研究者詳細 - 梅原　徳次

論文 - 梅原　徳次

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Development of Surface Roughness Generation Model for CFRTP Manufactured by LFT-D 査読有り国際誌

Murashima Motoyuki, Murooka Takaharu, Umehara Noritsugu, Tokoroyama Takayuki

INTERNATIONAL JOURNAL OF AUTOMATION TECHNOLOGY 14 巻 ( 2 ) 頁： 208 - 216 2020年3月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：富士技術出版株式会社

In this study, we propose a new surface generation model for carbon fiber reinforced thermoplastics (CFRTP) manufactured by the long fiber thermoplastic-direct (LFT-D) method. CFRTP are considered to be a next-generation structural material because of their high productivity as well as high mechanical strength and lightness. Conversely, CFRTP have a rough surface, which does not meet the automotive outer panel standard of a “class A surface.” In the present study, we establish a surface roughness generation model based on a thermal shrinkage mismatch of thermoplastic resin to carbon fiber and non-uniform carbon fiber distribution. Furthermore, we construct a surface roughness estimation formula based on the model. In the calculation, a cross-sectional image of CFRTP is divided into many vertical segments. Subsequently, the thermal shrinkage of each segment is calculated with a standard deviation, an average, and a probability density of the amount of carbon fiber in each segment. The surface roughness of the manufactured CFRTP was measured using a surface profilometer. The result showed that the arithmetic surface roughness increased with the volume fraction of carbon fiber. We applied the surface roughness calculation to cross-sectional images of the specimens. Consequently, the estimated surface roughness showed the same tendency, in which the surface roughness increased with the volume fraction of carbon fiber. The slope of a regression line of the estimated surface roughness with respect to the volume fraction was 0.010, which was almost the same (0.011) as the slope of a regression line of the measured surface roughness. Furthermore, the estimation formula using a thermal shrinkage effective depth of 395 μm was able to estimate the surface roughness within a 3% average error. Using the estimation formula, it was predicted that the surface roughness increased with the standard deviation of the amount of carbon fiber in a segment. To confirm the reliability of the model and the formula, we measured the standard deviation of the amount of carbon fiber in CFRTP specimens, showing that the trend for CFRTP specimens matched the estimated values.

DOI： 10.20965/ijat.2020.p0208

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CiNii Research

Effect of Mating Material and Graphitization on Wear of a-C:H Coating in Boundary Base Oil Lubrication 査読有り国際誌

Aboua Kouami Auxence Melardot, Umehara Noritsugu, Kousaka Hiroyuki, Tokoroyama Takayuki, Murashima Motoyuki, Bin Mustafa Mohd Muhyiddin Bin, Mabuchi Yutaka, Higuchi Tsuyoshi, Kawaguchi Masahiro

TRIBOLOGY LETTERS 68 巻 ( 1 ) 頁： 24 2020年1月

担当区分：最終著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Tribology Letters

Hydrogenated amorphous carbon (a-C:H) coating exhibits different wear behaviors depending on its counterpart material in boundary lubricated sliding contact. In previous works, tribological behaviors of a-C:H coating were investigated against steel, chromium, and germanium counterpart materials. The specific wear rate of a-C:H coating was found to decrease with the ability of its counterpart material to react with or dissolve carbon. The present study investigated how graphitization of a-C:H coating's top layers and interactions of the counterpart material with carbon influence wear behaviors of a-C:H coating in boundary lubrication. Results show that a-C:H coating shows graphitization of its top layers regardless the counterpart material. Correlation with differences in wear behaviors of the a-C:H coating leads to the conclusion that graphitization will induce high wear of a-C:H coating only when there are also atomic interactions between the DLC coating and its counterpart material.

DOI： 10.1007/s11249-019-1248-6

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EFFECTS OF LUBRICATION CONDITION ON FRICTION AND WEAR IN OIL LUBRICATION FOR ALUMINIUM ALLOY BEARINGS WITH VARIOUS CARBONACEOUS HARD COATINGS

Umehara Noritsugu, Kitamura Tomoki, Tokoroyama Takayuki, Murashima Motoyuki

7TH INTERNATIONAL CONFERENCE INTEGRITY-RELIABILITY-FAILURE (IRF2020) 頁： 1045 - 1046 2020年

グリセリン及びリン酸骨格構造を有する添加剤によるa-C:H膜の潤滑油中トライボロジー特性

蟹拓実, 野老山貴行, 梅原徳次, 村島基之, 八木下和宏

年次大会 2020 巻 ( 0 ) 頁： S11311 2020年

"FRICTIONLESS" DIAMOND-LIKE COATINGS AND IN-SITU OBSERVATION USING REFLECTANCE SPECTROSCOPY

Umehara, N

7TH INTERNATIONAL CONFERENCE INTEGRITY-RELIABILITY-FAILURE (IRF2020) 頁： 7 - 8 2020年

The Surface Enhanced Raman Scattering Analysis for Carbonaceous Coating by Using Au Nano-Particles 査読有り

Tokoroyama Takayuki, Murashima Motoyuki, Umehara Noritsugu

TRIBOLOGY ONLINE 15 巻 ( 5 ) 頁： 300 - 308 2020年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：一般社団法人日本トライボロジー学会

In general, Raman analysis is one of the useful candidates to obtain structure of carbonaceous coatings. To improve the depth resolution of Raman analysis, surface-enhanced Raman Scattering (SERS) using gold nanoparticles (Au nanoparticles: AuNPs) and Au sputtered particles were investigated. The analysis was conducted to approximately 1.7, 2.4, 4.7, and 10.0 nm thickness of carbon coatings on silicon substrate with a 532 nm incident wavelength laser. The results indicated that the underlying silicon substrate was detected in the results of the Au sputtering method. Contrastingly, the underlying silicon substrate was not detected by the AuNPs method. This result clarified that using the AuNPs method, the detection depth of the carbon film was approximately 1.7 nm or less. The a-C:H coating was processed using a calotester, and SERS measurements at different depths were performed for the 633 and 532 nm wavelengths using the AuNPs method. As a result, the IG peak position tended to increase from the vicinity of the inter face between the a-C:H coating and the substrate to the surface. In addition, the ID/IG ratio was as low as 0.28 near the substrate and 0.72 at 3800 nm.

DOI： 10.2474/trol.15.300

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CiNii Research

ta-CNx膜の摩擦摩耗特性に及ぼす膜中又は摩擦相手材タンタルの影響査読有り

北條孝樹, 梅原徳次, 野老山貴行, 村島基之

日本機械学会論文集 86 巻 ( 888 ) 頁： 20-00018 - 20-00018 2020年

コーティング電気メス先端の炭化物付着抑制手法の開発査読有り

野老山貴行, 小林将大, 村島基之, 梅原徳次, 小川航生, 萬隆行, 内田淳一

日本機械学会論文集 86 巻 ( 889 ) 頁： 20-00273 - 20-00273 2020年

二液分離油の反射分光摩擦面その場観察装置を用いたしゅう動部油膜その場分析査読有り

山田高澄, 梅原徳次, 野老山貴行, 村島基之, 佐藤卓, 大原健司, 羽生田清志

日本機械学会論文集 86 巻 ( 884 ) 頁： 19-00315 - 19-00315 2020年

ポリ塩化ビニル溶媒への交流電場援用マイクロプラスチック突起の創製査読有り

山田雄聖, 野老山貴行, 村島基之, 梅原徳次

日本機械学会論文集 86 巻 ( 892 ) 頁： 20-00228 - 20-00228 2020年

ディーゼルエンジンオイル中ナノメートルサイズPMの交流電場による凝集を用いたろ過手法の開発査読有り

野老山貴行, 柴沢穂高, 梅原徳次

日本機械学会論文集 86 巻 ( 884 ) 頁： 20-00016 - 20-00016 2020年

Intelligent tribological surfaces: from concept to realization using additive manufacturing 査読有り国際誌

Murashima Motoyuki, Yoshino Shouta, Kawaguchi Masato, Umehara Noritsugu

INTERNATIONAL JOURNAL OF MECHANICS AND MATERIALS IN DESIGN 15 巻 ( 4 ) 頁： 757 - 766 2019年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：International Journal of Mechanics and Materials in Design

In this paper, we provide a detailed account of our efforts in the design, development and prototyping of a novel intelligent surface by adapting initially curved diaphragms. Unlike the shortcomings that characterize current designs of functional surfaces, our adaptive surface design is characterised by simplicity, multifunctionality, adaptability, high flexibility and robustness as well as controlled autonomy. Four aspects of the work are accordingly examined. The first is concerned with the conceptual design of the new functional surface. The second with the development of functional prototypes of intelligent surfaces, showing its characteristics and ease of manufacturing using 3D additive manufacturing. The third with demonstrating the multi-frictional ability of the newly designed surface. Our friction test results show wide range friction control ability from the friction coefficient value 0.3 (same value of material itself) to 3 times higher value 1.1. Finally, we address the challenges that are faced in our new design and the efforts that are currently being adopted to overcome them.

DOI： 10.1007/s10999-018-9435-4

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Investigating running-in behavior to understand wear behavior of ta-C coating with filtered cathodic vacuum arc deposition 査読有り国際共著国際誌

Lee Woo-Young, Tokoroyama Takayuki, Murashima Motoyuki, Umehara Noritsugu

JURNAL TRIBOLOGI 23 巻頁： 38 - 47 2019年12月

Effect of Carbon Diffusion on Friction and Wear Behaviors of Diamond-Like Carbon Coating Against Germanium in Boundary Base Oil Lubrication 査読有り国際共著国際誌

Aboua Kouami Auxence Melardot, Umehara Noritsugu, Kousaka Hiroyuki, Tokoroyama Takayuki, Murashima Motoyuki, Mabuchi Yutaka, Higuchi Tsuyoshi, Kawaguchi Masahiro

TRIBOLOGY LETTERS 67 巻 ( 2 ) 頁： 65 2019年6月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Tribology Letters

Diamond-like carbon (DLC) coatings are designed to work under severe lubrication conditions. Depending on working environment, lubrication condition, and counterpart material, DLC coatings can exhibit crucial variations in their tribological behaviors. In the search of a counterpart material to improve tribological performances of DLC coatings in desired environment, we found out in previous work that carbon diffusion is an important parameter that influences the tribological behaviors of amorphous hydrogenated (a-C:H) coating in boundary lubrication. a-C:H coating exhibits high wear against steel counterpart material that has a high carbon affinity/solubility, while its exhibits lower wear against chromium counterpart material that has lower carbon affinity/solubility than steel. These recent findings imply that consideration of the carbon affinity/solubility when choosing a counterpart material for a-C:H coating in boundary lubrication might be of significant importance to improve tribological performances of a-C:H coating. This research investigates tribological behaviors of a-C:H coating against germanium counterpart material that has extremely low carbon affinity/solubility. Results show that there is no atomic interaction between a-C:H coating and germanium during friction and wear test, followed with a very low wear of a-C:H coating.

DOI： 10.1007/s11249-019-1179-2

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The tribological potential of graphene growth from solid waste 査読有り国際共著

Noor Ayuma Mat Tahir, Fakulti Kejuruteraan Mekanikal, Mohd Fadzli Bin Abdollah*, Noreffendy Tamaldin, Hilmi Amiruddin, Mohd Rody Bin Mohamad Zin, Takayuki Tokoroyama and Noritsugu Umehara

Progress in Industrial Ecology – An International Journal 13 巻 ( 4 ) 頁： 401 - 413 2019年4月

Effect of oxygen on degradation of defects on ta-C coatings deposited by filtered arc deposition 査読有り国際誌

Murashima Motoyuki, Deng Xingrui, Izuoka Hiroto, Umehara Noritsugu, Kousaka Hiroyuki

SURFACE & COATINGS TECHNOLOGY 362 巻頁： 200 - 207 2019年3月

担当区分：最終著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Surface and Coatings Technology

Among diamond-like carbon (DLC) coatings, tetrahedral amorphous carbon (ta-C) coatings show particularly high thermal stability and oxidation resistance due to their high sp 3 content and hydrogen-free structure. On the other hand, it is well known that high-temperature annealing leads to degradation of the ta-C structure, resulting in a release of stress, decrease of hardness, increase in surface roughness, and transformation of the coating nature. Although optical observation is a powerful candidate for imaging the surface conditions of ta-C coatings, strong light emission due to high temperature prevents the acquisition of clear images. In this paper, we establish a novel in situ observation method using environment scanning electron microscopy (ESEM), which allows us to view ta-C surface defects and droplets at 650 °C. A heater embedded in the ESEM increased the temperature on ta-C coatings to 650 °C at gas pressure of 120 Pa. Using a variety of gas conditions including ambient air, dry nitrogen, or dry oxygen, we clarified the effect of the gases on the degradation of the defects. In a dry oxygen atmosphere, defects grew dramatically with annealing time, whereas nitrogen caused no significant transformation to ta-C surfaces. Raman spectroscopy analysis revealed significant structural change in one type of defect, while no noticeable Raman shift was detected in the other type. A focused ion beam created a cross-section of an annealed defect on the ta-C coating. Subsequently, energy dispersive X-ray spectroscopy (EDS) revealed the characteristics of defect growth; one type of defect was associated with a droplet on the interlayer, and the other with graphitization due to oxidization of ta-C on the droplets.

DOI： 10.1016/j.surfcoat.2019.01.115

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Tribological properties of ta-CNx coating sliding against steel and sapphire in unlubricated condition 査読有り国際誌

Liu Xiaoxu, Umehara Noritsugu, Tokoroyama Takayuki, Murashima Motoyuki

TRIBOLOGY INTERNATIONAL 131 巻頁： 102 - 111 2019年3月

担当区分：最終著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Tribology International

Tribo-behavior of tetrahedral amorphous carbon nitride (ta-CNx) coating in unlubricated condition was investigated in this study. Sliding against steel, low nitrogen content ta-CNx exhibits much lower friction and wear as temperature increases, with less adhesion wear than ta-C and remained relatively higher hardness (45.01 GPa). Nevertheless, against sapphire ta-C outperforms ta-CNx greatly, and graphitization could be found at 120 °C. With atmosphere humidity increasing, ta-CNx shows significantly decreased friction, implying the tribo-character of high sp3 bonding structure. Meanwhile, dry air seems to be the harshest condition for ta-CNx, since O2 in the atmosphere might lead to oxidized wear of ta-CNx even under room temperature. Furthermore, in humid N2, as an inert gas with high humidity, ta-CNx shows the lowest friction and wear.

DOI： 10.1016/j.triboint.2018.10.022

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Processing thin (<10 mu m), dense, flexible alpha-Al2O3 films from nanopowders 査読有り国際共著国際誌

Takeuchi Makoto, Niedermaier Matthias, Jansohn Monika, Umehara Noritsugu, Laine Richard M.

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN 127 巻 ( 2 ) 頁： 81 - 89 2019年2月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：公益社団法人日本セラミックス協会

Normally, it is very difficult to process thin ceramic films (<10 ¯m) except by vapor deposition methods. This is because in traditional ceramics processing, initial powder particle sizes (typical average particle sizes, APSs >200 nm) make it difficult to realize mechanically robust thin films after sintering to full density due to excessive grain growth. One solution to this problem is to start with nanopowders (APSs <100 nm). Here we present efforts to use simple, easily available nano ¤-Al 2 O 3 (transition or t-Al 2 O 3 ) nanopowders (NPs) to process the subject films. Thus t-Al 2 O 3 NPs when properly dispersed, doped with 0.55 wt.% MgO and ball milled with a polymeric binder provide castable systems. Wire wound roller drawing/tape casting provides access to thin green films (1030 ¯m) with µ75 wt.% ceramic loadings. Following binder burnout and careful sintering to temperatures of up to 1500°C/7 h/air but preferably slightly lesser conditions leads to dense ¯10 ¯m films with average ¡-Al 2 O 3 grain sizes of 500800 nm. At higher MgO concentrations, spinel phase separates during sintering likely inhibiting grain growth. These relatively dense films are flexible and translucent. Such films, because of their flexibility, may offer utility as catalyst supports, electronic substrates or as hard facings for other materials.

DOI： 10.2109/jcersj2.18099

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ベース油中ta-CNx膜の摩擦時反射分光分析その場観察による低摩擦メカニズムの解明査読有り

岡本竜也, 梅原徳次, 野老山貴行, 村島基之

日本機械学会論文集 85 巻 ( 875 ) 頁： 19-00071 - 19-00071 2019年

Effect of Pillar and Mesh Structure of Tetrahedral Amorphous Carbon (ta-C) Coatings on the Wear Properties and Fracture Toughness of the Coating 査読有り国際共著国際誌

Bin Mustafa Mohd Muhyiddin, Umehara Noritsugu, Tokoroyama Takayuki, Murashima Motoyuki, Shibata Akinori, Utsumi Yoshiharu, Moriguchi Hideki

TRIBOLOGY ONLINE 14 巻 ( 5 ) 頁： 388 - 397 2019年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：一般社団法人日本トライボロジー学会

Wear by fracture is among the factors associated with the DLC coating failures in the tribological application. The current study investigated the link between the wear and the fracture-toughness on the novel Pillar and Mesh structure ta-C coatings, in addition to conventional ta-C coatings. The tribological properties of these coatings were examined under base-oil lubrication via ball-on-disk tribo-tester and micro indentation technique was used to characterize the fracture toughness. The wear track and the indentation mark were analyzed using the optical microscope, 3D laser microscope and FE-SEM. The friction coefficient for ta-C, Pillar ta-C and Mesh ta-C are within the range of 0.071 to 0.106. Mesh ta-C indicated the highest wear resistance, followed by the Pillar ta-C and conventional ta-C. Also, Mesh ta-C demonstrated the highest fractute‐toughtness value with 16.6 Mpa.m1/2, followed by pillar ta-c with 13.4 MPa.m1/2 in contrast to ta-C. Greater resistance to wear for ta-C with Pillar and Mesh structure was detected with an increased fracture-toughness and improvement in crack propagation inhibition. Moreover, the Pillar and Mesh ta-C provides superior rate of crack-energy dissipation as compared to the ta-C.

DOI： 10.2474/trol.14.388

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