Awarded Research Themes and Reports
Note: "Affiliation" in the table is based on the day of grant.
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| Grant Year | Research Theme | Principal Investigator, Co-Investigator (Country) |
Research Content Summary / Related Publication / Main Report |
|---|---|---|---|
| 2015 First |
Micro-scale Tribological Properties of Tribofilms Formed in Boundary Lubrication | Assoc. Prof. Renguo Lu (Japan) 15A10 |
Ⅰ. Summary Zinc dialkyl dithiophosphate (ZnDTP) and molybdenum dialkyl dithiocarbonate (MoDTC) form tribofilms at sliding interfaces and widely used as additives in automotive lubricants. The tribofilms are crucial for the management of wear and control of friction. In this research, the tribological failure of the tribofilms was studied by replacing the additive-containing oils with an additive-free oil during friction. The tribofilm generated from ZnDTP showed long duration while that from MoDTC was easily removed by friction. Friction coefficient distribution of a tribofilm was measured using a self-developed ball-on-disk friction tester. The friction distribution agreed well with the chemical images of the tribofilm, indicating that the friction depended on its chemical nature much more than the physical nature. By an in situ observation of tribofilm growth using a lateral force microscope (LFM), the formation of nano-stripped Mo-containing composites contributed to the low friction of the tribofilm while Zn-containing composites offered anti-wear properties when used with ZnDTP. Ⅱ. Related Publication (Researcher doesn't agree to disclose main report.) 15A10 Related Publication (HP).pdf Affiliation of Principal Investigator: Kansai University |
| Direct Measurement of Voltage-Controlled Friction between Graphene Sheets | Prof. SUSAN PERKIN (UK) 14B02 |
Ⅰ. Summary The direct control of friction and lubrication, using external parameters such as applied voltage, is highly desirable but not yet realized or well studied. With this project we implemented a technique, based on the Surface Force Balance, to measure surface forces including friction between two voltage-controlled surfaces across liquid films. The surfaces are graphene sheets, necessarily optically transparent to facilitate the interferometric measurement of liquid thickness down to nm resolution. The process for creating and transferring large area and smooth graphene sheets was improved and direct measurements of adhesion forces are reported. Electrical connections are set up and the voltage controlled experimnets are underway. Ⅱ. Main Report (including Related Publication) 14B02 Related Publication (HP).pdf Affiliation of Principal Investigator: University of Oxford |
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| Effects of wear on superhydrophobic surfaces: experimental and theoretical investigation | Prof. Michael Khonsari (USA) 14B09 |
Ⅰ. Summary Recent years have witnessed an explosion of interest in a class of surfaces with superhydrophobic properties that enable the fluid droplets to roll off the surface, thereby exhibiting a self-cleaning property with remarkable industrial potential. One of the most important factors that influences this magnificent property is the surface roughness, a tribological parameter that is strongly affected by during the running-in period—an extremely complex process wherein the surface roughness changes drastically with time. In this research, we developed a fundamental analysis for determining the evolution of roughness and contact angle. The results involved extensive analysis of plastic deformation of asperities to realistically characterize the variation of surface finish during the transient and steady wear. The results were used in the Cellular Potts model (CPM) simulation to predict how the contact angle changes with time. The results were experimentally verified using a disk-on-disk tribometer and a contact angle measurement device. Ⅱ. Related Publication (Researcher doesn't agree to disclose main report.) 14B09 Related Publication (HP).pdf Affiliation of Principal Investigator: Louisiana State University |
|
| 2015 Second |
Verifications of EHD lubricant rheological models with in-situ local flow measurements | Dr. Janet Wong (UK) 15B06 |
Ⅰ. Summary TTRF has contributed partly to the development of novel platform which allows local rheology of a lubricant in an Elastohydrodynamic lubrication conditions to be examined. Previous platform, consisted of a rotating ball rubbed against a stationary disc, only allows for pure sliding conditions at relatively low speeds. As a result only high viscosity fluids, which is not necessarily a good representative of common lubricants, can be studied. This, together with pure sliding test conditions, means results obtained may be strongly influenced by frictional heating. To overcome these shortcomings, a new test rig was designed and fabricated. The new platform allows the speed of the ball and the disc to be controlled independently. Higher entrainment speeds can be applied with sufficient stability for laser-based techniques to be applied for local lubricant rheological measurements. Pilot studies using commonly rheological fluids have been conducted. Preliminary results show the test rig works as intended. Ⅱ. Related Publication (Researcher doesn't agree to disclose main report.) 15B06 Related Publication (HP).pdf Affiliation of Principal Investigator: Imperial College London |
| Effect of lubricants on hydrogen embrittlement of steel | Prof. Joichi Sugimura (Japan), Dr. Monica Ratoi (UK) 15B10 |
Ⅰ. Summary The presence of hydrogen in the microstructure of steel rolling element bearings is a cause of their early catastrophic failure in extreme load applications. The hydrogen generation has been shown to be an important driver in the formation of characteristic white etching cracks in the sub-surface. Rolling-sliding experiments were conducted in three different environments, and hydrogen dissolved in steel is determined with TDS. It was found that hydrogen permeation in steel is strongly influenced by the base oil chemistry, where the formation of oxide film and water content played important roles. It was also found that hydrogen generation and permeation was prevented by some anti-wear agents added in the base oils through formation of reactive film on the steel. Ⅱ. Main Report (including Related Publication) 15B10 Main Report (HP).pdf Affiliation of Principal Investigator: Kyushu University |