A5060762148- Lubricants and Their Additives
- Diamond and Carbon-based Materials Research
- Tribology and Wear Analysis
- Metal and Thin Film Mechanics
- Tribology and Lubrication Engineering
- Advanced ceramic materials synthesis
- Advanced materials and composites
- Force Microscopy Techniques and Applications
- Electric and Hybrid Vehicle Technologies
- Radiative Heat Transfer Studies
- Gear and Bearing Dynamics Analysis
- High-Temperature Coating Behaviors
- Advanced Combustion Engine Technologies
- Vehicle emissions and performance
- Vibration and Dynamic Analysis
- Adhesion, Friction, and Surface Interactions
- Powder Metallurgy Techniques and Materials
- Mechanical Failure Analysis and Simulation
- Intermetallics and Advanced Alloy Properties
- Mechanical stress and fatigue analysis
- Advanced Materials Characterization Techniques
- Synthesis and properties of polymers
- Real-time simulation and control systems
- Advanced Machining and Optimization Techniques
- Catalytic Processes in Materials Science
Utsunomiya University
2019-2024
Nissan (Japan)
1999-2020
Nissan (United Kingdom)
1995-2018
Nissan (United States)
2000-2007
We report a unique tribological system that produces superlubricity under boundary lubrication conditions with extremely little wear. This is thin coating of hydrogen-free amorphous Diamond-Like-Carbon (denoted as ta-C) at 353 K in ta-C/ta-C friction pair lubricated pure glycerol. To understand the mechanism vanishing we performed ToF-SIMS experiments using deuterated glycerol and 13C was complemented by first-principles-based computer simulations ReaxFF reactive force field to create an...
ZnDTP antiwear additive for lubricating oil is known to absorb strongly on sliding surfaces in boundary lubricated tribosystems, forming a tribofilm, which able reduce the wear of involved surfaces. It also increase friction coefficient most DLC/DLC contacts, with exception ta-C DLC / contact, difference behaviors between base + tribosystem and not very significant. In this study we investigate characterization method shape tribofilm formed different types coatings relation behavior related...
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 hydrogenated amorphous (a-C:H) DLC when it is rubbed steel counterpart material boundary lubrication. Chromium reported decrease due increase activation energy. In this research, we investigated effects friction properties a-C:H Cr plating material. Results...
Graphene oxide (GO) and reduced graphene (rGO) are known to exhibit low friction when dispersed in water or oil, although the underlying mechanism is not yet fully understood. In this study, five GO rGO powders were used for tests dispersion. The structure of (Raman spectrometry), bonding state carbon (XPS analysis), secondary particle size (dynamic light scattering) measured clarify effects these factors on dispersibility coefficient. results revealed that smaller size, higher...
The first piston ring application of a hydrogen-free diamond-like carbon (H-free DLC) coating to mass-production gasoline engine reduces friction. It is found that the friction reduction effect between cylinder bore and 18%. When H-free DLC applied top ring, over 10% reduced. larger than oil rings. Because as low effective in thin film there are few at large area near Top Dead Center (TDC). enhanced when lower viscosity used. In this study, adhesion strength on rings also improved. shown...
The use of diamond-like carbon (DLC) coatings in engine components can be one the potential solutions for automotive industry to improve fuel efficiency by controlling friction and wear. tribological behavior various types DLC liquid lubricated systems their interaction with lubricants are needed proper usage these coatings. In this study, wear performance four different synthetic base oil polyalpha-olefin (PAO) were investigated using pin-on-disc tribometer under boundary condition. One...
Friction tests were conducted with a direct-acting automotive valvetrain to evaluate the effect of axial cross-sectional shape cam on friction using various shapes from concave convex. The results revealed that levels could be understood as function contact ratio between and mating valve lifter regardless shape. A flat high was found have lowest level friction. Compared convex-shaped same height, tended show higher because lower lifter. finite element method (FEM) calculations also showed...
Abstract Belt‐drive continuously variable transmissions are already being increasingly used in Europe and Japan for small vehicles, but midsize vehicles will require greater torque capacity. This paper discusses the effect of ZDDP as an additive on increasing traction obtained at sliding interfaces between elements pulleys a belt‐drive transmission (B‐CVT). stems from higher friction coefficient interfaces. Friction coefficients were measured rig tests which test pieces cut actual CVT slid...
This paper discusses the effect of zinc-dialkyldithiophosphate (ZDDP) additive on increasing friction obtained at sliding interfaces between elements and pulleys a belt-drive continuously variable transmission (B-CVT). Rig tests were performed with different types CVT fluid to verify ZDDP additive. The surface roughness film formation was also examined. increases coefficient due adsorbed surface. A quantitative correlation seen amount Zn contained in as measure B-CVT torque capacity. Under...