RESEARCH ON LIQUID FILM SURFACE FORCE CONFINED WITHIN NANO-METER SPACING AND ITS EFFECT ON SURFACE CONTACT
| Project/Area Number |
11650153
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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 |
設計工学・機械要素・トライボロジー
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| Research Institution | SAGA UNIVERSITY |
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Principal Investigator |
BO Zhang SAGA UNIVERSITY, FACULTY OF SCIENCE & ENGINEERING, ASSOCIATE PROFESSOR, 理工学部, 助教授 (60264678)
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| Project Period (FY) |
1999 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2001: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 2000: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1999: ¥2,000,000 (Direct Cost: ¥2,000,000)
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| Keywords | Nanotribology / Surface force / Laplace pressure / nano film / Meniscus / Micromachine / Magnetic Recording / Laplace pressure measurement |
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| Research Abstract |
The deformation of solid surfaces caused by the Laplace pressure is analyzed and its effect on the ^meniscus force measurement on a surface force apparatus is discussed. It is found theoretically that the deformation reaches several nano meter orders and reduces greatly the meniscus force when the meniscus curvature radius is small. It is concluded that the deviation of the measured meniscus force with the surface force apparatus from equation F=4πγRcosθ for nano meter meniscus may be neither due to the hydrogen bonding interaction, nor the short range solid-solid interaction. The main reason lies in the deformation of the solid surface due to the Laplace pressure. The nano meter deformation of solid surfaces caused by the Laplace pressure is of great importance in measurement of the meniscus force.
In addition to the surface deformation, van der Waals force is also considered as a contribution to the pull-off force. As a result, it is found that the pull-off force will depend greatly o
… More
n the vapor pressure around the solid surfaces.
As a solution to reduce the effects of solid surface deformation on the measurement of the pull-off force, a new method of direct measurement of the Laplace pressure was proposed, measuring device was designed, and measurement was conducted on the new device. Satisfactory agreement between the Experimental and theoretical results was obtained.
In addition to the basic studies mentioned above, the effect of surface force on the performance of slider air bearing of magnetic head in hard disc systems was analyzed with respect to the glide avalanche. The numerical results show that surface force reduces the stiffness of the slider air bearing and the load carrying capacity as well. It is worth noting that, although the decrease in the load carrying capacity may not be significant, the reduction in the stiffness may be critical for many cases. The reduction in the stiffness of slider air bearings due to the surface force may be one of the most important mechanisms of the glide avalanche. The predicted take-off height to overcome the surface force is about several nano-meters. Increasing the pitch angle tends to decreases the take-off height. A lubricant film of about 1 nm will reduce the risk of the glide avalanche in some extent, but increasing the film thickness has little effect. Less
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Report
(4 results)
Research Products
(10 results)
