2002 Fiscal Year Final Research Report Summary
| Project/Area Number |
12640374
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
物性一般(含基礎論)
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| Research Institution | OSAKA UNIVERSITY |
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Principal Investigator |
MATSUKAWA Hiroshi Graduate School of Science, Osaka Univ., Associate Professor, 大学院・理学研究科, 助教授 (20192750)
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| Co-Investigator(Kenkyū-buntansha) |
KAWAGUCHI Takaaki Faculty of Education, Shimane Univ., Associate Professor, 教育学部, 助教授 (10273913)
TATARA Gen Graduate School of Science, Osaka Univ., Research Assistant, 大学院・理学研究科, 助手 (10271529)
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| Project Period (FY) |
2000 – 2002
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| Keywords | Friction / Pinning / Lubricaiton / Charre Density Wave / Flux Lattice / Tribology / Nanotechnology / Nanomachine |
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| Research Abstract |
Sliding friction between two solid surface is an important issue in our daily life and has been investigated from ancient age. Investigation of friction in micro and nano scales starts recently and attracts much attention. Frictional phenomena similar to the sliding friction between two solid surface are observed in solids, such as pinning and dynamics of density waves and magnetic flux lattice. These various frictional phenomena have many common properties but also particularities. Physics of these phenomena is not clear even in fundamental aspects.
In this research project we studied frictional phenomena of various scales, attempt to understand them in a unified way and make clear the universality and variety of friction by employing effective model suitable to each scale of frictional phenomena. We got the following results.
i) We investigated the 2-dimensional model, in which all atoms in one solid are fixed, and obtained the following results.
The direction of motion can deviate from
… More
that of the external force.
Randomness can make small the frictional force.
The system has a peculiar order, the so called Bragg glass.
The system in motion has finite static frictional force against the external force perpendicular to the motion.
ii) We developed an effective model, which describes the behavior of the lubricant molecule by means of their density fluctuation. Based on the model we discovered a novel phenomena in which the enhancement of crystal order of the lubricant molecules diminishes the frictional force.
iii) Graphite is one of the most important solid lubricants with small frictional coefficient. By numerical simulation of the friction of graphite flakes and graphite substrate we reproduced the small frictional coefficient observed in experiments and made clear its mechanism. We also explained the load-dependence of the frictional force microscope experiment of graphite.
iv) Various frictional phenomena can be expressed by elastic manifold model with pinning. The effects of plasticity is, however, can not be taken into account in the model. By detailed analysis of the model which take into account the effects of plasticity, we made clear peculiar behavior of the effects and its mechanism. Less
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Research Products
(13 results)
