervical disc. - Highlights: • PEEK coating were filled by ZrO{sub 2} nanoparticles with different weight percentage. • The lubrication regime of all the tested samples are boundary lubrication. • Adhesive wear and mild abrasive

  13. 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.

  14. 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...

  15. Tribochemistry and Wear Life Improvement in Liquid-Lubricated H-DLC-Coated Bearings

    National Research Council Canada - National Science Library

    Lince, J. R; Kim, H. I; Bertrand, P. A; Eryilmaz, O. L; Erdemir, A

    2007-01-01

    In contrast to typical DLC coatings, hydrogenated DLC (H-DLC) coatings exhibit extremely low friction in vacuum and dry atmospheres, suggesting their potential importance for spacecraft applications...

  16. 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

  17. 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

  18. 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.

  19. Microstructure and Wear Behavior of FeCoCrNiMo0.2 High Entropy Coatings Prepared by Air Plasma Spray and the High Velocity Oxy-Fuel Spray Processes

    Directory of Open Access Journals (Sweden)

    Tianchen Li

    2017-09-01

    Full Text Available In the present research, the spherical FeCoCrNiMo0.2 high entropy alloy (HEA powders with a single FCC solid solution structure were prepared by gas atomization. Subsequently, the FeCoCrNiMo0.2 coatings with a different content of oxide inclusions were prepared by air plasma spraying (APS and high-velocity oxy-fuel spraying (HVOF, respectively. The microstructure, phase composition, mechanical properties, and tribological behaviors of these HEA coatings were investigated. The results showed that both HEA coatings showed a typical lamellar structure with low porosity. Besides the primary FCC phase, a mixture of Fe2O3, Fe3O4, and AB2O4 (A = Fe, Co, Ni, and B = Fe, Cr was identified as the oxide inclusions. The oxide content of the APS coating and HVOF coating was calculated to be 47.0% and 12.7%, respectively. The wear resistance of the APS coating was approximately one order of magnitude higher than that of the HVOF coating. It was mainly attributed to the self-lubricated effect caused by the oxide films. The mass loss of the APS coating was mainly ascribed to the breakaway of the oxide film, while the main wear mechanism of the HVOF coating was the abrasive wear.

  20. Study on Modified Water Glass Used in High Temperature Protective Glass Coating for Ti-6Al-4V Titanium Alloy

    Directory of Open Access Journals (Sweden)

    Shuang Yang

    2018-04-01

    Full Text Available Sodium silicate water glass was modified with sodium polyacrylate as the binder, the composite slurry used for high-temperature oxidation-resistant coating was prepared by mixing glass powder with good lubrication properties in the binder. The properties of the modified binder and high-temperature oxidation resistance of Ti-6Al-4V titanium alloy coated with composite glass coating were studied by XRD, SEM, EDS, TG-DSC and so on. Results showed that sodium polyacrylate modified water glass could obviously improve the suspension stability of the binder, the pyrolytic carbon in the binder at high temperature could increase the surface tension in the molten glass system, and the composite glass coating could be smooth and dense after heating. Pyrolytic carbon diffused and combined with oxygen in the coating under the heating process to protect the titanium alloy from oxidation. The thickness of the oxide layer was reduced 51% after applying the high-temperature oxidation-resistant coating. The coating also showed a nearly 30% reduction in friction coefficient due to the boundary lubricant regime. During cooling, the coating could be peeled off easily because of the mismatched CTE between the coating and substrate.

  1. 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

  2. Armor systems including coated core materials

    Science.gov (United States)

    Chu, Henry S [Idaho Falls, ID; Lillo, Thomas M [Idaho Falls, ID; McHugh, Kevin M [Idaho Falls, ID

    2012-07-31

    An armor system and method involves providing a core material and a stream of atomized coating material that comprises a liquid fraction and a solid fraction. An initial layer is deposited on the core material by positioning the core material in the stream of atomized coating material wherein the solid fraction of the stream of atomized coating material is less than the liquid fraction of the stream of atomized coating material on a weight basis. An outer layer is then deposited on the initial layer by positioning the core material in the stream of atomized coating material wherein the solid fraction of the stream of atomized coating material is greater than the liquid fraction of the stream of atomized coating material on a weight basis.

  3. Testing Cadmium-Free Coatings

    Science.gov (United States)

    2011-08-30

    Secretary of Defense Directive • “Approve the use of alternatives [to hexavalent chromium (Cr6+)] where they can perform adequately for the intended...Effect of corrosion on breakaway torque 12 OPSEC approved for public release Fastener Finish Study FINISH POST-TREATMENT LUBRICANT Cadmium Hexavalent ...Past Testing Electrical Connectors Coatings Al / TCP ZnNi / TCP ZnNi / Non- Chrome Passivation (NCP) Ni-PTFE 1 Ni-PTFE 2 Note: SnZn tested on flat

  4. Vanadium carbide coatings: deposition process and properties

    International Nuclear Information System (INIS)

    Borisova, A.; Borisov, Y.; Shavlovsky, E.; Mits, I.; Castermans, L.; Jongbloed, R.

    2001-01-01

    Vanadium carbide coatings on carbon and alloyed steels were produced by the method of diffusion saturation from the borax melt. Thickness of the vanadium carbide layer was 5-15 μm, depending upon the steel grade and diffusion saturation parameters. Microhardness was 20000-28000 MPa and wear resistance of the coatings under conditions of end face friction without lubrication against a mating body of WC-2Co was 15-20 times as high as that of boride coatings. Vanadium carbide coatings can operate in air at a temperature of up to 400 o C. They improve fatigue strength of carbon steels and decrease the rate of corrosion in sea and fresh water and in acid solutions. The use of vanadium carbide coatings for hardening of various types of tools, including cutting tools, allows their service life to be extended by a factor of 3 to 30. (author)

  5. 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.

  6. 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....

  7. 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

  8. 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

  9. Numerical analysis of micro-/nanoscale gas-film lubrication of sliding surface with complicated structure

    International Nuclear Information System (INIS)

    Kawagoe, Yoshiaki; Isono, Susumu; Takeno, Takanori; Yonemura, Shigeru; Takagi, Toshiyuki; Miki, Hiroyuki

    2014-01-01

    It has been reported that the friction between a partially polished diamond-coated surface and a metal surface was drastically reduced to zero when they are slid at a few m/s. Since the sliding was noiseless, it seems that the diamond-coated surface was levitated over the counter surface and the sliding mechanism was the gas film lubrication. Recently, the mechanism of levitation of a slider with a micro/nanoscale surface structure on a rotating disk was theoretically clarified [S. Yonemura et al., Tribol. Lett., (2014), doi:10.1007/s11249-014-0368-2]. Probably, the partially polished diamond-coated surface may be levitated by high gas pressure generated by the micro/nanoscale surface structure on it. In this study, in order to verify our deduction, we performed numerical simulations of sliding of partially polished diamond-coated surface by reproducing its complicated surface structure using the data measured by an atomic force microscope (AFM). As a result, we obtained the lift force which is large enough to levitate the slider used in the experiment

  10. Numerical analysis of micro-/nanoscale gas-film lubrication of sliding surface with complicated structure

    Energy Technology Data Exchange (ETDEWEB)

    Kawagoe, Yoshiaki; Isono, Susumu; Takeno, Takanori [Department of Nanomechanics, Graduate School of Engineering, Tohoku University, 6-6-01 Aoba, Aramaki, Aoba-ku, Sendai 980-8579 (Japan); Yonemura, Shigeru; Takagi, Toshiyuki [Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Miki, Hiroyuki [Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai 980-8578 (Japan)

    2014-12-09

    It has been reported that the friction between a partially polished diamond-coated surface and a metal surface was drastically reduced to zero when they are slid at a few m/s. Since the sliding was noiseless, it seems that the diamond-coated surface was levitated over the counter surface and the sliding mechanism was the gas film lubrication. Recently, the mechanism of levitation of a slider with a micro/nanoscale surface structure on a rotating disk was theoretically clarified [S. Yonemura et al., Tribol. Lett., (2014), doi:10.1007/s11249-014-0368-2]. Probably, the partially polished diamond-coated surface may be levitated by high gas pressure generated by the micro/nanoscale surface structure on it. In this study, in order to verify our deduction, we performed numerical simulations of sliding of partially polished diamond-coated surface by reproducing its complicated surface structure using the data measured by an atomic force microscope (AFM). As a result, we obtained the lift force which is large enough to levitate the slider used in the experiment.

  11. XPS investigations of tribofilms formed on CrN coatings

    Energy Technology Data Exchange (ETDEWEB)

    Mandrino, Djordje, E-mail: djordje.mandrino@imt.si; Podgornik, Bojan

    2017-02-28

    Highlights: • Formation of tribofilms from lubricant additives on CrN surfaces during tribological contact confirmed by XPS. • Chemistry & chemical state of tribofilms obtained by XPS. • Thin sulphate film forms at the top of sulphide tribofilm. • Final type of sulphide in tribolayer depends on additive chemistry and testing temperature. - Abstract: Action of lubrication additives in the case of uncoated steel surfaces, including the type and mechanism of tribofilm formation is well known and understood. However, contact type of tribofilms which might form under the tribological contact between CrN coated surfaces, remains more or less unexplored. The aim of this investigation was to study the type of tribofilms formed on the CrN coated steel samples subjected to lubricated reciprocating sliding contact under different contact conditions Contact surface and tribofilms formed were studied by X-ray Photoelectron Spectroscopy (XPS). Sample surfaces were first imaged by Scanning Electron Microscopy (SEM) to determine areas of tribofilm formation as well as areas not affected by tribological contact. In these areas survey and high resolution (HR) XPS measurements were performed to obtain information about surface chemistry and oxidation states of the constituent elements. It was found that differences between different samples, observed by the XPS measurements, may reflect differences in chemistry of tribofilms formed under different contact conditions.

  12. 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.

  13. 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.

  14. Possible alternatives to critical elements in coatings for extreme applications

    Science.gov (United States)

    Grilli, Maria Luisa; Valerini, Daniele; Piticescu, Radu Robert; Bellezze, Tiziano; Yilmaz, Mehmet; Rinaldi, Antonio; Cuesta-López, Santiago; Rizzo, Antonella

    2018-03-01

    Surface functionalisation and protection have been used since a long time for improving specific properties of materials such as lubrication, water repellence, brightness, and for increasing durability of objects and tools. Among the different kinds of surface treatments used to achieve the required properties, the use of coatings is fundamental to guarantee substrate durability in harsh environments. Extreme working conditions of temperature, pressure, irradiation, wear and corrosion occur in several applications, thus very often requiring bulk material protection by means of coatings. In this study, three main classes of coatings used in extreme conditions are considered: i) hard and superhard coatings for application in machining tools, ii) coatings for high temperatures (thermal barrier coatings), and iii) coatings against corrosion. The presence of critical elements in such coatings (Cr, Y, W, Co, etc.) is analysed and the possibility to use CRMs-free substitutes is reviewed. The role of multilayers and nanocomposites in tailoring coating performances is also discussed for thermal barrier and superhard coatings.

  15. 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.

  16. 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.

  17. 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.

  18. Rational coating of Li7P3S11 solid electrolyte on MoS2 electrode for all-solid-state lithium ion batteries

    Science.gov (United States)

    Xu, R. C.; Wang, X. L.; Zhang, S. Z.; Xia, Y.; Xia, X. H.; Wu, J. B.; Tu, J. P.

    2018-01-01

    Large interfacial resistance between electrode and electrolyte limits the development of high-performance all-solid-state batteries. Herein we report a uniform coating of Li7P3S11 solid electrolyte on MoS2 to form a MoS2/Li7P3S11 composite electrode for all-solid-state lithium ion batteries. The as-synthesized Li7P3S11 processes a high ionic of 2.0 mS cm-1 at room temperature. Due to homogeneous union and reduced interfacial resistance, the assembled all-solid-state batteries with the MoS2/Li7P3S11 composite electrode exhibit higher reversible capacity of 547.1 mAh g-1 at 0.1 C and better cycling stability than the counterpart based on untreated MoS2. Our study provides a new reference for design/fabrication of advanced electrode materials for high-performance all-solid-state batteries.

  19. 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.

  20. Layer-by-layer fabrication of chemical-bonded graphene coating for solid-phase microextraction.

    Science.gov (United States)

    Zhang, Suling; Du, Zhuo; Li, Gongke

    2011-10-01

    A new fabrication strategy of the graphene-coated solid-phase microextraction (SPME) fiber is developed. Graphite oxide was first used as starting coating material that covalently bonded to the fused-silica substrate using 3-aminopropyltriethoxysilane (APTES) as cross-linking agent and subsequently deoxidized by hydrazine to give the graphene coating in situ. The chemical bonding between graphene and the silica fiber improve its chemical stability, and the obtained fiber was stable enough for more than 150 replicate extraction cycles. The graphene coating was wrinkled and folded, like the morphology of the rough tree bark. Its performance is tested by headspace (HS) SPME of polycyclic aromatic hydrocarbons (PAHs) followed by GC/MS analysis. The results showed that the graphene-coated fiber exhibited higher enrichment factors (EFs) from 2-fold for naphthalene to 17-fold for B(b)FL as compared to the commercial polydimethylsioxane (PDMS) fiber, and the EFs increased with the number of condensed rings of PAHs. The strong adsorption affinity was believed to be mostly due to the dominant role of π-π stacking interaction and hydrophobic effect, according to the results of selectivity study for a variety of organic compounds including PAHs, the aromatic compounds with different substituent groups, and some aliphatic hydrocarbons. For PAHs analysis, the graphene-coated fiber showed good precision (<11%), low detection limits (1.52-2.72 ng/L), and wide linearity (5-500 ng/L) under the optimized conditions. The repeatability of fiber-to-fiber was 4.0-10.8%. The method was applied to simultaneous analysis of eight PAHs with satisfactory recoveries, which were 84-102% for water samples and 72-95% for soil samples, respectively.

  1. 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...

  2. Cellulose nanofibers use in coated paper

    Science.gov (United States)

    Richmond, Finley

    Cellulose Nanofibers (CNF) are materials that can be obtained by the mechanical breakdown of natural fibers. CNF have the potential to be produced at low cost in a paper mill and may provide novel properties to paper, paper coatings, paints, or other products. However, suspensions have a complex rheology even at low solid contents. To be able to coat, pump, or mix CNF at moderate solids, it is critical to understand the rheology of these suspensions and how they flow in process equipment; current papers only report the rheology up to 6% solids. Few publications are available that describe the coating of CNF onto paper or the use of CNF as an additive into a paper coating. The rheology of CNF suspensions and coatings that contain CNF were characterized with parallel-disk geometry in a controlled stress rheometer. The steady shear viscosity, the complex viscosity, the storage modulus, and the yield stress were determined for the range of solids or concentrations (2.5-10.5%). CNF were coated onto paper with a laboratory rod coater, a size press and a high speed cylindrical laboratory coater (CLC). For each case, the coat weights were measures and the properties of the papers were characterized. CNF water base suspension was found to be a shear thinning with a power law index of around 0.1. Oscillatory tests showed a linear viscoelastic region at low strains and significant storage and loss moduli even at low solids. The Cox Merz rule does not hold for CNF suspensions or coating formulations that contain CNF with complex viscosities that are about 100 times larger than the steady shear viscosities. Paper coating formulations that contain CNF were found to have viscosities and storage and loss moduli that are over ten times larger than coatings that contain starch at similar solids. CNF suspensions were coated on papers with low amount transferred on paper either at high solids or high nip loadings. The amount transferred appears to be controlled by an interaction of

  3. 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.

  4. 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

  5. Tribological Properties of Ti(Al,O)/Al2O3 Composite Coating by Thermal Spraying

    Science.gov (United States)

    Salman, Asma; Gabbitas, Brian; Cao, Peng; Zhang, Deliang

    The use of thermal spray coatings provides protection to the surfaces operating in severe environments. The main goal of the current work is to investigate the possibility of using a high velocity air fuel (HVAF) thermally sprayed wear resistant Ti(Al,O)/Al2O3 coating on tool steel (H13) which is used for making dies for aluminium high pressure die casting and dummy blocks aluminium extrusion. A feedstock of Ti(Al,O)/Al2O3 composite powder was produced from a mixture of Al and TiO2 powders by high energy mechanical milling, followed by a thermal reaction process. The feedstock was then thermally sprayed using a high velocity air-fuel (HVAF) technique onto H13 steel substrates to produce a composite coating. The present study describes and compares the tribological properties such as friction and sliding wear rate of the coating both at room and high temperature (700°C). The wear resistance of the coating was investigated by a tribometer using a spherical ended alumina pin as a counter body under dry and lubricating conditions. The results showed that composite coating has lower wear rate at high temperature than at room temperature without using lubricant. The composite coating was characterized using scanning electron microscopy (SEM), optical microscopy and X-ray diffractometry (XRD). This paper reports the experimental observations and discusses the wear resistance performance of the coatings at room and high temperatures.

  6. Controlling the Accumulation of Water at Oil-Solid Interfaces with Gradient Coating.

    Science.gov (United States)

    Li, Yan; Yang, Qiaomu; Mei, Ran Andy; Cai, Meirong; Heng, Jerry Y Y; Yang, Zhongqiang

    2017-07-13

    In this work, we demonstrate a strategy to control the accumulation of water in the oil-solid interface using a gradient coating. Gradient chemistry on glass surface is created by vapor diffusion of organosilanes, leading to a range of contact angles from 110 to 20°. Hexadecane is placed on the gradient substrate as an oil layer, forming a "water/hexadecane/gradient solid substrate" sandwich structure. During incubation, water molecules spontaneously migrate through the micrometer-thick oil layer and result in the formation of micrometer-sized water droplets at the oil-solid interface. It turns out that water droplets at more hydrophobic regions tend to be closer to a regular spherical shape, which is attributed to their higher contact angle with the hydrophobic substrate. However, along the gradient from hydrophobic to hydrophilic, the water droplets gradually form more irregular shapes, as hydrophilic surfaces pin the edges of droplets to form a distorted morphology. It indicates that more hydrophilic surfaces containing more Si-OH groups lead to a higher electrostatic interaction with water and a higher growth rate of interfacial water droplets. This work provides further insights into the mechanism of spontaneous water accumulation at oil-solid interfaces and assists in the rational design for controlling such interfacial phenomenon.

  7. 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)

  8. 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...

  9. 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...

  10. 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  

  11. 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.

  12. 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.

  13. 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...

  14. Aqueous Lubrication, Structure and Rheological Properties of Whey Protein Microgel Particles.

    Science.gov (United States)

    Sarkar, Anwesha; Kanti, Farah; Gulotta, Alessandro; Murray, Brent S; Zhang, Shuying

    2017-12-26

    Aqueous lubrication has emerged as an active research area in recent years due to its prevalence in nature in biotribological contacts and its enormous technological soft-matter applications. In this study, we designed aqueous dispersions of biocompatible whey-protein microgel particles (WPM) (10-80 vol %) cross-linked via disulfide bonding and focused on understanding their rheological, structural and biotribological properties (smooth polydimethylsiloxane (PDMS) contacts, R a ball bearings", the latter supported by negligible change in size and microstructure of the WPM particles after tribology. An ultralow boundary friction coefficient, μ ≤ 0.03 was achieved using WPM between O 2 plasma-treated hydrophilic PDMS contacts coated with bovine submaxillary mucin (water contact angle 47°), and electron micrographs revealed that the WPM particles spread effectively as a layer of particles even at low ϕ∼ 10%, forming a lubricating load-bearing film that prevented the two surfaces from true adhesive contact. However, above an optimum volume fraction, μ increased in HL+BSM surfaces due to the interpenetration of particles that possibly impeded effective rolling, explaining the slight increase in friction. These effects are reflected in the highly shear thinning nature of the WPM dispersions themselves plus the tendency for the apparent viscosity to fall as dispersions are forced to very high volume fractions. The present work demonstrates a novel approach for providing ultralow friction in soft polymeric surfaces using proteinaceous microgel particles that satisfy both load bearing and kinematic requirements. These findings hold great potential for designing biocompatible particles for aqueous lubrication in numerous soft matter applications.

  15. The effect of solid content on silylated-γ-AI2O3/PVDF-HFP-coated PE separators for lithium secondary battery

    International Nuclear Information System (INIS)

    Im, Jong Su; Sohn, Joon Yong; Shin, Jun Hwa; Nho, Young Chang; Kim, Jeong Soo

    2009-01-01

    Several PVDF-HFP/silylated γ-AI 2 O 3 -coated PE (polyethylene) separators with various solidities (various compositions of PVDF-HFP/silylated γ-AI 2 O 3 ) were prepared by a dip-coating of PE separators in PVDF-HFP/silylated γ-AI 2 O 3 /acetone mixtures. FT-IR spectroscopy was used to confirm the chemical reactions between silane coupling agent and γ-AI 2 O 3 . The SEM images of the coated separators showed that various morphologies could be produced by changing the composition of total contents of binder and solid contents. The effects of composition in inorganic material (silane coupling agent-treated γ-AI 2 O 3 ) and binder (PVDF-HFP) on the physio-chemical properties of the prepared separators such as liquid electrolyte uptake, and ion conductivity were investigated and reported in this paper

  16. 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)

  17. 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)

  18. The Effects of Particle Size on the Surface Properties of an HVOF Coating of WC-Co

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Tong Yul; Yoon, Jae Hong; Yoon, Sang Hwan; Joo, Yun Kon [Changwon National University, Changwon (Korea, Republic of); Choi, Won Ho; Son, Young Bok [Xinix Metallizing Co., Ltd, Gyungnam (Korea, Republic of)

    2017-04-15

    The effects of particle size on the surface properties of HVOF spray coating were studied to improve of the durability of metal components. Micro and nano sized WC-12Co powders were coated on the surface of Inconel718, and the effects of particle size on surface properties were studied. Surface hardness was reduced when the particle sizes of the powder were decreased, because the larger specific surface area of the smaller particles caused greater heat absorption and decomposition of the hard WC to less hard W{sub 2}C and graphite. Porosity was increased by decreasing the particle size, because the larger specific surface area of the smaller particles caused a greater decomposition of WC to W{sub 2}C and free carbon. The free carbon formed carbon oxide gases which created the porous surface. The friction coefficient was reduced by decreasing the particle size because the larger specific surface area of the smaller particles produced more free carbon free Co and Co oxide which acted as solid lubricants. The friction coefficient increased when the surface temperature was increased from 25 to 500 ℃, due to local cold welding. To improve the durability of metal mechanical components, WC-Co coating with the proper particle size is recommended.

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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.)

  5. 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

  6. 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.

  7. 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.

  8. Solid-state dewetting of continuous thin platinum coatings

    Energy Technology Data Exchange (ETDEWEB)

    Hanief, N. [University of Cape Town, Private Bag X3, Rondebosch 7701 (South Africa); Topić, M.; Pineda-Vargas, C. [iThemba LABS, National Research Foundation, P.O. Box 722, Somerset West (South Africa)

    2015-11-15

    Thermal stability of coatings is of crucial importance for reliability of electronic devices operating at high temperature. Thus, we investigated the Cr–Pt system where a thin platinum coating of 0.1 μm was deposited on chromium substrate and annealed at 1000 °C for 8 h. The scanning electron microscope (SEM) showed that a continuous and uniformly deposited Pt coating experienced the formation of “islands” after annealing. The grain-boundary grooving, dewetting and agglomeration were the main mechanisms of degradation of thermally annealed coatings. Results by μ-PIXE (particle-induced X-ray emission) and transmission electron microscope (TEM) showed the presence of Cr{sub 3}Pt phase in “islands” and the coating thickness was approximately 0.5 μm. The surrounding regions were left uncovered due to coating agglomeration at the expense of initially deposited coating.

  9. Poly(Dimethylsiloxane)-Poly(Vinyl Alcohol) Coated Solid Phase Micro extraction Fiber for Chloropyrifos Analysis

    International Nuclear Information System (INIS)

    Wan Aini Wan Ibrahim; Nor Fairul Zukry Ahmad Rasdy; Norfazilah Muhamad

    2016-01-01

    Traditional liquid - liquid extraction of pesticides consumes large volumes of organic solvent which are hazardous to the operator and is not environment friendly. Solid phase micro extraction (SPME) is a solvent less extraction method which is safer to the operator and is environmental friendly. A sol-gel hybrid fibre coating material, poly(dimethylsiloxane)-poly(vinyl alcohol) (PDMS-PVA) was synthesized and used in head space solid phase micro extraction (HS-SPME) of chloropyrifos. The thickness of the synthesised PDMS-PVA fiber coating was 13.5 μm and it is thermally stable up to 400 degree Celsius. The PDMS-PVA sol-gel hybrid fiber was also stable to two organic solvents tested; acetonitrile and dichloromethane (1 hour dipping) and showed no significant changes in extraction performance for chloropyrifos. Extracted chloropyrifos was analysed using gas chromatography electron capture detector (GC-ECD). Optimum SPME parameters affecting the PDMS-PVA HS-SPME performance namely extraction time (15 min), extraction temperature (50 degree Celsius), desorption time (5 min), desorption temperature (260 degree Celsius) and stirring rate (120 rpm) were used for extraction. It was found that HSSPME using PDMS-PVA sol-gel fiber gave significantly better extraction performance of chloropyrifos compared to commercial 100 μm PDMS fiber. The PDMS-PVA fiber showed excellent operational performances such as temperature stability (up to 380 degree Celsius), coating lifetime (up to 170 times use) and organic solvent stability. The PDMS-PVA-HS-SPME method showed excellent recovery for chloropyrifos from tomatoes (98.0 %, 5.9 % RSD) at 0.01 μg/ g spiked level (5 times lower than maximum residue limit set by European Union). (author)

  10. 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.

  11. 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.

  12. 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.)

  13. Investigation of the potential for direct compaction of a fine ibuprofen powder dry-coated with magnesium stearate.

    Science.gov (United States)

    Qu, Li; Zhou, Qi Tony; Gengenbach, Thomas; Denman, John A; Stewart, Peter J; Hapgood, Karen P; Gamlen, Michael; Morton, David A V

    2015-05-01

    Intensive dry powder coating (mechanofusion) with tablet lubricants has previously been shown to give substantial powder flow improvement. This study explores whether the mechanofusion of magnesium stearate (MgSt), on a fine drug powder can substantially improve flow, without preventing the powder from being directly compacted into tablets. A fine ibuprofen powder, which is both cohesive and possesses a low-melting point, was dry coated via mechanofusion with between 0.1% and 5% (w/w) MgSt. Traditional low-shear blending was also employed as a comparison. No significant difference in particle size or shape was measured following mechanofusion. For the low-shear blended powders, only marginal improvement in flowability was obtained. However, after mechanofusion, substantial improvements in the flow properties were demonstrated. Both XPS and ToF-SIMS demonstrated high degrees of a nano-scale coating coverage of MgSt on the particle surfaces from optimized mechanofusion. The study showed that robust tablets were produced from the selected mechanofused powders, at high-dose concentration and tablet tensile strength was further optimized via addition of a Polyvinylpyrrolidone (PVP) binder (10% w/w). The tablets with the mechanofused powder (with or without PVP) also exhibited significantly lower ejection stress than those made of the raw powder, demonstrating good lubrication. Surprisingly, the release rate of drug from the tablets made with the mechanofused powder was not retarded. This is the first study to demonstrate such a single-step dry coating of model drug with MgSt, with promising flow improvement, flow-aid and lubrication effects, tabletability and also non-inhibited dissolution rate.

  14. Friction, Wear, and Evaporation Rates of Various Materials in Vacuum to 10(exp -7) mm Hg

    Science.gov (United States)

    Buckley, Donald H.; Swikert, Max; Johnson, Robert L.

    1961-01-01

    The requirements for bearings and seals to operate in the environment of space dictate a new area for lubrication research. The low ambient pressures encountered in space can be expected to influence the behavior of oil, grease, and solid-film lubricants. The property of these materials most significantly affected by low ambient pressures is the evaporation rate. Various investigators have therefore measured the evaporation rates of oils and greases in vacuum as one method of establishing their relative merit for space applications (1-3). The results of this work have given some indication as to the oils and greases with the greatest stability at reduced ambient pressures. Only limited experimental work, however, has been reported in the literature for inorganic solids and soft metals which have potential use as solid lubricant films or coatings for hard alloy substrates [e.g. Reference ( 4 )]. In general, the evaporation rates of these materials would be lower than those of oils and greases. These films might therefore be very attractive as lubricants for high vacuum service.

  15. Friction and wear of stainless steel, titanium and aluminium with various surface treatments, ion implantation and overlay hard coatings

    International Nuclear Information System (INIS)

    Bunshah, R.F.

    1979-01-01

    This paper deals with the evaluation of the wear properties of 304 stainless steel, commercial grade titanium and commercial grade aluminium without and with different surface treatments, i.e., ion implantation of boron and nitrogen, and overlay coating of superhard materials, titanium carbide and nitride by the Biased Activated Reactive Evaporation (BARE) process. Wear properties were evaluated in adhesive, erosive and abrasive modes of wear. In the case of adhesive wear, ion implantation resulted in an improved wear behaviour in lubricated conditions but had no beneficial effect in dry wear conditions. Overlay coatings on the other hand resulted in improved wear behaviour for both the dry and lubricating conditions. In the case of erosive wear with SiC particles at high velocities, overlay coatings showed higher erosion rates (typical of brittle materials in normal impingement) whereas ion implanted materials behaved similarly as untreated materials; i.e., a lower wear rate than the specimens with overlay coatings. In the case of abrasive wear, it was again observed that the wear rates of overlay coatings is far lower than the wear rates of untreated or ion implanted materials. (author)

  16. Tribological study of lubricious DLC biocompatible coatings.

    Science.gov (United States)

    Brizuela, M; Garcia-Luis, A; Viviente, J L; Braceras, I; Oñate, J I

    2002-12-01

    DLC (diamond-like carbon) coatings have remarkable tribological properties due mainly to their good frictional behavior. These coatings can be applied in many industrial and biomedical applications, where sliding can generate wear and frictional forces on the components, such as orthopaedic metal implants. This work reports on the development and tribological characterization of functionally gradient titanium alloyed DLC coatings. A PVD-magnetron sputtering technique has been used as the deposition method. The aim of this work was to study the tribological performance of the DLC coating when metal to metal contact (cobalt chromium or titanium alloys) takes place under dry and lubricated test conditions. Prior work by the authors demonstrates that the DLC coating reduced considerably the wear of the ultra-high-molecular-weight polyethylene (UHMWPE). The DLC coating during mechanical testing exhibited a high elastic recovery (65%) compared to the values obtained from Co-Cr-Mo (15%) and Ti-6Al-4V (23%). The coating exhibited an excellent tribo-performance against the Ti-6Al-4V and Co-Cr-Mo alloys, especially under dry conditions presenting a friction value of 0.12 and almost negligible wear. This coating has passed biocompatibility tests for implant devices on tissue/bone contact according to international standards (ISO 10993).

  17. SOLID RADIOACTIVE WASTE STORAGE TECHNOLOGIES: PERFORMANCE OF A POLYMER SEALANT COATING IN AN ARCTIC MARINE ENVIRONMENT

    International Nuclear Information System (INIS)

    COWGILL, M.G.; MOSKOWITZ, P.D.; CHERNAENKO, L.M.; NAZARIAN, A.; GRIFFITH, A.; DIASHEV, A.; ENGOY, T.

    2000-01-01

    This first project, under the auspices of the Arctic Military Environmental Cooperation (AMEC) forum, Project 1.4-1 Solid Radioactive Waste Storage Technologies, successfully demonstrated the feasibility of using a polymer-based coating to seal concrete and steel surfaces from permanent radioactive contamination in an Arctic marine environment. A mobile, self-sufficient spraying device, was developed to specifications provided by the Russian Ministry of Defence Northern Navy and was deployed at the RTP Atomflot site, Murmansk, Russia. Demonstration coatings of Polibrid 705 were applied to concrete surfaces exposed to conditions ranging from indoor pedestrian usage to heavy vehicle passage and container handling in a loading bay. A large steel container was also coated with the polymer, filled with solid radwaste, sealed, and left out of doors and exposed to the full 12 month Arctic weather cycle. The field tests were accompanied by a series of laboratory qualification tests carried out at the research laboratory of ICC Nuclide in St. Petersburg. During the 12-month field tests, the sealant coating showed little sign of degradation except for a few chips and gouge marks on the loading bay surface that were readily repaired. Contamination resulting from radwaste handling was easily removed and the surface was not degraded by contact with the decontamination agents. In the laboratory testing, Polibrid 705 met all the Russian qualification requirements with the exception of flammability. In this last instance, it was decided to restrict application of the coating to land-based facilities. The Russian technical experts from the Ministry of Defence quickly familiarized themselves with the equipment and were able to identify several areas of potential improvement as deployment of the equipment progressed. The prime among these was the desirability of extending the range of the equipment through enlarged gasoline tanks (to permit extended operational times) and longer

  18. SOLID RADIOACTIVE WASTE STORAGE TECHNOLOGIES: PERFORMANCE OF A POLYMER SEALANT COATING IN AN ARCTIC MARINE ENVIRONMENT

    Energy Technology Data Exchange (ETDEWEB)

    COWGILL,M.G.; MOSKOWITZ,P.D.; CHERNAENKO,L.M.; NAZARIAN,A.; GRIFFITH,A.; DIASHEV,A.; ENGOY,T.

    2000-06-14

    This first project, under the auspices of the Arctic Military Environmental Cooperation (AMEC) forum, Project 1.4-1 Solid Radioactive Waste Storage Technologies, successfully demonstrated the feasibility of using a polymer-based coating to seal concrete and steel surfaces from permanent radioactive contamination in an Arctic marine environment. A mobile, self-sufficient spraying device, was developed to specifications provided by the Russian Ministry of Defence Northern Navy and was deployed at the RTP Atomflot site, Murmansk, Russia. Demonstration coatings of Polibrid 705 were applied to concrete surfaces exposed to conditions ranging from indoor pedestrian usage to heavy vehicle passage and container handling in a loading bay. A large steel container was also coated with the polymer, filled with solid radwaste, sealed, and left out of doors and exposed to the full 12 month Arctic weather cycle. The field tests were accompanied by a series of laboratory qualification tests carried out at the research laboratory of ICC Nuclide in St. Petersburg. During the 12-month field tests, the sealant coating showed little sign of degradation except for a few chips and gouge marks on the loading bay surface that were readily repaired. Contamination resulting from radwaste handling was easily removed and the surface was not degraded by contact with the decontamination agents. In the laboratory testing, Polibrid 705 met all the Russian qualification requirements with the exception of flammability. In this last instance, it was decided to restrict application of the coating to land-based facilities. The Russian technical experts from the Ministry of Defence quickly familiarized themselves with the equipment and were able to identify several areas of potential improvement as deployment of the equipment progressed. The prime among these was the desirability of extending the range of the equipment through enlarged gasoline tanks (to permit extended operational times) and longer

  19. 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.

  20. Heat Transfer Enhancement During Water and Hydrocarbon Condensation on Lubricant Infused Surfaces.

    Science.gov (United States)

    Preston, Daniel J; Lu, Zhengmao; Song, Youngsup; Zhao, Yajing; Wilke, Kyle L; Antao, Dion S; Louis, Marcel; Wang, Evelyn N

    2018-01-11

    Vapor condensation is routinely used as an effective means of transferring heat or separating fluids. Dropwise condensation, where discrete droplets form on the condenser surface, offers a potential improvement in heat transfer of up to an order of magnitude compared to filmwise condensation, where a liquid film covers the surface. Low surface tension fluid condensates such as hydrocarbons pose a unique challenge since typical hydrophobic condenser coatings used to promote dropwise condensation of water often do not repel fluids with lower surface tensions. Recent work has shown that lubricant infused surfaces (LIS) can promote droplet formation of hydrocarbons. In this work, we confirm the effectiveness of LIS in promoting dropwise condensation by providing experimental measurements of heat transfer performance during hydrocarbon condensation on a LIS, which enhances heat transfer by ≈450% compared to an uncoated surface. We also explored improvement through removal of noncondensable gases and highlighted a failure mechanism whereby shedding droplets depleted the lubricant over time. Enhanced condensation heat transfer for low surface tension fluids on LIS presents the opportunity for significant energy savings in natural gas processing as well as improvements in thermal management, heating and cooling, and power generation.

  1. Bimetallic nanoparticles for surface modification and lubrication of MEMS switch contacts

    International Nuclear Information System (INIS)

    Patton, Steven T; Hu Jianjun; Slocik, Joseph M; Campbell, Angela; Naik, Rajesh R; Voevodin, Andrey A

    2008-01-01

    Reliability continues to be a critical issue in microelectromechanical systems (MEMS) switches. Failure mechanisms include high contact resistance (R), high adhesion, melting/shorting, and contact erosion. Little previous work has addressed the lubrication of MEMS switches. In this study, bimetallic nanoparticles (NPs) are synthesized using a biotemplated approach and deposited on Au MEMS switch contacts as a nanoparticle-based lubricant. Bimetallic nanoparticles are comprised of a metallic core (∼10 nm diameter gold nanoparticle) with smaller metallic nanoparticles (∼2-3 nm diameter Pd nanoparticles) populating the core surface. Adhesion and resistance (R) were measured during hot switching experiments at low (10 μA) and high (1 mA) current. The Au/Pd NP coated contacts led to reduced adhesion as compared to pure Au contacts with a compromise of slightly higher R. For switches held in the closed position at low current, R gradually decreased over tens of seconds due to increased van der Waals force and growth of the real area of contact with temporal effects being dominant over load effects. Contact behavior transitioned from 'Pd-like' to 'Au-like' during low current cycling experiments. Melting at high current resulted in rapid formation of large real contact area, low and stable R, and minimal effect of load on R. Durability at high current was excellent with no failure through 10 6 hot switching cycles. Improvement at high current is due to controlled nanoscale surface roughness that spreads current through multiple nanocontacts, which restricts the size of melting regions and causes termination of nanowire growth (prevents shorting) during contact opening. Based on these results, bimetallic NPs show excellent potential as surface modifiers/lubricants for MEMS switch contacts

  2. 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...

  3. 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.

  4. 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....

  5. Tribological behavior of zirconium coatings in high temperature helium

    International Nuclear Information System (INIS)

    Cachon, Lionel; Albaladejo, Serge; Taraud, Pascal

    2005-01-01

    In France, a comprehensive research and development program is leaded by the CEA, since 2001, for the Gas Cooled Reactor (GCR) project using helium as cooling fluid, in order to establish the feasibility of the technology of an early VHTR prototype to be started by 2015, and then to qualify the generic VHTR technology, so as to meet similar objectives for the GFR. In this frame a tribology program has been launched. The purpose of the work presented in this paper is to describe the CEA Helium tribology study: high temperature gas cooled reactors require wear protection (thermal barriers, control rod drive mechanisms, reactor internals, ...). Tests in helium atmosphere are necessary to be fully representative of tribological environments and finally to check the possible materials or coatings which can provide a reliable answer to these situations. The main characteristics and first experimental results are thus described. This paper focus on tribology tests leaded in the temperature range 800-1000degC, on ceramic (ZrO 2 -Y 2 O 3 ) with and without solid lubricant like CaF2). (author)

  6. 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.

  7. 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.

  8. 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.

  9. Coated armor system and process for making the same

    Science.gov (United States)

    Chu, Henry S.; Lillo, Thomas M.; McHugh, Kevin M.

    2010-11-23

    An armor system and method involves providing a core material and a stream of atomized coating material that comprises a liquid fraction and a solid fraction. An initial layer is deposited on the core material by positioning the core material in the stream of atomized coating material wherein the solid fraction of the stream of atomized coating material is less than the liquid fraction of the stream of atomized coating material on a weight basis. An outer layer is then deposited on the initial layer by positioning the core material in the stream of atomized coating material wherein the solid fraction of the stream of atomized coating material is greater than the liquid fraction of the stream of atomized coating material on a weight basis.

  10. 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

  11. 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:

  12. 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.

  13. 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.

  14. A Study on DLC Tool Coating for Deep Drawing and Ironing of Stainless Steel

    DEFF Research Database (Denmark)

    Üstünyagiz, Esmeray; Hafis Sulaiman, Mohd; Christiansen, Peter

    2018-01-01

    ) to replicate industrial ironing of deep drawn, stainless steel parts. Non-hazardous tribo-systems in form of a double layer Diamond-like coated tool applied under dry condition or with an environmentally friendly lubricant were investigated via emulating industrial process conditions in laboratory tests...

  15. Materials and lubrication for gear and bearing surfaces in uhv

    International Nuclear Information System (INIS)

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

    1980-06-01

    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 to (by bushings) and rotated on a fixed shaft, while the other gear was driven by a commercial rotary motion feedthrough which was 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. 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 aluminum alloys. Lubricants used singly and in concert were MoS 2 , WS 2 , Ag, hard chrome, and a MoS 2 -graphite-sodium silicate mixture. The successful gear pair was Ag-plated Al alloy and MoS 2 -graphite-sodium silicate-coated Be-Cu. Subsequent performance in the PLEED system after repeated bakeouts will also be discussed

  16. Tool Wear and Formation Mechanism of White Layer When Hard Milling H13 Steel under Different Cooling/Lubrication Conditions

    Directory of Open Access Journals (Sweden)

    Song Zhang

    2014-04-01

    Full Text Available The present work aims at revealing the formation mechanism of white layer and understanding the effects of tool wear and cooling/lubrication condition on white layer when hard milling H13 steel with coated cutting tools. Hard milling experiments were carried out, and tool wear and its effect on formation of white layer were investigated. Compared to dry cutting condition, CMQL (cryogenic minimum quantity lubrication technique can obviously reduce tool wear and prolong tool life owing to its good cooling and lubrication properties. The optical images of the subsurface materials indicate that the formation of white layer is related to tool wear; moreover, the thickness of white layer increases with the increase of tool wear. SEM (scanning electron microscope images and XRD (X-ray diffraction analysis confirm that the formation of white layer is mainly due to the mechanical effect rather than the thermal effect. It also proves that white layer is partly decreased or can be totally eliminated by optimizing process parameters under CMQL cutting condition. CMQL technique has the potential to be used for achieving prolonged tool life and enhanced surface integrity.

  17. 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)

  18. 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

  19. Characterization of the Diamond-like Carbon Based Functionally Gradient Film

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Diamond-like carbon coatings have been used as solid lubricating coatings in vacuum technology for their goodphysical and chemical properties. In this paper, the hybrid technique of unbalanced magnetron sputtering and plasmaimmersion ion implantation (PIll) was adopted to fabricate diamond-like carbon-based functionally gradient film,N/TiN/Ti(N,C)/DLC, on the 304 stainless steel substrate. The film was characterized by using Raman spectroscopyand glancing X-ray diffraction (GXRD), and the topography and surface roughness of the film was observed usingAFM. The mechanical properties of the film were evaluated by nano-indentation. The results showed that the surfaceroughness of the film was approximately 0.732 nm. The hardness and elastic modulus, fracture toughness andinterfacial fracture toughness of N/TiN/Ti(N,C)/DLC functionally gradient film were about 19.84 GPa, 190.03 GPa,3.75 MPa.m1/2 and 5.68 MPa@m1/2, respectively. Compared with that of DLC monolayer and C/TiC/DLC multilayer,this DLC gradient film has better qualities as a solid lubricating coating.

  20. 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

  1. 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.

  2. Novel SU-8/Ionic Liquid Composite for Tribological Coatings and MEMS

    Directory of Open Access Journals (Sweden)

    Leili Batooli

    2015-05-01

    Full Text Available Tribology of SU-8 polymer is increasingly relevant due to bursting use of this material in a variety of applications. This study is directed towards introduction and investigation of a novel self-lubricating composite of an ionic liquid (IL in SU-8. The new material can be utilized for fabrication of lubricating polymer coating with tunable surface properties or SU8-made elements for microelectromechanical systems (MEMS with enhanced tribological performance. It is shown that addition of IL drastically alters water affinity of the composite while UV patternability remains unmodified. A lower coefficient of friction and wear has been obtained for two investigated compositions with 4 and 10 wt % ionic liquid.

  3. 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.

  4. Electrochemical deposition of Ni–TiN nanocomposite coatings and ...

    Indian Academy of Sciences (India)

    ... as oxides (Al2O3, TiO2, SiO2) or carbide particles (SiC, WC), diamond, solid lubricant (PTFE, graphite or MoS2), or even liquid-containing microcapsules ..... which is caused to change the corrosion mechanism from localized corrosion and ...

  5. 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.

  6. 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.)

  7. Friction and wear behavior of laser cladding Ni/hBN self-lubricating composite coating

    International Nuclear Information System (INIS)

    Zhang Shitang; Zhou Jiansong; Guo Baogang; Zhou Huidi; Pu Yuping; Chen Jianmin

    2008-01-01

    Ni/hBN coating was successfully prepared on 1Cr18Ni9Ti stainless steel substrate by means of laser cladding. The microhardness profile of the composite coating along the depth direction was measured, while its cross-sectional microstructures and phase compositions were analyzed by means of scanning electron microscopy and X-ray diffraction. Moreover, the friction and wear behavior of the composite coatings sliding against Si 3 N 4 from ambient to 800 deg. C was evaluated using a ball-on-disc friction and wear tester, and the worn surface morphologies of the composite coatings and counterpart ceramic balls were observed using a scanning electron microscope. At the same time, the worn surfaces of the ceramic balls were also analyzed using a 3D non-contact surface mapping profiler as well. It was found that the laser cladding Ni/hBN coating on the stainless steel substrate had high microhardness and good friction-reducing and antiwear abilities at elevated temperatures up to 800 deg. C. The composite coating registered slightly increased friction coefficient and wear rate as the temperature rose from ambient to 100 deg. C; then the friction coefficient and wear rate decreased with increasing temperature up to 800 deg. C (with the slight increase in the wear rate at 700 deg. C and 800 deg. C to be an exception). The laser cladding Ni/hBN coating was dominated by mixed adhesion and abrasive wear as it slid against the ceramic ball below 300 deg. C. With further increase in the test temperature up to 400 deg. C and above, it was characterized by mild adhesion wear and plastic deformation. Since the laser cladding Ni/hBN coating registered an increased wear rate at temperatures of 600 deg. C and above, it was not suggested to be used for wear prevention and protection of the stainless steel at elevated temperature above 800 deg. C

  8. Friction and wear behavior of laser cladding Ni/hBN self-lubricating composite coating

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Shitang [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Graduate School, Chinese Academy of Sciences, Beijing 100039 (China); Zhou Jiansong [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Guo Baogang [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Graduate School, Chinese Academy of Sciences, Beijing 100039 (China); Zhou Huidi [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Pu Yuping [Central Iron and Steel Research Institute, Beijing 100081 (China); Chen Jianmin [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)], E-mail: chenjm@lzb.ac.cn

    2008-09-15

    Ni/hBN coating was successfully prepared on 1Cr18Ni9Ti stainless steel substrate by means of laser cladding. The microhardness profile of the composite coating along the depth direction was measured, while its cross-sectional microstructures and phase compositions were analyzed by means of scanning electron microscopy and X-ray diffraction. Moreover, the friction and wear behavior of the composite coatings sliding against Si{sub 3}N{sub 4} from ambient to 800 deg. C was evaluated using a ball-on-disc friction and wear tester, and the worn surface morphologies of the composite coatings and counterpart ceramic balls were observed using a scanning electron microscope. At the same time, the worn surfaces of the ceramic balls were also analyzed using a 3D non-contact surface mapping profiler as well. It was found that the laser cladding Ni/hBN coating on the stainless steel substrate had high microhardness and good friction-reducing and antiwear abilities at elevated temperatures up to 800 deg. C. The composite coating registered slightly increased friction coefficient and wear rate as the temperature rose from ambient to 100 deg. C; then the friction coefficient and wear rate decreased with increasing temperature up to 800 deg. C (with the slight increase in the wear rate at 700 deg. C and 800 deg. C to be an exception). The laser cladding Ni/hBN coating was dominated by mixed adhesion and abrasive wear as it slid against the ceramic ball below 300 deg. C. With further increase in the test temperature up to 400 deg. C and above, it was characterized by mild adhesion wear and plastic deformation. Since the laser cladding Ni/hBN coating registered an increased wear rate at temperatures of 600 deg. C and above, it was not suggested to be used for wear prevention and protection of the stainless steel at elevated temperature above 800 deg. C.

  9. Bimetallic nanoparticles for surface modification and lubrication of MEMS switch contacts

    Energy Technology Data Exchange (ETDEWEB)

    Patton, Steven T; Hu Jianjun [University of Dayton Research Institute, Dayton, OH 45469-0168 (United States); Slocik, Joseph M; Campbell, Angela; Naik, Rajesh R; Voevodin, Andrey A [Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, OH 45433-7750 (United States)], E-mail: steve.patton@wpafb.af.mil, E-mail: rajesh.naik@wpafb.af.mil

    2008-10-08

    Reliability continues to be a critical issue in microelectromechanical systems (MEMS) switches. Failure mechanisms include high contact resistance (R), high adhesion, melting/shorting, and contact erosion. Little previous work has addressed the lubrication of MEMS switches. In this study, bimetallic nanoparticles (NPs) are synthesized using a biotemplated approach and deposited on Au MEMS switch contacts as a nanoparticle-based lubricant. Bimetallic nanoparticles are comprised of a metallic core ({approx}10 nm diameter gold nanoparticle) with smaller metallic nanoparticles ({approx}2-3 nm diameter Pd nanoparticles) populating the core surface. Adhesion and resistance (R) were measured during hot switching experiments at low (10 {mu}A) and high (1 mA) current. The Au/Pd NP coated contacts led to reduced adhesion as compared to pure Au contacts with a compromise of slightly higher R. For switches held in the closed position at low current, R gradually decreased over tens of seconds due to increased van der Waals force and growth of the real area of contact with temporal effects being dominant over load effects. Contact behavior transitioned from 'Pd-like' to 'Au-like' during low current cycling experiments. Melting at high current resulted in rapid formation of large real contact area, low and stable R, and minimal effect of load on R. Durability at high current was excellent with no failure through 10{sup 6} hot switching cycles. Improvement at high current is due to controlled nanoscale surface roughness that spreads current through multiple nanocontacts, which restricts the size of melting regions and causes termination of nanowire growth (prevents shorting) during contact opening. Based on these results, bimetallic NPs show excellent potential as surface modifiers/lubricants for MEMS switch contacts.

  10. 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.

  11. 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.

  12. Standard test method for conducting friction tests of piston ring and cylinder liner materials under lubricated conditions

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    1.1 This test method covers procedures for conducting laboratory bench-scale friction tests of materials, coatings, and surface treatments intended for use in piston rings and cylinder liners in diesel or spark-ignition engines. The goal of this procedure is to provide a means for preliminary, cost-effective screening or evaluation of candidate ring and liner materials. A reciprocating sliding arrangement is used to simulate the contact that occurs between a piston ring and its mating liner near the top-dead-center position in the cylinder where liquid lubrication is least effective, and most wear is known to occur. Special attention is paid to specimen alignment, running-in, and lubricant condition. 1.2 This test method does not purport to simulate all aspects of a fired engine’s operating environment, but is intended to serve as a means for preliminary screening for assessing the frictional characteristics of candidate piston ring and liner material combinations in the presence of fluids that behave as u...

  13. 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.

  14. 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.

  15. Structure and tribological properties of MoCN-Ag coatings in the temperature range of 25–700 °C

    Energy Technology Data Exchange (ETDEWEB)

    Shtansky, D.V., E-mail: shtansky@shs.misis.ru [National University of Science and Technology “MISIS”, Leninsky Prospect 4, Moscow (Russian Federation); Bondarev, A.V.; Kiryukhantsev-Korneev, Ph.V. [National University of Science and Technology “MISIS”, Leninsky Prospect 4, Moscow (Russian Federation); Rojas, T.C.; Godinho, V.; Fernández, A. [Instituto de Ciencia de Materiales de Sevilla CSIC-US, Avda. Américo Vespucio 49, 41092 Sevilla (Spain)

    2013-05-15

    The preparation of hard coatings with low friction coefficient over a wide temperature range is still a challenge for the tribological community. The development of new nanocomposite materials consisting of different metal-ceramic phases, each of which exhibiting self-lubricating characteristics at different temperatures, may help to solve this problem. We report on the structure and tribological properties of MoCN-Ag coatings deposited by magnetron co-sputtering of Mo and C (graphite) targets and simultaneous sputtering of an Ag target either in pure nitrogen or in a gaseous mixture of Ar + N{sub 2}. The structure and elemental composition of the coatings were studied by means of X-ray diffraction, scanning and transmission electron microscopy, X-ray photoelectron spectroscopy, energy dispersive spectroscopy, Raman spectroscopy, and glow discharge optical emission spectroscopy. The tribological properties of the coatings against an Al{sub 2}O{sub 3} ball were investigated first at discrete temperatures of 25, 500, and 700 °C, and then during continuous heating in the temperature range of 25–700 °C. The coating structure and their respective wear tracks were also examined to elucidate their phase transformations during heat treatments. The lowest friction coefficients (<0.4) were observed in the temperature ranges of 25–100 °C and 400–700 °C and can be explained by the presence of a free amorphous carbon phase, which served as a lubricant at low temperatures, and by a positive role of silver and two phases forming at elevated temperatures, molybdenum oxide and silver molybdate, which provided lubrication above 400 °C. In the temperature range between 100 and 400 °C, the friction coefficient was relatively high. This problem is to be addressed in future works.

  16. Structure and tribological properties of MoCN-Ag coatings in the temperature range of 25–700 °C

    International Nuclear Information System (INIS)

    Shtansky, D.V.; Bondarev, A.V.; Kiryukhantsev-Korneev, Ph.V.; Rojas, T.C.; Godinho, V.; Fernández, A.

    2013-01-01

    The preparation of hard coatings with low friction coefficient over a wide temperature range is still a challenge for the tribological community. The development of new nanocomposite materials consisting of different metal-ceramic phases, each of which exhibiting self-lubricating characteristics at different temperatures, may help to solve this problem. We report on the structure and tribological properties of MoCN-Ag coatings deposited by magnetron co-sputtering of Mo and C (graphite) targets and simultaneous sputtering of an Ag target either in pure nitrogen or in a gaseous mixture of Ar + N 2 . The structure and elemental composition of the coatings were studied by means of X-ray diffraction, scanning and transmission electron microscopy, X-ray photoelectron spectroscopy, energy dispersive spectroscopy, Raman spectroscopy, and glow discharge optical emission spectroscopy. The tribological properties of the coatings against an Al 2 O 3 ball were investigated first at discrete temperatures of 25, 500, and 700 °C, and then during continuous heating in the temperature range of 25–700 °C. The coating structure and their respective wear tracks were also examined to elucidate their phase transformations during heat treatments. The lowest friction coefficients (<0.4) were observed in the temperature ranges of 25–100 °C and 400–700 °C and can be explained by the presence of a free amorphous carbon phase, which served as a lubricant at low temperatures, and by a positive role of silver and two phases forming at elevated temperatures, molybdenum oxide and silver molybdate, which provided lubrication above 400 °C. In the temperature range between 100 and 400 °C, the friction coefficient was relatively high. This problem is to be addressed in future works.

  17. Frictional properties of self-adaptive chromium doped tungsten–sulfur–carbon coatings at nanoscale

    Energy Technology Data Exchange (ETDEWEB)

    Zekonyte, J., E-mail: j.zekonyte@soton.ac.uk [National Centre for Advanced Tribology, Faculty of Engineering and Environment, University of Southampton, Southampton SO17 1BJ (United Kingdom); Cavaleiro, A. [SEG-CEMUC – Department of Mechanical Engineering, University of Coimbra, Rua Luís Reis Santos, P-3030 788 Coimbra (Portugal); Polcar, T. [National Centre for Advanced Tribology, Faculty of Engineering and Environment, University of Southampton, Southampton SO17 1BJ (United Kingdom); Department of Control Engineering, Faculty of Electrical Engineering, Czech Technical University in Prague, Technická 2, Prague 6 (Czech Republic)

    2014-06-01

    Transition metal dichalcogenides (TMD) are excellent dry lubricants forming thin (∼10 nm) tribolayer that simultaneously protects the coating from environmental attack and provides low friction. In this paper, we focus on nanoscale frictional properties of chromium doped tungsten–sulfur–carbon (WSC–Cr) coatings with various Cr content. Friction force microscopy was used to investigate friction force as a function of load. A non-linear contact area dependence on the normal force was observed. The calculated interfacial shear strength was relatively low in the region of 70–99 MPa. Friction coefficient decreased with increased applied load independently of chromium content in the coatings.

  18. Comparison of iron and copper doped manganese cobalt spinel oxides as protective coatings for solid oxide fuel cell interconnects

    DEFF Research Database (Denmark)

    Talic, Belma; Molin, Sebastian; Wiik, Kjell

    2017-01-01

    MnCo2O4, MnCo1.7Cu0.3O4 and MnCo1.7Fe0.3O4 are investigated as coatings for corrosion protection of metallic interconnects in solid oxide fuel cell stacks. Electrophoretic deposition is used to deposit the coatings on Crofer 22 APU alloy. All three coating materials reduce the parabolic oxidation...... rate in air at 900 °C and 800 °C. At 700 °C there is no significant difference in oxidation rate between coated samples and uncoated pre-oxidized Crofer 22 APU. The cross-scale area specific resistance (ASR) is measured in air at 800 °C using La0.85Sr0.1Mn1.1O3 (LSM) contact plates to simulate...... contain significant amounts of Cr after aging, while all three coatings effectively prevent Cr diffusion into the LSM. A complex Cr-rich reaction layer develops at the coating-alloy interface during oxidation. Cu and Fe doping reduce the extent of this reaction layer at 900 °C, while at 800 °C the effect...

  19. Preparation of sulfonated graphene/polypyrrole solid-phase microextraction coating by in situ electrochemical polymerization for analysis of trace terpenes.

    Science.gov (United States)

    Zhang, Chengjiang; Zhang, Zhuomin; Li, Gongke

    2014-06-13

    In this study, a novel sulfonated graphene/polypyrrole (SG/PPy) solid-phase microextraction (SPME) coating was prepared and fabricated on a stainless-steel wire by a one-step in situ electrochemical polymerization method. Crucial preparation conditions were optimized as polymerization time of 15min and SG doping amount of 1.5mg/mL. SG/PPy coating showed excellent thermal stability and mechanical durability with a long lifespan of more than 200 stable replicate extractions. SG/PPy coating demonstrated higher extraction selectivity and capacity to volatile terpenes than commonly-used commercial coatings. Finally, SG/PPy coating was practically applied for the analysis of volatile components from star anise and fennel samples. The majority of volatile components identified were terpenes, which suggested the ultra-high extraction selectivity of SG/PPy coating to terpenes during real analytical projects. Four typical volatile terpenes were further quantified to be 0.2-27.4μg/g from star anise samples with good recoveries of 76.4-97.8% and 0.1-1.6μg/g from fennel samples with good recoveries of 80.0-93.1%, respectively. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Flexible diamond-like carbon thin film coated on rubbers: fundamentals and applications

    NARCIS (Netherlands)

    Pei, Yutao

    2015-01-01

    Dynamic rubber seals are the major source of friction in lubrication systems and bearings, which may take up to 70% of the total friction. Our solution is to coat rubbers with flexible diamond-like carbon (DLC) thin film by which the coefficient of friction is reduced from above 1.5 to below 0.15.

  1. 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...

  2. 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

  3. Fourier emission infrared microspectrophotometer for surface analysis. I - Application to lubrication problems

    Science.gov (United States)

    Lauer, J. L.; King, V. W.

    1979-01-01

    A far-infrared interferometer was converted into an emission microspectrophotometer for surface analysis. To cover the mid-infrared as well as the far-infrared the Mylar beamsplitter was made replaceable by a germanium-coated salt plate, and the Moire fringe counting system used to locate the moveable Michelson mirror was improved to read 0.5 micron of mirror displacement. Digital electronics and a dedicated minicomputer were installed for data collection and processing. The most critical element for the recording of weak emission spectra from small areas was, however, a reflecting microscope objective and phase-locked signal detection with simultaneous referencing to a blackbody source. An application of the technique to lubrication problems is shown.

  4. Plasma-Functionalized Polytetrafluoroethylene Nanoparticles for Improved Wear in Lubricated Contact

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Vinay [Materials Science; Timmons, Richard [Chemistry and Biochemistry, University of Texas at Arlington, P.O. Box 19065, Arlington, Texas 76019, United States; Erdemir, Ali [Argonne National Lab, Argonne, Illinois 60439, United States; Aswath, Pranesh B. [Materials Science

    2017-07-20

    Plasma-functionalized polytetrafluoroethylene (PTFE) nanoparticles were employed to evaluate their utility in improving the lubrication property of a group III mineral oil with a significantly low amount of zinc dialkyl dithiophosphate (ZDDP). The particles were coated with two consecutive films; the initial coating contained silica to enhance amorphous glassy tribofilm formation, followed by a methacrylate film to protect the silica coating and enhance dispersibility in the oil. The functionalized nanoparticles were evaluated for their tribological performance using a high-frequency reciprocating rig, in a cylinder-on-flat configuration. The oil formulations containing ZDDP (350 ppm phosphorus level) and the functionalized nanoparticles resulted in dramatic reductions in the friction coefficient and overall wear compared to the samples containing nonfunctionalized PTFE nanoparticles, ZDDP (350 ppm P), and samples devoid of nanoparticles but containing ZDDP with a 700 ppm P treat rate. XPS and XANES spectroscopy were employed to characterize the tribological films formed on the test samples. The samples with functionalized particles and ZDDP clearly exhibited tribofilms with Si- and F-doped polyphosphates of Zn coupled with the presence of ZnS at the metal-tribofilm interface. On the other hand, oils without the functionalized nanoparticles have oxides of Fe and to a lesser extent short-chain phosphates of Zn. The overall results suggest that the synergism between plasma-coated PTFE nanoparticles and ZDDP contributed to the development of protective tribofilms even at reduced amount of phosphorus in the oil. This new method of employing nanoparticles to deliver novel antifriction and antiwear chemistries at the tribological interfaces stands out as a promising approach to further reduce P levels in oils without compromising friction and wear performance.

  5. 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.

  6. 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

  7. 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...

  8. 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.

  9. Octadecyltrimethoxysilane functionalized ZnO nanorods as a novel coating for solid-phase microextraction with strong hydrophobic surface.

    Science.gov (United States)

    Zeng, Jingbin; Liu, Haihong; Chen, Jinmei; Huang, Jianli; Yu, Jianfeng; Wang, Yiru; Chen, Xi

    2012-09-21

    In this paper, we have, for the first time, proposed an approach by combining self-assembled monolayers (SAMs) and nanomaterials (NMs) for the preparation of novel solid-phase microextraction (SPME) coatings. The self-assembly of octadecyltrimethoxysilane (OTMS) on the surface of ZnO nanorods (ZNRs) was selected as a model system to demonstrate the feasibility of this approach. The functionalization of OTMS on the surface of ZNRs was characterized and confirmed using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The OTMS-ZNRs coated fiber exhibited stronger hydrophobicity after functionalization, and its extraction efficiency for non-polar benzene homologues was increased by a factor of 1.5-3.6 when compared to a ZNRs fiber with almost identical thickness and façade. In contrast, the extraction efficiency of the OTMS-ZNRs coated fiber for polar aldehydes was 1.6-4.0-fold lower than that of the ZNRs coated fiber, further indicating its enhanced surface hydrophobicity. The OTMS-ZNRs coated fiber revealed a much higher capacity upon increasing the OTMS layer thickness to 5 μm, leading to a factor of 12.0-13.4 and 1.8-2.5 increase in extraction efficiency for the benzene homologues relative to a ZNRs coated fiber and a commercial PDMS fiber, respectively. The developed HS-SPME-GC method using the OTMS-ZNRs coated fiber was successfully applied to the determination of the benzene homologues in limnetic water samples with recovery ranging from 83 to 113% and relative standard deviations (RSDs) of less than 8%.

  10. Black molecular adsorber coatings for spaceflight applications

    Science.gov (United States)

    Abraham, Nithin S.; Hasegawa, Mark M.; Straka, Sharon A.

    2014-09-01

    The molecular adsorber coating is a new technology that was developed to mitigate the risk of on-orbit molecular contamination on spaceflight missions. The application of this coating would be ideal near highly sensitive, interior surfaces and instruments that are negatively impacted by outgassed molecules from materials, such as plastics, adhesives, lubricants, epoxies, and other similar compounds. This current, sprayable paint technology is comprised of inorganic white materials made from highly porous zeolite. In addition to good adhesion performance, thermal stability, and adsorptive capability, the molecular adsorber coating offers favorable thermal control characteristics. However, low reflectivity properties, which are typically offered by black thermal control coatings, are desired for some spaceflight applications. For example, black coatings are used on interior surfaces, in particular, on instrument baffles for optical stray light control. Similarly, they are also used within light paths between optical systems, such as telescopes, to absorb light. Recent efforts have been made to transform the white molecular adsorber coating into a black coating with similar adsorptive properties. This result is achieved by optimizing the current formulation with black pigments, while still maintaining its adsorption capability for outgassing control. Different binder to pigment ratios, coating thicknesses, and spray application techniques were explored to develop a black version of the molecular adsorber coating. During the development process, coating performance and adsorption characteristics were studied. The preliminary work performed on black molecular adsorber coatings thus far is very promising. Continued development and testing is necessary for its use on future contamination sensitive spaceflight missions.

  11. 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...

  12. 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."

  13. Sol-gel titania-coated needles for solid phase dynamic extraction-GC/MS analysis of desomorphine and desocodeine.

    Science.gov (United States)

    Su, Chi-Ju; Srimurugan, Sankarewaran; Chen, Chinpiao; Shu, Hun-Chi

    2011-01-01

    Novel sol-gel titania film coated needles for solid-phase dynamic extraction (SPDE)-GC/MS analysis of desomorphine and desocodeine are described. The high thermal stability of titania film permits efficient extraction and analysis of poorly volatile opiate drugs. The influences of sol-gel reaction time, coating layer, extraction and desorption time and temperature on the SPDE needle performance were investigated. The deuterium labeled internal standard was introduced either during the extraction of analyte or directly injected to GC after the extraction process. The latter method was shown to be more sensitive for the analysis of water and urine samples containing opiate drugs. The proposed conditions provided a wide linear range (from 5-5000 ppb), and satisfactory linearity, with R(2) values from 0.9958 to 0.9999, and prominent sensitivity, LOQs (1.0-5.0 ng/g). The sol-gel titania film coated needle with SPDE-GC/MS will be a promising technique for desomorphine and desocodeine analysis in urine.

  14. 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...

  15. 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...

  16. 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)

  17. Theoretical voltammetric response of electrodes coated by solid polymer electrolyte membranes.

    Science.gov (United States)

    Gómez-Marín, Ana M; Hernández-Ortíz, Juan P

    2014-09-24

    A model for the differential capacitance of metal electrodes coated by solid polymer electrolyte membranes, with acid/base groups attached to the membrane backbone, and in contact with an electrolyte solution is developed. With proper model parameters, the model is able to predict a limit response, given by Mott-Schottky or Gouy-Chapman-Stern theories depending on the dissociation degree and the density of ionizable acid/base groups. The model is also valid for other ionic membranes with proton donor/acceptor molecules as membrane counterions. Results are discussed in light of the electron transfer rate at membrane-coated electrodes for electrochemical reactions that strongly depend on the double layer structure. In this sense, the model provides a tool towards the understanding of the electro-catalytic activity on modified electrodes. It is shown that local maxima and minima in the differential capacitance as a function of the electrode potential may occur as consequence of the dissociation of acid/base molecular species, in absence of specific adsorption of immobile polymer anions on the electrode surface. Although the model extends the conceptual framework for the interpretation of cyclic voltammograms for these systems and the general theory about electrified interfaces, structural features of real systems are more complex and so, presented results only are qualitatively compared with experiments. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Ni-Flash-Coated Galvannealed Steel Sheet with Improved Properties

    Science.gov (United States)

    Pradhan, D.; Dutta, M.; Venugopalan, T.

    2016-11-01

    In the last several years, automobile industries have increasingly focused on galvannealed (GA) steel sheet due to their superior properties such as weldability, paintability and corrosion protection. To improve the properties further, different coatings on GA have been reported. In this context, an electroplating process (flash coating) of bright and adherent Ni plating was developed on GA steel sheet for covering the GA defects and enhancing the performances such as weldability, frictional behavior, corrosion resistance and phosphatability. For better illustration, a comparative study with bare GA steel sheet has also been carried out. The maximum electroplating current density of 700 A/m2 yielded higher cathode current efficiency of 95-98%. The performances showed that Ni-coated (coating time 5-7 s) GA steel sheet has better spot weldability, lower dynamic coefficient of friction (0.07 in lubrication) and three times more corrosion resistance compared to bare GA steel sheet. Plate-like crystal of phosphate coating with size of 10-25 µm was obtained on the Ni-coated GA. The main phase in the phosphate compound was identified as hopeite (63.4 wt.%) along with other phases such as spencerite (28.3 wt.%) and phosphophyllite (8.3 wt.%).

  19. 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.

  20. Smart Nanocomposite Coatings with Chameleon Surface Adaptation in Tribological Applications

    Science.gov (United States)

    Voevodin, A. A.; Zabinski, J. S.

    Smart nanocomposite tribological coatings were designed to respond to changing environmental conditions by self-adjustment of their surface properties to maintain good tribological performance in any environment. These coatings have been dubbed "chameleon" because of their ability to change their surface chemistry and structure to avoid wear. The first "chameleon" coatings were made of WC, WS2, and DLC; these coatings provided superior mechanical toughness and performance in dry/humid environmental cycling. In order to address temperature variation, the second generation of "chameleon" coatings were made of yttria stabilized zirconia (YSZ) in a gold matrix with encapsulated nano-sized reservoirs of MoS2 and DLC. High temperature lubrication with low melting point glassy ceramic phases was also explored. All coatings were produced using a combination of laser ablation and magnetron sputtering. They were thoroughly characterized by various analytical, mechanical, and tribological methods. Coating toughness was remarkably enhanced by activation of a grain boundary sliding mechanism. Friction and wear endurance measurements were performed in controlled humidity air, dry nitrogen, and vacuum environments, as well as at 500-600 °C in air. Unique friction and wear performance in environmental cycling was demonstrated.

  1. 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

  2. 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.

  3. 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.

  4. Comparison of iron and copper doped manganese cobalt spinel oxides as protective coatings for solid oxide fuel cell interconnects

    Science.gov (United States)

    Talic, Belma; Molin, Sebastian; Wiik, Kjell; Hendriksen, Peter Vang; Lein, Hilde Lea

    2017-12-01

    MnCo2O4, MnCo1.7Cu0.3O4 and MnCo1.7Fe0.3O4 are investigated as coatings for corrosion protection of metallic interconnects in solid oxide fuel cell stacks. Electrophoretic deposition is used to deposit the coatings on Crofer 22 APU alloy. All three coating materials reduce the parabolic oxidation rate in air at 900 °C and 800 °C. At 700 °C there is no significant difference in oxidation rate between coated samples and uncoated pre-oxidized Crofer 22 APU. The cross-scale area specific resistance (ASR) is measured in air at 800 °C using La0.85Sr0.1Mn1.1O3 (LSM) contact plates to simulate the interaction with the cathode in a SOFC stack. All coated samples have three times lower ASR than uncoated Crofer 22 APU after 4370 h aging. The ASR increase with time is lowest with the MnCo2O4 coating, followed by the MnCo1.7Fe0.3O4 and MnCo1.7Cu0.3O4 coatings. LSM plates contacted to uncoated Crofer 22 APU contain significant amounts of Cr after aging, while all three coatings effectively prevent Cr diffusion into the LSM. A complex Cr-rich reaction layer develops at the coating-alloy interface during oxidation. Cu and Fe doping reduce the extent of this reaction layer at 900 °C, while at 800 °C the effect of doping is insignificant.

  5. LaCrO3/CuFe2O4 Composite-Coated Crofer 22 APU Stainless Steel Interconnect of Solid Oxide Fuel Cells

    Science.gov (United States)

    Hosseini, Seyedeh Narjes; Enayati, Mohammad Hossein; Karimzadeh, Fathallah; Dayaghi, Amir Masoud

    2017-07-01

    Rapidly rising contact resistance and cathode Cr poisoning are the major problems associated with unavoidable chromia scale growth on ferritic stainless steel (FSS) interconnects of solid oxide fuel cells. This work investigates the performance of the novel screen-printed composite coatings consisting of dispersed conductive LaCrO3 particles in a CuFe2O4 spinel matrix for Crofer 22 APU FSS, with emphasis on the oxidation behavior and electrical conductivity of these coatings. The results show that the presence of protective spinel coating, accompanied by the effective role of LaCrO3 particle incorporation, prevents the Cr2O3 subscale growth as well as chromium migration into the coating surface at the end of 400 hours of oxidation at 1073 K (800 °C) in air. In addition, the composite coatings decreased the area specific resistance (ASR) from 51.7 and 13.8 mΩ cm2 for uncoated and spinel-coated samples, respectively, to a maximum of 7.7 mΩ cm2 for composite-coated samples after 400 hours of oxidation.

  6. Phase transformation and tribological properties of Ag-MoO3 contained NiCrAlY based composite coatings fabricated by laser cladding

    Science.gov (United States)

    Wang, Lingqian; Zhou, Jiansong; Xin, Benbin; Yu, Youjun; Ren, Shufang; Li, Zhen

    2017-08-01

    Ag-MoO3 contained NiCrAlY based composite coating was successfully prepared on GH4169 stainless steel substrate by high energy ball milling and laser cladding. The microstructure and phase transformation were investigated by scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS) and X-ray diffraction spectrum (XRD). The tribological behavior and mechanism from room temperature to 800 °C were investigated. Results showed that MoO3 in the composite powders transformed to Mo2C reinforcement under the high energy density of laser, and a series of opposite transformation occurred during friction process. The coating showed the lowest friction coefficient and low wear rate at 600 °C and 800 °C due to the generation of Ag2MoO4 during tribo-chemical reactions and the formation of lubrication glaze on the worn surface. Ag made effective lubrication when the temperature rose up to 200 °C. The coating displayed a relatively high friction coefficient (about 0.51) at 400 °C, because though MoO3 (oxidation products of Mo2C) and Ag2MoO4 were detected on the worn surface, they could not realize effective lubrication at this temperature. Abrasive wear, adhesive wear and plastic deformation contributed to the increased friction and wear.

  7. Crosslinked polymeric ionic liquids as solid-phase microextraction sorbent coatings for high performance liquid chromatography.

    Science.gov (United States)

    Yu, Honglian; Merib, Josias; Anderson, Jared L

    2016-03-18

    Neat crosslinked polymeric ionic liquid (PIL) sorbent coatings for solid-phase microextraction (SPME) compatible with high-performance liquid chromatography (HPLC) are reported for the first time. Six structurally different PILs were crosslinked to nitinol supports and applied for the determination of select pharmaceutical drugs, phenolics, and insecticides. Sampling conditions including sample solution pH, extraction time, desorption solvent, desorption time, and desorption solvent volume were optimized using design of experiment (DOE). The developed PIL sorbent coatings were stable when performing extractions under acidic pH and remained intact in various organic desorption solvents (i.e., methanol, acetonitrile, acetone). The PIL-based sorbent coating polymerized from the IL monomer 1-vinyl-3-(10-hydroxydecyl) imidazolium chloride [VC10OHIM][Cl] and IL crosslinker 1,12-di(3-vinylbenzylimidazolium) dodecane dichloride [(VBIM)2C12] 2[Cl] exhibited superior extraction performance compared to the other studied PILs. The extraction efficiency of pharmaceutical drugs and phenolics increased when the film thickness of the PIL-based sorbent coating was increased while many insecticides were largely unaffected. Satisfactory analytical performance was obtained with limits of detection (LODs) ranging from 0.2 to 2 μg L(-1) for the target analytes. The accuracy of the analytical method was examined by studying the relative recovery of analytes in real water samples, including tap water and lake water, with recoveries varying from 50.2% to 115.9% and from 48.8% to 116.6%, respectively. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. 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...

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. Friction and wear of TiCN coatings deposited by filtered arc

    International Nuclear Information System (INIS)

    Huang, S.W.; Ng, K.; Samandi, M.

    1998-01-01

    A series of macroparticle-free TiN, TiCN and TiC coatings were deposited on 316 austenitic stainless steel using a titanium target in a filtered arc deposition system and reactive mixtures of CH4 and N2 gases. The microhardness of the coatings were measured by using an Ultra Microhardness Indentation System (UMIS-2000). The wear and friction of the coatings were assessed under controlled test conditions in a pin-on-disc tribometer. The results show a significant increase in microhardness and wear resistance as the CH4 :N2 gas flow rate ratio is increased. At lower load (14N), all coatings exhibited low friction and wear. At higher load (25N), the higher carbon content TiCN and TiC coatings showed a much lower friction and wear compared to TiN and low carbon TiCN. The topographical examination of coatings and worn surfaces established that the self-lubricating effect of the carbonaceous particles condensed from the plasma during the deposition was primarily responsible for the low friction and wear regime. (authors)

  14. 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.

  15. 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...

  16. Friction Modifier Using Adherent Metallic Multilayered or Mixed Element Layer Conversion Coatings

    Science.gov (United States)

    Schramm, Harry F. (Inventor); Defalco, Francis G. (Inventor); Starks, Lloyd L., Sr. (Inventor)

    2013-01-01

    A process for creating conversion coatings and spin, drawing, and extrusion finishes for surfaces, wherein the conversion coatings and spin, drawing, and extrusion finishes contain potassium, phosphorus, nitrogen, and one or more non-alkaline metals and/or one or more metalloids. The process comprises forming an aqueous solution of water, phosphoric acid or sulfuric acid, ammonium hydroxide, an alkali metal hydroxide, and one or more non-alkaline metals and/or one or more metalloids. The aqueous solution forms an anti-friction multilayer conversion and/or mixed element coating or a spin, drawing, and extrusion finish on a surface when applied to the surface, either directly without the use of applied external electromotive force, or as an additive in lubricating fluids.

  17. Development of improved lacv-30 propeller blade coatings for protection against sand and rain erosion and marine environment corrosion. Final report 4 Jan 1982-4 Mar 1983

    Energy Technology Data Exchange (ETDEWEB)

    Malone, G.A.

    1983-05-10

    An investigation was conducted of candidate systems offering potential erosion and corrosion protection when applied as coatings to Aluminum 7075 alloy propeller blades used to propel air cushioned vehicles operating in severe environments. This work focused on (1) special hard anodized and (2) hard nickel electroplated coatings as candidate protective systems with sand/rain erosion testing to evaluate their merits. Attributes of the coating systems developed and studied included: For (1) Ways and means to produce and control deposit hardness for optimum erosion resistance, methods of bonding to blades for high integrity adhesion, and inclusion of sacrificial corrosion protection electroplates in the coating systems (zinc and zinc-nickel alloy). For (2) Incorporation of dry film lubricant systems on sealed hardcoats of various anodic coating thicknesses to enhance erosion performance. Study results indicated that anodized coatings did not provide suitable erosion protection to Aluminum 7075 in sand/rain environments, even with dry film lubricant supplemental films. Electroplated hard nickel coatings, Vickers hardnesses in the range of 380 to 440, appeared better for combined sand/rain erosion resistance based on comparisons with prior work. Dilute phosphoric anodizing the aluminum substrates led to excellent bonds and improved corrosion resistance when subsequently plated with ductile nickel from a low pH bath, followed by hard nickel electroplate.

  18. 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.

  19. 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.

  20. 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.

  1. LaCrO3 composite coatings for AISI 444 stainless steel solid oxide fuel cell interconnects

    Directory of Open Access Journals (Sweden)

    Wilson Acchar

    2012-12-01

    Full Text Available Doped lanthanum chromite-based ceramics are the most widely used interconnector material in solid fuel cells (SOFC since they exhibit significant electrical and thermal conductivity, substantial corrosion resistance and adequate mechanical strength at ambient and high temperatures. The disadvantage of this material is its high cost and poor ductility. The aim of this study is to determine the mechanical and oxidation behavior of a stainless steel (AISI 444 with a LaCrO3 deposition on its surface obtained through spray pyrolisis. Coated and pure AISI 444 materials were characterized by mechanical properties, oxidation behavior, X-ray diffraction and scanning electronic microscopy. Results indicated that the coated material displays better oxidation behavior in comparison to pure stainless steel, but no improvement in mechanical strength. Both materials indicate that deformation behavior depends on testing temperatures.

  2. High Rate Deposition of Thick CrN and Cr2N Coatings Using Modulated Pulse Power (MPP) Magnetron Sputtering

    Science.gov (United States)

    2010-12-01

    AISI 440C steel using a microtribometer (Center for Tribology , Inc) in an ambient air atmosphere without a lubricant (a relative humidity of 251...that the CTE for the 440 C stainless steel substrate is 10.2x10 -6 o C -1 [37],while the CTE values for the CrN and Cr2N coatings are 2.3x10 -6...increased scratch critical load (Fig. 12) as the coating thickness was increased. Since the coating is much harder than the stainless steel substrate

  3. Evaluation of Thermal Barrier and PS-200 Self-Lubricating Coatings in an Air-Cooled Rotary Engine

    Science.gov (United States)

    Moller, Paul S.

    1995-01-01

    This project provides an evaluation of the feasibility and desirability of applying a thermal barrier coating overlaid with a wear coating on the internal surfaces of the combustion area of rotary engines. Many experiments were conducted with different combinations of coatings applied to engine components of aluminum, iron and titanium, and the engines were run on a well-instrumented test stand. Significant improvements in specific fuel consumption were achieved and the wear coating, PS-200, which was invented at NASA's Lewis Research Center, held up well under severe test conditions.

  4. A new and efficient Solid Phase Microextraction approach for analysis of high fat content food samples using a matrix-compatible coating.

    Science.gov (United States)

    De Grazia, Selenia; Gionfriddo, Emanuela; Pawliszyn, Janusz

    2017-05-15

    The current work presents the optimization of a protocol enabling direct extraction of avocado samples by a new Solid Phase Microextraction matrix compatible coating. In order to further extend the coating life time, pre-desorption and post-desorption washing steps were optimized for solvent type, time, and degree of agitation employed. Using optimized conditions, lifetime profiles of the coating related to extraction of a group of analytes bearing different physical-chemical properties were obtained. Over 80 successive extractions were carried out to establish coating efficiency using PDMS/DVB 65µm commercial coating in comparison with the PDMS/DVB/PDMS. The PDMS/DVB coating was more prone to irreversible matrix attachment on its surface, with consequent reduction of its extractive performance after 80 consecutive extractions. Conversely, the PDMS/DVB/PDMS coating showed enhanced inertness towards matrix fouling due to its outer smooth PDMS layer. This work represents the first step towards the development of robust SPME methods for quantification of contaminants in avocado as well as other fatty-based matrices, with minimal sample pre-treatment prior to extraction. In addition, an evaluation of matrix components attachment on the coating surface and related artifacts created by desorption of the coating at high temperatures in the GC-injector port, has been performed by GCxGC-ToF/MS. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Magnetic solid-phase extraction based on mesoporous silica-coated magnetic nanoparticles for analysis of oral antidiabetic drugs in human plasma

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Karynne Cristina de; Andrade, Gracielle Ferreira [Centro de Desenvolvimento da Tecnologia Nuclear, CDTN/CNEN, Rua Professor Mário Werneck, s/n. Campus Universitário, Belo Horizonte, MG CEP 30.123-970 (Brazil); Vasconcelos, Ingrid; Oliveira Viana, Iara Maíra de; Fernandes, Christian [Departamento de Produtos Farmacêuticos, Faculdade de Farmácia, Universidade Federal de Minas Gerais, Belo Horizonte, MG (Brazil); Martins Barros de Sousa, Edésia, E-mail: sousaem@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear, CDTN/CNEN, Rua Professor Mário Werneck, s/n. Campus Universitário, Belo Horizonte, MG CEP 30.123-970 (Brazil)

    2014-07-01

    In the present work, magnetic nanoparticles embedded into mesoporous silica were prepared in two steps: first, magnetite was synthesized by oxidation–precipitation method, and next, the magnetic nanoparticles were coated with mesoporous silica by using nonionic block copolymer surfactants as structure-directing agents. The mesoporous SiO{sub 2}-coated Fe{sub 3}O{sub 4} samples were functionalized using octadecyltrimethoxysilane as silanizing agent. The pure and functionalized silica nanoparticles were physicochemically and morphologically characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), N{sub 2} adsorption, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The resultant magnetic silica nanoparticles were applied as sorbents for magnetic solid-phase extraction (MSPE) of oral antidiabetic drugs in human plasma. Our results revealed that the magnetite nanoparticles were completely coated by well-ordered mesoporous silica with free pores and stable pore walls, and that the structural and magnetic properties of the Fe{sub 3}O{sub 4} nanoparticles were preserved in the applied synthesis route. Indeed, the sorbent material was capable of extracting the antidiabetic drugs from human plasma, being useful for the sample preparation in biological matrices. - Highlights: • SBA-15/Fe{sub 3}O{sub 4} was synthesized and functionalized with octadecyltrimethoxysilane. • Magnetite nanoparticles were completely coated by well-ordered mesoporous silica. • The samples were used as sorbent for magnetic solid-phase extraction (MSPE). • The sorbent material was capable of extracting drugs from human plasma. • The extraction ability makes the material a candidate to be employed as MSPE.

  6. Preparation of ultra-fine powders from polysaccharide-coated solid lipid nanoparticles and nanostructured lipid carriers by innovative nano spray drying technology.

    Science.gov (United States)

    Wang, Taoran; Hu, Qiaobin; Zhou, Mingyong; Xue, Jingyi; Luo, Yangchao

    2016-09-10

    In this study, five polysaccharides were applied as natural polymeric coating materials to prepare solid lipid nanoparticles (SLN) and nanostructure lipid carriers (NLC), and then the obtained lipid colloidal particles were transformed to solid powders by the innovative nano spray drying technology. The feasibility and suitability of this new technology to generate ultra-fine lipid powder particles were evaluated and the formulation was optimized. The spray dried SLN powder exhibited the aggregated and irregular shape and dimension, but small, uniform, well-separated spherical powder particles of was obtained from NLC. The optimal formulation of NLC was prepared by a 20-30% oleic acid content with carrageenan or pectin as coating material. Therefore, nano spray drying technology has a potential application to produce uniform, spherical, and sub-microscale lipid powder particles when the formulation of lipid delivery system is appropriately designed. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Linking Tribofilm Nanomechanics to the Origin of Low Friction and Wear

    Science.gov (United States)

    2013-08-08

    coating failure during transportation [6]. There have been a number of recent efforts to design ‘ adaptable ’ MoS2-based solid lubricants to combat...friction and severe wear. The MoS2 surface immediately responds to the applied stress and adapts to promote interfacial sliding through unclear...pp. 41-&. [8] Voevodin, A. A., Fitz, T. A., Hu, J. J., and Zabinski, J. S., 2002, "Nanocomposite tribological coatings with " chameleon " surface

  8. 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

  9. 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.

  10. 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.

  11. 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...

  12. 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

  13. 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.

  14. 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.

  15. Testing of WS2 Nanoparticles Functionalized by a Humin-Like Shell as Lubricant Additives

    Directory of Open Access Journals (Sweden)

    Hagit Sade

    2018-01-01

    Full Text Available Nanoparticles of transition metal dichalcogenides (TMDC have been known to reduce friction and wear when added to oil-type liquid lubricants. Aggregation limits the ability of the nanoparticles to penetrate into the interface between the two rubbing surfaces—an important factor in friction reduction mechanisms. Doping has been successfully used to reduce agglomeration, but it must be done in the production process of the nanoparticles. The use of surface-functionalized nanoparticles is less common than doping. Nonetheless, it has the potential to reduce agglomeration and thereby improve the reduction of friction and wear. In this study, we present the results of preliminary tribological ball-on-flat tests performed with WS2 nanoparticles functionalized by a humin-like conformal shell, as additives to polyalphaolefin-4 (PAO-4 oil. We tested WS2 inorganic nanotubes (INTs and two grades of inorganic fullerene-like nanoparticles (IFs. The shell/coating was found to improve friction reduction for IFs but not for INTs through better dispersion in the oil. The thicker the coating on the IFs, the less agglomerated they were. Coated industrial-grade IFs were found, by far, to be the best additive for friction reduction. We suggest the combination between reduced agglomeration and poor crystallinity as the reason for this result.

  16. Tribological Evaluation of Candidate Gear Materials Operating Under Light Loads in Highly Humid Conditions

    Science.gov (United States)

    Dellacorte, Christopher; Thomas, Fransua; Leak, Olivia Ann

    2015-01-01

    A series of pin-on-disk sliding wear tests were undertaken to identify candidate materials for a pair of lightly loaded timing gears operating under highly humid conditions. The target application involves water purification and thus precludes the use of oil, grease and potentially toxic solid lubricants. The baseline sliding pair is austenitic stainless steel operating against a carbon filled polyimide. The test load and sliding speed (4.9 N, 2.7 m/s) were chosen to represent average contact conditions of the meshing gear teeth. In addition to the baseline materials, the hard superelastic NiTiNOL 60 (60NiTi) was slid against itself, against the baseline polyimide, and against 60NiTi onto which a commercially deposited dry film lubricant (DFL) was applied. The alternate materials were evaluated as potential replacements to achieve a longer wear life and improved dimensional stability for the timing gear application. An attempt was also made to provide solid lubrication to self-mated 60NiTi by rubbing the polyimide against the disk wear track outside the primary 60NiTi-60NiTi contact, a method named stick or transfer-film lubrication. The selected test conditions gave repeatable friction and wear data and smooth sliding surfaces for the baseline materials similar to those in the target application. Friction and wear for self-mated stainless steel were high and erratic. Self-mated 60NiTi gave acceptably low friction (approx. 0.2) and modest wear but the sliding surfaces were rough and potentially unsuitable for the gear application. Tests in which 60NiTi pins were slid against DFL coated 60NiTi and DFL coated stainless steel gave low friction and long wear life. The use of stick lubrication via the secondary polyimide pin provided effective transfer film lubrication to self-mated 60NiTi tribological specimens. Using this approach, friction levels were equal or lower than the baseline polyimide-stainless combination and wear was higher but within data scatter observed

  17. Improvement in tribological properties of atmospheric plasma-sprayed WC-Co coating followed by Cu electrochemical impregnation

    International Nuclear Information System (INIS)

    Yuan Jianhui; Zhu Yingchun; Zheng Xuebing; Ruan Qichao; Ji Heng

    2009-01-01

    The WC-Co coating obtained by atmospheric plasma spraying (APS) was modified by Cu electrochemical impregnation. The copper has infiltrated into and filled up the pores in WC-Co coating. The tribological properties of the coating against the stainless steel ball as sliding pairs were investigated with a ball-on-disc (BOD) configuration in air at room temperature. The as-prepared samples were characterized by means of optical microscope, scanning electron microscope and X-ray diffraction. It was found that the frictional behavior of the WC-Co coating followed by Cu electrochemical impregnation was superior to that of WC-Co coating. The wear mechanism of the WC-Co coating followed by Cu electrochemical impregnation was microcutting, whilst that of a WC-Co coating was the fatigue wear. The improvement in tribological properties of the WC-Co coating followed by Cu electrochemical impregnation was attributed to the formation of self-lubricating Cu film on the wear surface which induces the transformation of wear mechanism.

  18. Effects of tablet formulation and subsequent film coating on the supersaturated dissolution behavior of amorphous solid dispersions.

    Science.gov (United States)

    Sakai, Toshiro; Hirai, Daiki; Kimura, Shin-Ichiro; Iwao, Yasunori; Itai, Shigeru

    2018-04-05

    The effects of tablet preparation and subsequent film coating with amorphous solid dispersion (ASD) particles that were composed of a drug with poor water solubility and hydrophilic polymers were investigated. ASD particles were prepared with a drug and vinylpyrrolidone-vinyl acetate copolymer (PVPVA) or polyvinylpyrrolidone (PVP) at a weight ratio of 1:1 or 1:2 using a melt extrusion technique. Tablets were prepared by conventional direct compression followed by pan coating. A mathematical model based on the Noyes-Whitney equation assuming that stable crystals precipitated at the changeable surface area of the solid-liquid interface used to estimate drug dissolution kinetics in a non-sink dissolution condition. All the ASD particles showed a maximum dissolution concentration approximately ten times higher than that of the crystalline drug. The ASD particles with PVPVA showed higher precipitation rate with lower polymer ratio, while PVP did not precipitate within 960 min regardless of the polymer ratio, suggesting the ASD particles of 1:1 drug:PVPVA (ASD-1) were the most unstable among the ASD particles considered. The dissolution of a core tablet with ASD-1 showed less supersaturation and a much higher precipitation rate than those of ASD-1 particles. However, a film-coated tablet or core tablet with a trace amount of hydroxypropylmethylcellulose (HPMC) showed a similar dissolution profile to that of the ASD-1 particles, indicating HPMC had a remarkable precipitation inhibition effect. Overall, these results suggest that tablet preparation with ASD may adversely affect the maintenance of supersaturation; however, this effect can be mitigated by adding an appropriate precipitation inhibitor to the formulation. Copyright © 2018 Elsevier B.V. All rights reserved.

  19. 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.

  20. 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.