| Project/Area Number |
17360362
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Material processing/treatments
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| Research Institution | Fukui National College of Technology |
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Principal Investigator |
YASUMARU Naoki Fukui National College of Technology, Mechanical Engineering, Professor (90158006)
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| Co-Investigator(Kenkyū-buntansha) |
MITAZAKI Kenzo Kyoto University, Institute of Advanced Energy, Professor (50293957)
KATO Hirotaka Fukui National College of Technology, Mechanical Engineering, Professor (30311020)
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| Project Period (FY) |
2005 – 2007
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| Project Status |
Completed (Fiscal Year 2007)
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| Budget Amount *help |
¥11,910,000 (Direct Cost: ¥11,400,000、Indirect Cost: ¥510,000)
Fiscal Year 2007: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
Fiscal Year 2006: ¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 2005: ¥6,500,000 (Direct Cost: ¥6,500,000)
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| Keywords | femtosecond laser / ablation / hard thin film / DLC / nanostructure / scanning probe microscope / tribology / トライボロジ-特性 / トライポロジー特性 |
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| Research Abstract |
We report tribological properties of diamond-like carbon (DLC) film of which surface has been nanostructured with femtosecond (fs) laser pulses. A broad area on the DLC surface was nanostructured using a precise target-scan system developed for the fs-laser processing. In the present experiment we have developed two types of laser scan. One is a parallel scan to produce a uniformly nanostructured surface. The other is a crossed scan along a net-like pattern to form a partially nanostructured area on the surface. The results obtained are summarized as follows.
1) The nanostructure has been formed uniformly on the DLC surface over the area of 15 x 15 mm^2.
2) The structured surface at E=110μJ near the ablation threshold is uniformly modified to the GC layer.
3) The friction coefficient of the structured DLC film has shown a small decrease for the steel ball but a small increase for the ceramic WC-Co ball.
4) A large improvement of the friction coefficient of the DLC surface has been achieved by coating the MoS2 layer on the nanostructured DLC surface. The measured friction coefficients μ of the surface were 0.07 with the steel ball and 0.02-0.04 with the WC-Co ball.
5) The net-like patterning of the ablated zone created by the crossed scan produces an effective method to increase maintaining the initial surface flatness.
6) The nano-indentation test and nano-scratch test (100〜2000μN) indicate that the laser-treated surface layer modified to GC becomes soft and its friction coefficient increases as compared with that of the untreated DLC.
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