出版者・発行元：Elsevier BV  

Abstract To determine the friction characteristic of ZnDTP-derived tribofilms, we made microscopic measurements of friction across the tribofilm under dry conditions to eliminate possible hydrodynamic action of the fluid, using a laboratory-made micro-tribometer. The friction traces showed large fluctuation during the measurement across the tribofilm due to the inhomogeneous formation of the tribofilm. We assigned measuring points of the friction coefficient using a micro-tribometer across the tribofilm point-by-point to the surface images obtained with a confocal laser microscope, SEM images, and EPMA chemical images. Based on our results, we propose a data processing method to correlate the local friction to the morphology or the local chemistry of the tribofilm. The effect of the alkyl chain of ZnDTPs is also discussed.

DOI： 10.1016/j.triboint.2016.12.027

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出版者・発行元：Informa UK Limited  

ABSTRACTZinc dialkyldithiophosphate (ZnDTP) is well known to show supreme antiwear performance by forming a thick polyphosphate-based tribofilm on the friction surface. However, it has also been demonstrated that a coexisting dispersant can interfere with the performance of ZnDTP. Because many lubricating oils contain a variety of additives in addition to ZnDTP, the effect of functional groups in the coexisting polar compounds on the tribofilm formation of ZnDTP should be clarified. In this study, several kinds of functionalized polyalkylmethacrylates (PMAs), a dispersant, and friction modifiers were used with ZnDTP, and their effects on the tribofilm formation and the friction characteristic of ZnDTP were discussed. The formulation of polar compounds with different types of functional groups significantly changed the state of ZnDTP compounds in the bulk solutions. Amino groups tended to generate coordination complex compounds and reduced the neutral ZnDTP content in the sample solutions. PMA-OH and glyce...

DOI： 10.1080/10402004.2017.1303559

DOI： 10.2474/trol.19.228_references_DOI_OqTjxqchjDnodmLp4uPXoE3tzIb

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出版者・発行元：Elsevier BV  

Abstract Although zinc dialkyldithiophosphate (ZnDTP) shows supreme antiwear performance by forming a thick polyphosphate-based tribofilm on the friction surface, it has been pointed out that the use of ZnDTP is accompanied by interference from the coexisting dispersant. For the maintenance of the good antiwear performance of ZnDTP when it is used with coexisting polar compounds, the effects of polar compounds on the tribofilm formation of ZnDTP should be clarified. Since the recent demand for minimizing energy consumption recommends applying lower-viscosity oil to reduce the viscous drag, the use of a good viscosity modifier (VM) that improves the temperature–viscosity characteristic of the oil is required. Here we tested several types of functionalized polymethacrylate (PMA)-VMs used with ZnDTP, and we discuss their effect on the tribofilm formation of ZnDTP. We observed that the PMA-series VMs with different functional groups influenced the tribofilm formation of ZnDTP. The amino-group-containing PMA in particular significantly reduced the formation of tribofilm.

DOI： 10.1016/j.triboint.2015.12.018

DOI： 10.2474/trol.19.228_references_DOI_AqNXGbMQ7hrT0LDkaNF8QrftBN0

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出版者・発行元：Elsevier BV  

Abstract Ionic liquids (ILs) have potential as high-temperature liquid lubricants based on their extremely low vapor pressure and chemical stability. There are many ILs that contain a fluorine atom in their anion moiety. However, since fluorine-containing liquid lubricants such as perfluoropolyether (PFPE) sometimes show very large wear of steel due to an excessive chemical reaction between their fluorine atom and the iron, similar excessive corrosive wear of steel is anticipated when fluorine-containing ILs are used at high temperature. Eight types of ILs with the same bis(trifluoromethanesulfonyl)amide (TFSA)-anion moiety were used as sample oils. Tribotests were carried out with a ball-on-disk-type reciprocating motion tribometer by changing the testing oil temperature from room temperature (RT) to 250 °C. X-ray photoelectron spectroscopy (XPS) analyses were carried out to determine the extent of chemical reaction. All eight of the sample ILs tested showed increase in friction and wear with the rise in temperature, and decreasing friction and wear after that. A very marked increase in wear was observed at 250 °C for all of the sample ILs, due to the deterioration of the ILs. We also found that the wear increase with increasing temperature was derived not from the excessive corrosive wear but from the reduction in the load–bearing capability of fluids due to the decrease in viscosity. In this region, the formation of metal fluoride and sulfide increased very slightly with the temperature. In the temperature range in which the friction and wear were decreased with temperature, the formation of metal fluoride and sulfide increased. A high degree of fluoride formation was detected by XPS with the PFPE lubricant, with which the level of wear was very much larger than that with the TFSA-based ILs. It can be concluded that there is no need to worry about the accelerated corrosive wear of the TFSA-based ILs up to 200 °C.

DOI： 10.1016/j.triboint.2015.01.008

DOI： 10.3390/lubricants10100275_references_DOI_86ikiMiODiz0TM8CshDxZZihKKB

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Japanese Society of Tribologists  

Friction characteristics of a finger pad sliding on a Si surface coated with organic molecular films, such as octadecyltrichrolosilane (OTS)-SAM and perfluoropolyethers (PFPE), having different film thicknesses were investigated to reveal the effect of film formation state on finger friction. The contact area of the finger pad was also measured using a black ink stamp to elucidate the interfacial phenomena between the finger pad and the surface. The results show that the friction coefficient of the finger decreased with increasing film thickness. This suggests that the friction coefficient was probably affected by surface conditions such as film formation state, even though the difference in film thickness was only a few nanometers. Assuming that the contact area remained unchanged while the finger slid across the surface, a linear relationship between the friction force and the contact area of the finger was observed. The slope of this approximately linear relationship was taken as the shear strength of the interface. The results demonstrated that the shear strength decreased as the film thickness of the coating on the Si surface increased; thus, the interfacial state of the solid was the dominant factor in determining the friction characteristics of the finger pad.

DOI： 10.2474/trol.11.396

DOI： 10.1016/j.triboint.2019.02.023_references_DOI_3ER7re7C7CxB92i4tHweURAcnmR

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その他リンク： https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-25420082/

記述言語：英語   出版者・発行元：Japanese Society of Tribologists  

The influence of roughness orientation on the friction-speed characteristics of adsorbed films was investigated by changing the angle of the anisotropically striated roughness to the sliding direction of the counter surface. As the angle of the striated roughness becomes perpendicular to the sliding direction, the friction coefficient is decreased. The friction-speed characteristics of the adsorbed film in the transverse direction of the striated roughness having different height or shape of asperities were also investigated. The friction coefficient obtained in the low speed region decreased with increasing arithmetic mean peak curvature (S_pc) when stearic acid-formulated oil was used as a lubricant oil. The results demonstrated that the roughness orientation and the asperity shape of the transverse roughness were key factors for generating additional load-bearing pressure so that the adsorbed films could exert their intrinsic friction-reducing effects.

DOI： 10.2474/trol.11.140

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記述言語：英語   出版者・発行元：Japanese Society of Tribologists  

The final target of this study is to discover the concert effect between ZnDTP and ashless FMs (polar compounds) that improve friction reducing performance together with keeping the good antiwear performance of ZnDTP. Evaluation of tribological performance and ZnDTP tribofilm formation were performed with a ball-on-disk type rolling-sliding tribometer. The tribofilm generated on the disk was analyzed by FT-IR analysis, Auger Electron Spectroscopy (AES) and Electron Probe Micro Analysis (EPMA). It was found that amino compounds showed a blocking effect, in which the ZnDTP tribofilm formation was prevented and the friction coefficient increased, whereas carboxyl compounds showed a concert effect, in which the friction coefficient was reduced with maintaining ZnDTP tribofilm formation.

DOI： 10.2474/trol.11.417

DOI： 10.2474/trol.19.228_references_DOI_McgZnN5q5KCxnuQYYJ0xhRuEc6m

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出版者・発行元：Elsevier BV  

Abstract Although the molybdenum dithiocarbamate (MoDTC) additive results in superior friction-reducing performance for both steel and diamond-like carbon (DLC) surfaces, it sometimes causes wear acceleration of DLC surfaces. This study confirmed the wear acceleration of a DLC surface lubricated with MoDTC-formulated oil. Three types of DLCs with different hydrogen contents were used. The nominal hydrogen contents of DLCs were hydrogen-free (ta-C), 10 at% (a-C:10H) and 30 at% (a-C:30H). The DLC coatings were deposited on a tool steel substrate. It was confirmed that MoDTC accelerated the wear of hydrogenated DLCs, although the formulation of MoDTC showed good friction-reducing performance for every specimen. To confirm the tribological characteristics of the other Mo-containing compounds for DLC lubrication, friction tests were carried out with several types of Mo-containing additives and their related Mo-free organic compounds. When the hydrogenated DLCs were lubricated with Mo-containing additives, the wear of the hydrogenated DLCs was accelerated. However, the hydrogenated DLCs did not show wear acceleration when lubricated with the related Mo-free organic compounds. The DLC surfaces after the friction test with Mo-containing additives were analyzed by X-ray photoelectron spectroscopy, and the MoO3 formation was confirmed on every specimen. Although the wear behavior was considered in relation to MoO3 formation on the worn surface to determine whether MoO3 plays a key role in accelerating the wear of DLC, apparent relationship between the wear acceleration and the MoO3 formation was not obtained.

DOI： 10.1016/j.triboint.2014.04.037

DOI： 10.2474/trol.12.123_references_DOI_MVpWcZ75gK74bFnFujTPexoobMX

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記述言語：英語   出版者・発行元：The Society of Chemical Engineers, Japan  

Typical FRP composites have a high chemical resistance and ease of construction, they have been widely used in chemical plants for applications such as chemical storage tanks. Accidental failures of a chemical tank roof were reported after the tank had been in service less than its expected lifetime. Therefore, comprehensive study of a composite material’s durability over a wide range of temperatures is proposed in this research. By using cyclic temperature of a solution condition, specimen is exposed into a chemical and the temperature is changed, a specimen in a liquid phase may change temperature along with the liquid; however, when a specimen is immersed in a vapor phase, the specimen may not change temperature with the vapor causing temperature difference and dew condensation inside of the material. After conducting bending tests of specimens at various immersion times under cyclic temperature of H₂SO₄ solution (nonvolatile acid), the strength of specimen in the vapor phase of H₂SO₄ showed a little bit lower than the specimen in the liquid phase, which contrasts with the results of specimen under isothermal condition that material strength in the liquid showed more damaged than in the vapor. Moreover, the H₂SO₄ concentration in the vapor is relatively low and the strength is in good agreement with the previous study using pure water under cyclic temperature of solution condition. This evident indicate the impact of the dew condensation on the strength which take place during temperature change. The cross-section of the specimen immersed in the vapor phase under cyclic solution temperature was chosen at the location, where microvoids are found. In general, cracks can easily initiate from microvoids that significantly affect the strength of the specimen. This experimental study is aimed to explain the mechanism of the roof failure and make a recommendation for the new design of FRP chemical tank.

DOI： 10.1252/jcej.14we320

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その他リンク： https://ndlsearch.ndl.go.jp/books/R000000004-I027013300

記述言語：英語  

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その他リンク： https://ndlsearch.ndl.go.jp/books/R000000004-I027052027

出版者・発行元：Springer Science and Business Media LLC  

The lubrication performance of imidazolium-based ionic liquids was evaluated under high vacuum using a ball-on-disk tribometer. A ball and a flat disk made of SUS440C stainless steel were used as specimens. A surface of the as-received flat disk specimen was covered with a thick oxide layer (>40 nm). For an examination of the effect of the surface oxide layer on the tribological performance of the ionic liquids under high vacuum, another specimen with a thin oxide layer (approx. 4 nm thick) was prepared. The ionic liquids with the TFSA anion showed better lubrication performance with the thicker oxide layer specimen, whereas the ionic liquids with the BF4 anion showed superior performance with the thinner oxide layer specimen. These results are discussed based on the HSAB principle. It is shown that the mechanism of the opposite tribological characteristics can be reasonably explained in terms of the chemical hardness by the HSAB principle.

DOI： 10.1007/s11249-014-0353-9

DOI： 10.2474/trol.10.91_references_DOI_Vvp27dS6vcZbXS02FDbkWTKFWH6

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その他リンク： http://link.springer.com/article/10.1007/s11249-014-0353-9/fulltext.html

出版者・発行元：Springer Science and Business Media LLC  

This work reports anisotropic water transport in a polymer composite consisting of an epoxy matrix reinforced with aligned triangular bars made of vinyl ester. By gravimetric experiments, water diffusion in resin and polymer composites were characterized. Parameters for Fickian diffusion and polymer relaxation models were determined by least-square curve fitting to the experimental data. Diffusion parameters of epoxy and vinyl ester resin were used as input during development of finite element (FE) model of polymer composite. Through transient FE diffusion analysis, anisotropic water transport in thickness direction of the polymer composite was numerically predicted and validated against experimental results. The case of using impermeable triangular bars was also numerically simulated. The diffusivity of reinforced aligned triangular bars was confirmed to affect anisotropic water transport in the composite. The results of this work suggest possible use of polymer composite for barrier and fluid removal applications.

DOI： 10.1007/s12034-014-0620-2

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出版者・発行元：Elsevier BV  

Abstract The use of touch panel displays has been increasing due to the popularity of tablet PCs and smart phones. In order to protect the touch panel surface from scratches, contaminants from fingerprints and skin oils and so on, anti-contamination coating is necessary. One of the ways to protect the surface is to cover it with a thin and dense organic molecular layer. At the present time, the primary requirement for the coating is fingerprint-resistance or easy removal of contaminants. An adsorbed molecular layer of PFPE-derivatives is currently used for this purpose, in order to reduce the surface energy of the surface. Since the current major concern of panel makers is anti-fingerprint performance, degradation of the molecular layer by both tribological and environmental conditions is a major issue for the development of the coatings. Given the current priorities, however, tribological research into such subjects as the touch feeling of the panel and the friction characteristic has not been conducted. The touch feeling and its relation to the operation are very important but very difficult to study because it is very hard to express the touch feeling numerically. As a preliminary study, several different coated surfaces were prepared and their friction coefficients were measured by rubbing with a finger or a steel or glass ball to clarify the tribological characteristics of the surface. An Si wafer and a glass plate were used in this study as models of the solid substrate of a display. They were coated with an adsorbed organic molecular layer of two PFPE-derivatives with different molecular structures named Type-F and Type-D or several reference molecular layers, such as OTS-SAM and FDTE-SAM. In addition to the tribological data, degradation by UV irradiation was also examined to compare the performance. The results are discussed from the tribological and chemical points of view.

DOI： 10.1016/j.triboint.2013.01.019

DOI： 10.1587/transele.2024dii0007_references_DOI_LvcITvo0NJO2DkOWlxQKyZyHq7i

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出版者・発行元：Springer Science and Business Media LLC  

The tribological performance of two types of additives—alkylated phenyl phosphate and lead naphthenate—dissolved in multiply-alkylated cyclopentane was evaluated under a high vacuum using two types of ball-on-disk tribometers: a reciprocating motion tribometer under mild loading conditions and a unidirectional rotating motion tribometer under heavy loading conditions. A ball and a flat disk made of SUS440C stainless steel were used as specimens for both tribometers. The surface of the as-received flat disk specimen was covered with a thick (>40 nm) oxide layer. For the examination of the effect of the surface oxide layer on the tribological performance of the liquid lubricants under a high vacuum, another specimen with an oxide layer (approx. 4 nm thick) was prepared. The alkylated phenyl phosphate additive showed better lubrication performance with the specimen with the thicker oxide layer, but the lead naphthenate additive showed superior performance with the thinner oxide layer specimen. It is also shown that these opposite tribological characteristics are explained by the hard and soft acids and bases principle.

DOI： 10.1007/s11249-013-0152-8

DOI： 10.2474/trol.10.138_references_DOI_ERFKIuwoiBQtrKN86c9Y7b5fpjT

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その他リンク： http://link.springer.com/article/10.1007/s11249-013-0152-8/fulltext.html

出版者・発行元：Elsevier BV  

Abstract This paper demonstrates the superior friction-reducing properties of organic polymer having multiple-point adsorption sites. Multiple-point adsorptive polymers showed higher transition temperature at elevated temperature experiments than the single-point adsorptive polar compounds due to their lower desorption property. It was found that the transition temperature of multiple-point adsorptive polymers increased with an increase in polarity of the base oils. This was due to the intrinsic tendency of the polymer chains to expand more in higher polarity solvents, which resulted in the polar groups of the polymers facing toward the friction surface to produce more adsorption sites.

DOI： 10.1016/j.triboint.2012.06.001

DOI： 10.2474/trol.17.246_references_DOI_DePYapDefuSIgG86uR46B1J9p5o

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掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

Abstract The friction-reducing effect of an adsorbed film at transverse roughness was investigated by focusing on the adsorption ability of polar compounds. Gradual reduction in friction under the low speed condition in case of the adsorbed film is formed from stearic acid or polymethacrylate. This is probably because the friction-reducing effect varied according to the adsorption ability and the number of the functional group. The results implied that the friction-reducing effect could be explained not only by the micro-EHL effect derived from transverse roughness but also by some other load-bearing effect, which depends on the formation state of the adsorbed film.

DOI： 10.1016/j.triboint.2012.10.003

DOI： 10.2474/trol.19.228_references_DOI_O9SmnsjZgwPvjFxVFG5vkVv13fn

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掲載種別：研究論文（学術雑誌）  

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出版者・発行元：SAGE Publications  

<jats:p> This work investigated water diffusion in composites consisting of a permeable matrix reinforced with aligned, impermeable, triangular elements. The triangular elements are expected to induce single axis-, filler orientation-dependent transport behaviour in the composite. Such property is suggested to be useful in slow barrier applications and fast drying processes. To test this idea experimentally, triangular bar-reinforced composite specimens are prepared using thermosetting plastics as representative components. Using water as model diffusant, specimens undergo absorption-desorption-reabsorption gravimetric experiments at 80°C. It is observed that diffusivity decreases when the base side of the reinforced triangular bars is exposed to diffusion and increases when it is the sloped side. Diffusion is also reduced when the triangular bars are in staggered alignment. </jats:p>

DOI： 10.1177/096369351202100601

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記述言語：英語   出版者・発行元：MATERIALS LIFE SOCIETY, JAPAN  

We investigated the influence of fillers on the deterioration of polyoxymethylene resin (POM) in ozone generated by electric discharge. The extent of deterioration was evaluated by studying the weight and thickness changes, three-point flexural strength, appearance and molecular weight of the resin. The weight and thickness of the material linearly decreased after the incubation period ; each surface gradually roughened by chalking. Flexural strengths are decreased with decrease in exposed time. Size exclusion chromatography measurements indicated that the degradation of POM by ozone proceeded via corrosion-layer formation and was limited to layers near the specimen surface, whereas the inner layer showed barely any deterioration. The corrosion rate was estimated from the thickness of the corrosion layer and residual thickness of the uncorroded layer. The flexural strength after exposure could be predicted from this estimated corrosion rate. In this study, even after adding fillers, no significant delay was observed in resin deterioration by ozone.

DOI： 10.11338/mls.24.95

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その他リンク： https://ndlsearch.ndl.go.jp/books/R000000004-I024071508

出版者・発行元：Universitas Gadjah Mada  

<jats:p>Vinyl ester resins are utilized for long-term corrosion protection of metal, alloy, and concrete substrates against concentrated acids, alkalis, and solvents at high temperature. Glass flakes are usually added as fillers to reduce chemical diffusion within the vinyl ester matrix. A common industry practice is to use glass flakes with large aspect ratio, high volume fraction, and in parallel alignment to surface in chemical contact for barrier applications. During processing and curing of glass flake-filled vinyl ester resins, irregular microstructures such as reduced flake aspect ratio and random orientation of flakes are commonly observed. Such microstructures can affect the overall chemical diffusion, resulting to barrier properties less predictable by simple diffusion models. Therefore, in this study, a simple 2D random walk simulation procedure is used in attempt to estimate the microstructural dependency of diffusion in glass flake-reinforced vinyl ester resins. While the random walk simulations are in good agreement with the tortuosity-based diffusion models in terms of microstructural effects, in most cases the simulation results are inconsistent with the experimental measurements of acid diffusion in glass flake-filled vinyl ester resins. A possible cause for this is the poor adherence of vinyl ester resin to glass flakes. Osmotic cracks are also formed during immersion which also influences overall diffusion through the material.</jats:p>

DOI： 10.22146/ajche.49751

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出版者・発行元：Hindawi Limited  

<jats:p>The aims of this study, firstly, to obtain high degree of clay exfoliation in the epoxy matrix by three dispersion methods such as normal mixing, shear mixing, and high-speed mixing and, secondly, to investigate corrosion behavior of epoxy/organoclay nanocomposite, immersion test, weight change, and penetration behavior were conducted. From the three mixing methods, the high-speed mixing method showed larger clay interlayer distance, smaller clay aggregate, and more homogeneity and expectedly resulted in high anticorrosive properties. Penetration depths of these nanocomposites showed a small difference; however, the most noticeable improvements in anticorrosion performance for epoxy/organoclay nanocomposites under high-speed mixing method were found to reduce penetration and weight uptake which are described via the model of nanoparticulate-filled structure and discussed in corrosion protection mechanism against environmental liquid penetration.</jats:p>

DOI： 10.1155/2012/924283

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記述言語：日本語   出版者・発行元：一般社団法人 色材協会  

アセタールコポリマー（Co-POM）の硝酸（HNO₃）水溶液下における腐食挙動を調査し，重量，寸法，色，曲げ強さと分子量の変化から劣化度合いを評価した。浸漬後の試料表面は白から黄色に変化し，重量変化は潜伏期間を経て減少を示した。純水浸漬後の曲げ強度は、乾燥によってほぼ初期強度まで回復したが，HNO₃水溶液に浸漬した試料では乾燥後も強度は回復しなかった。サイズ排除クロマトグラフィー測定から，HNO₃水溶液によるCo-POMの劣化進行は試料表面付近に限定され，試料内部ではほとんど劣化は観測されなかった。腐食速度は腐食層の厚みから計算でき，それを用いることにより浸漬後の未腐食部の厚みと残存曲げ強度が予測できることを示した。これら検討から，NHO₃水溶液によるCo-POMの劣化進展は腐食層形成型であった。

DOI： 10.4011/shikizai.85.138

DOI： 10.4139/sfj.72.704_references_DOI_YmBu0yo7kJRxdN1NVcMG89llnet

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その他リンク： https://ndlsearch.ndl.go.jp/books/R000000004-I023739299

記述言語：英語   出版者・発行元：The Society of Materials Science, Japan  

Flake-polymer composites are commonly used in protection and barrier applications due to its low effective diffusivity. Effective diffusivity through flake-polymer composites depends on the local accelerated transport along the flakematrix interphase. This paper describes analytical models for predicting the effective diffusivity through the flake-polymer composite as a function of flake orientation, volume fraction, aspect ratio, and interphase properties. Estimates of effective diffusivity were also generated using random walk simulations. Results from the two methods agree well with each other. Using model-predicted effective diffusivities, solute penetration depths in systems with flakes aligned either orthogonal or parallel to the diffusion direction are calculated and compared to experimentally obtained penetration depths of acid solutes through glass flake-polymer composites.

DOI： 10.2472/jsms.61.860

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その他リンク： https://ndlsearch.ndl.go.jp/books/R000000004-I024046713

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.triboint.2010.02.001

DOI： 10.1016/j.triboint.2016.02.025_references_DOI_9vykmHnrQg5dM6zXjCbCqoiJhAY

Web of Science

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記述言語：英語  

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その他リンク： https://ndlsearch.ndl.go.jp/books/R000000004-I11099635

出版者・発行元：Department of Chemical Engineering, Universitas Gadjah Mada  

Ortho-type UP resin is reinforced with long abaca and short bagasse fibers to produce a novel type of natural fiber-reinforced (NFR) hybrid composite material that is environment-friendly, has a long service life, possesses the properties of both long and short FRP’s, and has also acquired the advantages of utilizing two different types of natural fiber reinforcements. The abaca and bagasse fibers are treated in 5wt% NaOH(aq) solution at 80°C for 9 hours and pressed into continuous, unidirectional fiber sheets and random fiber mats, respectively. The fibers are then incorporated into the resin matrix by hand lay-up method, producing FRP laminates with the same uniform thickness but subjected to varying fiber loading conditions: (1) the stacking of long fiber sheets are done in cross-ply and parallel orientation; (2) the abaca and bagasse fibers are stacked in different alternating sequence patterns, and (3) the fibers are added into the ortho-UP matrix at increasing fiber fraction. The alkali-treated FRP laminates show an increase in fiber-matrix interfacial adhesion as compared to the untreated FRP’s, based on the overall improvement in the composite mechanical strength, as well as from the lesser visible fiber pull-out observed from SEM images on their fracture surfaces. Also, as expected, the tensile and flexural strengths of the abaca/bagasse hybrid FRP measures intermediate to those of abaca and bagasse FRP’s. The strength has also improved with increasing fiber content, although this increase has also caused an increased occurrence of void spaces that may consequently become detrimental to the NFR composite’s performance.

DOI： 10.29037/ajche.v1i0.245

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出版者・発行元：Wiley  

<jats:title>Abstract</jats:title><jats:p>A novel tribometer that undergoes significant changes at ultra‐slow (>5.0 µm s<jats:sup>−1</jats:sup>) to moderate (<20 cm s<jats:sup>−1</jats:sup>) sliding speeds was developed in order to study the friction‐speed characteristics of steel lubricated with oil. Three different surface topographies were applied to the specimens, and the friction characteristics with an additive‐free base oil (MO91) and a stearic acid‐formulated oil (StA/MO91) were studied to understand the effects of surface textures on the lubrication performance of an adsorbed molecular layer formed by StA. Friction reduction behaviour of the adsorbed layer observed in the transverse direction was attributed to microscopic hydrodynamic action that maintained the load‐carrying performance of the adsorbed layer. Copyright © 2010 John Wiley & Sons, Ltd.</jats:p>

DOI： 10.1002/ls.114

DOI： 10.1016/j.triboint.2012.10.003_references_DOI_1PpsbRDS3rdBllTMYSdZA9rxauy

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出版者・発行元：SAGE Publications  

<jats:p> Phosphorous (P) ion implantation was performed on a steel substrate to investigate the effect of the P implantation on the friction characteristics of steel lubricated with oil. To determine the characteristics of the P-implanted layer, several kinds of surface analyses were carried out, resulting in a correlation between the X-ray photoelectron spectroscopy depth profile and the thickness from spectroscopic ellipsometer. A three balls-on-disc tribometer was employed with sliding speeds ranging from 3 mm/s to 40 cm/s. The friction coefficient of the P-implanted steel was relatively lower at speeds below 10<jats:sup>−1</jats:sup> m/s, compared with the unimplanted steel. This could account for both the sacrificing nature and the adhesion behaviour of the P-implanted layer. </jats:p>

DOI： 10.1243/13506501jet714

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掲載種別：研究論文（学術雑誌）  

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掲載種別：研究論文（学術雑誌）  

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掲載種別：研究論文（国際会議プロシーディングス）  

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掲載種別：研究論文（国際会議プロシーディングス）  

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掲載種別：研究論文（学術雑誌）  

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.tsf.2008.06.084

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Japanese Society of Tribologists  

In order to estimate the wear process of diamond-like carbon (DLC) films, a ball on disk test and a micro laser Raman spectroscopy are employed in this study. DLC films are deposited on high-speed tool steel (JIS-SKH51) surfaces by a plasma based ion implantation and deposition (PBII&D). After the ball on disk test with a steel ball (JIS-SUJ2) as an indenter, a mapping measurement using micro laser Raman spectroscopy has been accomplished against both the wear surface of the DLC films and the surface of the indenter. As a result, obvious changes in the structure of the DLC films originating from the contact interface between the substrate and the indenter are observed. This is like to be caused by the graphitization of the DLC films. On the other hand, except for the preceding descriptions, the Raman spectra are almost same to each other and there are no changes in the structure of the DLC films. This means that the effects of the sliding on the changes in the structure can be neglected. In addition, the carbon compounds and the solid solutions of carbon and iron included in the substrate and the indenter hardly influence the Raman spectra with or without sliding.

DOI： 10.2474/trol.3.110

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記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：The Surface Finishing Society of Japan  

Carbon ions were implanted into hardened high-speed tool steel by means of a plasma immersion ion implantation (PIII) technique with methane gas. Various process times were used in order to investigate the relationship between mechanical properties and depth distribution of carbon, and to examine whether it is possible to apply PIII for practical use for commercialized high-speed tool steel substrate. The implanted surface was characterized by X-ray diffractmeter (XRD) for investigation of surface structure. Auger electron spectroscopy (AES) was used to determine the depth distribution profile of the elements in substrate. Raman spectroscopy was also utilized for the characterization of carbon film deposited on the substrate. Substrate temperature was estimated from the hardness of a tool steel substrate treated simultaneously. Substrate temperature did not exceed the tempering temperature of high-speed tool steel, and was below 532K. Short term implantation with −20kV of negative bias caused a high concentration of carbon at the steel surface. On the other hand, carbon film was deposited on the carbon enriched surface by long term implantation. Raman spectrum for the deposited carbon film showed that for a typical DLC film. Friction test with a bearing steel ball as a counter material was similar to that the friction coefficient of deposited DLC film, carbon implanted layer, and steel substrate were 0.2, 0.3 and over 0.5, respectively. These results suggest that PIII with methane is feasible for the surface treatment of high-speed tool steel as both the implanted carbon and the DLC film reduce its friction coefficient in dry conditions.

DOI： 10.4139/sfj.59.185

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その他リンク： https://jlc.jst.go.jp/DN/JALC/00310916121?from=CiNii

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Japanese Society of Tribologists  

Based on the demand of extremely increased area density for magnetic data storage, the contact recording systems have been proposed, in which stronger and thinner hard coatings and lubricant films for the head disk interface (HDI) are desired. In this study, two lubrication methods, i.e., the vacuum vapor deposition and dip-coating methods are evaluated and compared in order to satisfy the demands from the HDI development. Perfluoropolyether (PFPE) is applied to the diamond-like carbon (DLC) surface. The advantage of the vacuum vapor deposition is to prevent contamination of the DLC surface from the atmosphere because of no exposed samples to the atmosphere. In contrast, the advantage of dip-coating method is to thicken the bonded layer of the PFPE by heat treatment. We discuss the adsorption mechanism between the PFPE molecules and DLC surface for each method. In addition, a simple reaction model based on the Arrhenius equation is developed and compared to the experimental results. We concluded that the reaction will be dominated by covalent bonds and hydrogen bonding. Furthermore, the reaction model can well express the experimental results. The remarkable destruction of the DLC film by the heat treatment are not seen in the samples heat treated at a temperature from 353 to 423 K while the remarkable destruction are seen in the samples treated from 423 to 473 K.

DOI： 10.2474/trol.3.259

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.triboint.2007.01.006

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記述言語：英語  

DOI： 10.4271/2007-01-1989

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1243/13506501JET132

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1080/05698190590965558

DOI： 10.1016/j.triboint.2012.10.003_references_DOI_O0n8Ugr20gmzWnclsDiGHsIteB1

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

DOI： 10.1016/s0167-8922(03)80192-x

DOI： 10.1016/j.triboint.2012.10.003_references_DOI_DBNwiAwkSKlbavgeeeF3bwFawfx

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記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmeicm.2014.summer.5

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記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2014._s1720105-

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記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmeicm.2013.5

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記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2013._s172016-1

DOI： 10.3323/jcorr.72.121_references_DOI_M7hbVOh4vtqm3aDNMFq6j27t995

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記述言語：日本語   出版者・発行元：学校法人 金沢工業大学 材料システム研究所  

DOI： 10.34401/zairyosystem.31.0_37

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その他リンク： https://ndlsearch.ndl.go.jp/books/R000000004-I024417989

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記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmeicm.2013.autumn.9

DOI： 10.3323/jcorr.72.121_references_DOI_6oltyC8CUNWYZaaJGOJQAus8WyX

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記述言語：日本語   出版者・発行元：公益社団法人 腐食防食学会  

アセタールコポリマー (Co−POM)の硝酸(HNO₃)水溶液下における腐食機構とそのモデル化について検討を行った．劣化度合は，質量および分子量変化によって評価した．硝酸水溶液における質量変化は，潜伏期間後に直線的に減少した．SEC測定結果から，HNO₃水溶液によるCo-POMに対する腐食は表面近傍を主体に進展し，内部は初期状態を維持していたことから，その腐食形態は腐食層形成型と一致した．加水分解反応によるCo-POMの腐食速度式は，試料表面の分子量低下から得た反応速度定数を用いて算出した．次に，質量変化(湿潤−乾湿試料)を用いて，HNO₃水溶液のCo−POM内への拡散係数を求め，これによって得られる試料内の経時的な濃度分布変化と先の腐食速度式を組み合わせることにより，Co−POMの腐食速度を数値解析により求めた．解析結果と実験結果はおおむね良好な一致を示し，この手法で速度論的なモデル化を行うことが可能であることを示した．

DOI： 10.3323/jcorr.61.182

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その他リンク： https://ndlsearch.ndl.go.jp/books/R000000004-I023691458

記述言語：日本語   出版者・発行元：公益社団法人 日本材料学会  

DOI： 10.2472/jsms.61.537

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その他リンク： https://ndlsearch.ndl.go.jp/books/R000000004-I023847424

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecj.2012._s172011-1

DOI： 10.3323/jcorr.72.121_references_DOI_IOVj1CxZ9rgwKALwLbjvlxj4vqC

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記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmeicm.2011.15

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記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmeicm.2009.7

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記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmekanto.2008.14.45

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記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmeibaraki.2007.253

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記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

DOI： 10.1299/jsmemecjo.2002.5.0_155

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