Article
Engineering, Mechanical
Motoyuki Murashima, Shintaro Oyama, Hiroyuki Kousaka, Takayuki Tokoroyama, Woo-Young Lee, Noritsugu Umehara
Summary: In this paper, a new in situ low-friction technology for diamond-like carbon coatings using surface discharge in ambient air was developed. The friction coefficient decreased significantly after surface discharge, and surface analysis showed the effectiveness of surface discharge in creating a thick and soft transfer layer for optimal low friction conditions. The study also highlighted the importance of low-energy surface discharge design in producing a thick transfer layer with low friction.
TRIBOLOGY INTERNATIONAL
(2022)
Article
Chemistry, Multidisciplinary
Kang Wang, Jie Zhang, Tianbao Ma, Yanmin Liu, Aisheng Song, Xinchun Chen, Yuanzhong Hu, Robert W. Carpick, Jianbin Luo
Summary: Diamond-like carbon films exhibit superlubricity at nanocontacts through a two-stage running-in process, involving mechanical removal of oxide layer and structural ordering transformation. This results in a significant decrease in friction, providing insights into friction evolution mechanisms and criteria for superlubricity design.
Article
Engineering, Mechanical
Wenjun Wu, Motoyuki Murashima, Tomohiro Saso, Takayuki Tokoroyama, Woo-Young Lee, Hiroyuki Kousaka, Noritsugu Umehara
Summary: In this paper, a new in situ surface treatment technology for diamond-like carbon (DLC) coatings using dielectric barrier discharge (DBD) in ambient air is developed. The friction coefficient decreased significantly after DBD irradiation, especially when gas containing humidity and oxygen was blown to the DBD discharge position, a superlow friction was observed. Only nitrogen-containing DLC coatings formed a liquid film with DBD irradiation, resulting in superlow friction due to the interaction of developed soft organic material and highly acidic liquid.
TRIBOLOGY INTERNATIONAL
(2022)
Article
Engineering, Mechanical
E. Humphrey, V Elisaus, R. Rahmani, M. Mohammadpour, S. Theodossiades, N. J. Morris
Summary: This paper investigates the driving range concession due to parasitic frictional losses in a two-stage battery electric vehicle transmission caused by gear mesh. The use of thin wear resistant coatings such as DLC and changes in surface roughness are considered to reduce these losses. The analysis shows that the investigated amorphous hydrogenated undoped DLC coating could potentially save 1.1 km of vehicle range during extra urban driving and 0.9 km under urban driving over a full battery discharge cycle.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Materials Science, Multidisciplinary
Katarzyna Piotrowska, Monika Madej, Joanna Kowalczyk, Krystyna Radon-Kobus
Summary: This study evaluates the effects of surface roughness on the properties of a-C:H:Si coatings obtained through plasma-assisted chemical vapor deposition (PACVD). The results show that the adhesion strength of the coatings on polished surfaces is higher compared to sandblasted surfaces, leading to improved friction and wear parameters.
Article
Materials Science, Coatings & Films
Sukanta Bhowmick, Shayan Shirzadian, Ahmet T. Alpas
Summary: This study shows that incorporating titanium atoms into the structure of diamond-like carbon coatings can reduce the coefficient of friction and lessen running-in wear. Therefore, Ti-H-DLC exhibits good friction behavior at elevated temperatures and is suitable for manufacturing processes with high friction requirements.
SURFACE & COATINGS TECHNOLOGY
(2022)
Article
Chemistry, Physical
Kun Sun, Xue Fan, Lei Yang, Sicheng Chen, Jinwei Fan, Dongfeng Diao
Summary: The research on GNC film shows that it has high electrical conductance and short run-in period, effectively reducing energy consumption and presenting promising practical applications.
APPLIED SURFACE SCIENCE
(2021)
Article
Chemistry, Physical
Fiona M. Elam, Feng-Chun Hsia, Stefan van Vliet, Roland Bliem, Liuquan Yang, Bart Weber, Steve E. Franklin
Summary: Corrosion affects the nanoscale topography and friction response of a hydrogenated amorphous carbon film (a-C:H), with surface oxidation identified as the main cause of increased friction force and surface adhesion. The highest friction coefficient was observed for the film corroded at 2.5 V, attributed to jagged surface topography promoting an interlocking friction mechanism.
Article
Materials Science, Ceramics
Guomin Yu, Zhenxi Zhang, Pei Tian, Zhenbin Gong, Junyan Zhang
Summary: By depositing MoS2 flakes on H-DLC film using drop-casting process, a composite structure was obtained, and the results showed that MoS2 flakes effectively suppressed energy dissipation and reduced friction during the sliding process. Superlow friction at macro-scale could be achieved in air with a relative humidity of 24 ± 2%, indicating that the introduction of MoS2 flakes led to the evolution of carbon transfer film/hydrogenated diamond-like carbon contact into a self-organized and highly ordered MoS2 transfer film/hydrogenated diamond-like carbon heterogeneous contact, resulting in significant reduction of friction during rubbing period.
CERAMICS INTERNATIONAL
(2021)
Article
Chemistry, Physical
Rob Brittain, Tomasz Liskiewicz, Ardian Morina, Anne Neville, Liuquan Yang
Summary: In this study, DLC-GNP nanocomposite films with various GNP coverages were synthesized and the effect of GNP coverage on the mechanical properties and tribological response of the films was investigated. The study showed that with increasing GNP coverage, both friction and wear of the DLC-GNP nanocomposites decreased.
Article
Materials Science, Coatings & Films
Mahdi Khadem, Dae-Eun Kim
Summary: The study assessed the friction and wear behaviors of SKH51 steel at low temperatures with both bare and DLC/Cr bi-layer coatings, finding that the bi-layer coating significantly reduced wear, especially at low temperatures, with the formation of a thin layer of frozen water playing a key role in determining wear behaviors.
SURFACE & COATINGS TECHNOLOGY
(2021)
Article
Chemistry, Physical
Jae-Il Kim, Woo-Young Lee, Takayuki Tokoroyama, Noritsugu Umehara
Summary: Diamond-like carbon (DLC) is a promising solid lubricant, but its friction behavior with iron-and brass-based metals is inferior compared to titanium alloys. This study aims to improve the friction performance of DLC by modifying the contact interface from Fe/C to C/C through Ti addition. It is found that Ti promotes the development of carbon transfer on Fe-based counterpart and enhances the friction performance of DLC sliding against Fe by forming a thick carbonous transfer layer.
Article
Engineering, Mechanical
Yunhai Liu, Lei Wang, Ting Liu, Peng Zhang
Summary: The study found that the friction and wear behaviors of DLC film are not only related to the friction pairs but also related to the normal loads, showing different characteristics under different friction pairs.
Article
Materials Science, Multidisciplinary
Jiawei Yao, Fuyao Yan, Hongtao Chen, Baofeng Chen, Mufu Yan, Yanxiang Zhang
Summary: A gradient composite layer consisting of a hardened nitrided layer and a self-lubricating DLC structure was fabricated on M50 steel surface via plasma-assisted thermochemical treatment. The layer showed functionally graded hardness profile and excellent wear resistance.
MATERIALS & DESIGN
(2022)
Article
Materials Science, Ceramics
Nur Aszreen Zulkifli, Shahira Liza, Hiroki Akasaka, Kanao Fukuda, Nur Adilah Mohd Rawian, Nur Afieqah Md Ghazazi, Noor Ayuma Mat Tahir, Yazid Yaakob
Summary: Using pulse current and DLC flakes can improve the surface quality and durability of hard anodizing. Increasing the DLC content enhances the hardness and wear resistance of the oxide film, while using 5 g/L DLC in the electrolyte reduces friction.
CERAMICS INTERNATIONAL
(2023)
Article
Engineering, Mechanical
Motoyuki Murashima, Shintaro Oyama, Hiroyuki Kousaka, Takayuki Tokoroyama, Woo-Young Lee, Noritsugu Umehara
Summary: In this paper, a new in situ low-friction technology for diamond-like carbon coatings using surface discharge in ambient air was developed. The friction coefficient decreased significantly after surface discharge, and surface analysis showed the effectiveness of surface discharge in creating a thick and soft transfer layer for optimal low friction conditions. The study also highlighted the importance of low-energy surface discharge design in producing a thick transfer layer with low friction.
TRIBOLOGY INTERNATIONAL
(2022)
Review
Engineering, Mechanical
Shuaihang Pan, Kaiyuan Jin, Tianlu Wang, Zhinan Zhang, Long Zheng, Noritsugu Umehara
Summary: This review systematically summarizes the fabrication and processing techniques of metal matrix nanocomposites (MMNCs) in tribology, investigates the important factors determining their tribological performance, and provides a (semi-)quantitative description of the mechanisms behind improved anti-friction and anti-wear performance. It also discusses the potential applications of MMNCs in various fields and explores the potential development of modeling, experimental, and theoretical techniques in MMNCs' tribological processes.
Article
Engineering, Mechanical
T. Tokoroyama, Y. Tagami, M. Murashima, W-Y Lee, N. Umehara, H. Kousaka
Summary: The hardness of amorphous carbon nitride was improved by incorporating tantalum through ion beam assisted filtered arc deposition, resulting in low friction coefficient and specific wear rate in ambient air. Different coatings were prepared by varying nitrogen flow and discharge cycles of tantalum. Surface and wear scar analysis revealed that the ta-C:Ta200 coating exhibited the lowest friction coefficient and specific wear rate, which may be attributed to the presence of amorphous Ta2O5 and the desorption of oxygen from the coatings.
TRIBOLOGY INTERNATIONAL
(2022)
Article
Engineering, Mechanical
Yusei Yamada, Motoyuki Murashima, Noritsugu Umehara, Takayuki Tokoroyama, Woo-Young Lee, Hajime Takamatsu, Yoshikazu Tanaka, Yoshiharu Utsumi
Summary: This study demonstrates the influence of fracture properties and surface morphology on the wear properties of diamond-like carbon (DLC) coatings. The results indicate that the wear rate of rough DLC coatings decreases with increasing fracture toughness, while that of smooth DLC coatings is independent of fracture toughness.
TRIBOLOGY INTERNATIONAL
(2022)
Article
Engineering, Mechanical
Wooyoung Lee, Motoyuki Murashima, Noritsugu Umehara, Takayuki Tokoroyama, Norihisa Horaguchi, Takao Ishimoto
Summary: This study focused on the friction behavior of tetrahedral amorphous carbon nitride in hydrofluorocarbon (HFC) refrigerant, and found that it exhibited good friction characteristics under difluoromethane and polyolester mixture environment.
TRIBOLOGY INTERNATIONAL
(2022)
Article
Engineering, Mechanical
Jae-Il Kim, Woo-Young Lee, Takayuki Tokoroyama, Motoyuki Murashima, Noritsugu Umehara
Summary: This study aimed to investigate a suitable mating material against diamond-like carbon coatings, and found that titanium has the lowest coefficient of friction, making it an ideal mating material.
TRIBOLOGY INTERNATIONAL
(2022)
Article
Engineering, Mechanical
Wenjun Wu, Motoyuki Murashima, Tomohiro Saso, Takayuki Tokoroyama, Woo-Young Lee, Hiroyuki Kousaka, Noritsugu Umehara
Summary: In this paper, a new in situ surface treatment technology for diamond-like carbon (DLC) coatings using dielectric barrier discharge (DBD) in ambient air is developed. The friction coefficient decreased significantly after DBD irradiation, especially when gas containing humidity and oxygen was blown to the DBD discharge position, a superlow friction was observed. Only nitrogen-containing DLC coatings formed a liquid film with DBD irradiation, resulting in superlow friction due to the interaction of developed soft organic material and highly acidic liquid.
TRIBOLOGY INTERNATIONAL
(2022)
Article
Engineering, Chemical
T. Tokoroyama, K. Tanaka, T. Kani, M. Murashima, W-Y Lee, N. Umehara, T. Oshio, K. Yagishita
Summary: The tribological properties of a-C:H coating sliding against different counterparts were investigated with the presence of additives in a temperature range. The additives contained glycerol and hydroxyl functional groups to enhance the interaction with a-C:H coating and form a phosphorus oxide tribolayer. XPS depth analysis suggested the dissociation of additives and C-O bond cleavage.
Article
Nanoscience & Nanotechnology
Swapnil Ghodke, Motoyuki Murashima, Dennis Christy, Ngo Van Nong, Kenji Ishikawa, Osamu Oda, Noritsugu Umehara, Masaru Hori
Summary: The mechanical properties, including compressive strength and modulus, of the maze-like CNW structure synthesized by RI-PECVD technique were analyzed using nanoindentation method, revealing an elastoplastic behavior.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Engineering, Mechanical
Jae-Il Kim, Takayuki Tokoroyama, Motoyuki Murashima, Noritsugu Umehara, Woo-Young Lee
Summary: Diamond-like carbon (DLC) is a promising solid lubricant with excellent anti-friction and wear-resistance characteristics. This study investigates the wear behavior of counterparts sliding against DLC. The findings suggest that wear of transition metals is mainly due to oxidative wear, and the wear is prevented by carbon-containing tribofilms transferred from DLC.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Engineering, Mechanical
Y. Nakashima, N. Umehara, H. Kousaka, T. Tokoroyama, M. Murashima, D. Mori
Summary: This study aimed to suppress silica adhesion on geothermal power generator equipment by using diamond-like carbon (DLC), which resulted in a significant reduction in the adhered silica amount. The optimal DLC structure to reduce silica adhesion was determined to be reducing the sp2 bond fraction and increasing the hydrogen content of the outermost surface of DLC, although there was no correlation with the surface energy. This suggests that silica adhesion has a different mechanism from conventional adhesion.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Engineering, Chemical
Y. Nakashima, N. Umehara, H. Kousaka, T. Tokoroyama, M. Murashima, K. Murakami
Summary: The study found that DLC coatings with low sp(2) fractions and high hydrogen contents can suppress silica adhesion, and further experiments confirmed that silica adheres to defective graphene-like networks. First-principles calculations showed that graphene with hydrogen-terminated defects had reduced adsorption energy between silica and the graphene-like network. Through simulations and experiments, a silica adhesion model was established where defects in the graphene-like network of DLC behave as silica adhesion sites.
Article
Engineering, Mechanical
Huiyi Yang, Yang Xu, Chao Xu
Summary: This study focuses on the impact of dry friction interfaces on the dynamics of jointed structures, particularly on the statistics of contact pressure distribution. Through experimental and simulation analysis, it is found that surface roughness and contact load have significant effects on contact area, contact stiffness, and mean contact pressure.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
(2024)
Article
Engineering, Mechanical
Guanglan Hu, Houfu Dai
Summary: The effect of metal coating on the machinability of cubic silicon carbide was investigated using molecular dynamics simulation. The results showed that the type of coating has a significant impact on cutting force, surface morphology, stress, and tool wear. Among the three metals studied, Cu coating had the greatest impact on improving cutting performance.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
(2024)
Article
Engineering, Mechanical
Yunfan Liu, Guozheng Ma, Lina Zhu, Cuihong Han, Zhen Li, Bin Zhang, Haichao Zhao, Haidou Wang, Shuying Chen
Summary: The service performance of coated self-lubricating spherical plain bearings can be improved by applying self-lubricating coatings, especially double-sided coatings. The presence of a large-area and complete mixed friction transfer film on the contact surfaces can cause a signal downstage before the signal mutation stage.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
(2024)
Article
Engineering, Mechanical
Yakup Artun, C. Oktay Azeloglu, Gokhan Taylan
Summary: This article investigates the tribological properties of polymer journal bearings, particularly focusing on radial journal bearings made from UHMWPE and POM materials with different surface qualities. The study examines the performance of these bearings under varying load and speed conditions, and analyzes the relationship between material and surface roughness in tribological performance.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
(2024)
