Zobrazeno 1 - 10
of 459
pro vyhledávání: '"Noritsugu Umehara"'
Publikováno v:
Journal of Advanced Mechanical Design, Systems, and Manufacturing, Vol 18, Iss 3, Pp JAMDSM0032-JAMDSM0032 (2024)
Frost formation poses challenges in various sectors, impacting efficiency and safety. Active methods involve energy-consuming processes like heating, while passive approaches utilize protective coatings or hydrophobic surfaces to minimize frost aggre
Externí odkaz:
https://doaj.org/article/b4c27a3d321c47c2a4f32a3d75f7af0f
Publikováno v:
Tribology Online, Vol 18, Iss 6, Pp 292-301 (2023)
With the increasing demand for active friction control, we newly proposed to use dielectrophoresis to change the flow of PG-droplet-containing PAO4 to reduce the friction coefficient. The friction result with a 1-mm roller shows 20% reduction in fric
Externí odkaz:
https://doaj.org/article/22221220d53d42ecab35f22398cfaf14
Autor:
Yu Shinohara, Jae-Hyeok Park, Takeshi Hagio, Jae-Il Kim, Woo-Young Lee, Noritsugu Umehara, Ryoichi Ichino
Publikováno v:
Materials & Design, Vol 230, Iss , Pp 111938- (2023)
Despite the excellent performance of hard Cr plating using hexavalent chromium (Cr6+), its use is being restricted owing to recent environmental regulations. Electrodeposited Fe-W alloy is considered a possible alternative, but its high coefficient o
Externí odkaz:
https://doaj.org/article/95ef5cba45b141ee993e018ea0b08efb
Autor:
Takayuki Tokoroyama, Takashi Nishimoto, Yasuhiro Murakami, Akiyuki Honda, Hideaki Mitsui, Yusuke Terai, Motoyuki Murashima, Woo-Young Lee, Noritsugu Umehara
Publikováno v:
Tribology Online, Vol 16, Iss 4, Pp 255-262 (2021)
In this study, nano-scratch tests were conducted using atomic force microscope (AFM) to clarify the hardness of a tribofilm derived from an additive (Fluid A or Fluid B in automatic-transmission fluid) formed on an SKS3 cold work tool steel substrate
Externí odkaz:
https://doaj.org/article/4b734425d41e44b18a96764d7d94ec52
Autor:
Takumi Kani, Takayuki Tokoroyama, Noritsugu Umehara, Motoyuki Murashima, Woo-Young Lee, Kazuhiro Yagishita
Publikováno v:
Tribology Online, Vol 16, Iss 4, Pp 263-270 (2021)
In general, several mechanical parts are subjected to friction and wear. To prevent wear and high friction coefficient under lubrication, additives can work to reduce friction force, to build up thin film on surfaces which is so-called tribofilm. Rec
Externí odkaz:
https://doaj.org/article/c371dd94a7ba490481be6c839043baff
Autor:
Tatsuya Okamoto, Noritsugu Umehara, Motoyuki Murashima, Koji Saito, Kazuyoshi Manabe, Keiji Hayashi
Publikováno v:
Tribology Online, Vol 16, Iss 1, Pp 49-58 (2021)
To clarify the low friction mechanism of CNx coating in PAO oil lubrication, we measured reflectance spectrum at friction area in-situ by reflectance spectroscopy during friction test against a sapphire hemisphere pin in PAO oil. We observed and esti
Externí odkaz:
https://doaj.org/article/4d6056ec9edf43af9403342c0a04c22b
Publikováno v:
Tribology Online, Vol 15, Iss 5, Pp 300-308 (2020)
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) an
Externí odkaz:
https://doaj.org/article/52c4122a4b1c4aec8bf03805d2039357
Autor:
Mohd Muhyiddin Bin Mustafa, Noritsugu Umehara, Takayuki Tokoroyama, Motoyuki Murashima, Akinori Shibata, Yoshiharu Utsumi, Hideki Moriguchi
Publikováno v:
Tribology Online, Vol 14, Iss 5, Pp 388-397 (2019)
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,
Externí odkaz:
https://doaj.org/article/a158a631aa28426cb15860124c7095ce
Autor:
Kouami Auxence Melardot Aboua, Noritsugu Umehara, Hiroyuki Kousaka, Takayuki Tokoroyama, Motoyuki Murashima, Yutaka Mabuchi, Tsuyoshi Higuchi, Masahiro Kawaguchi
Publikováno v:
Tribology Online, Vol 13, Iss 5, Pp 290-300 (2018)
Investigations on tribological behaviors of Diamond-like Carbon (DLC) coating against other materials are strongly needed for scientific and industrial purposes. Recently, carbon diffusion has been found to play a key role in the wear of hydrogenated
Externí odkaz:
https://doaj.org/article/a75faa5d3b994e608c236d9e7360b515
Publikováno v:
Tribology Online, Vol 13, Iss 5, Pp 241-247 (2018)
In this paper, the tribological behaviors of 1 μm of tetrahedral amorphous carbon (ta-C) coatings deposited with a different substrate bias of -0 V, -100 V and -300 V are examined under elevated temperature up to 600°C. It is found that wear behavi
Externí odkaz:
https://doaj.org/article/58cb9a48811541de8d021ee4fdc35692