| Project/Area Number |
10450271
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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 | Osaka University |
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Principal Investigator |
HIRATA Yoshinori Graduate School of Eng., Osaka University, Associate Professor, 大学院・工学研究科, 助教授 (00116089)
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| Co-Investigator(Kenkyū-buntansha) |
URAGAKI Hiroshi Faculty of Education, Kochi University, Professor, 教育学部, 教授 (10107138)
OHJI Takayoshi Graduate School of Eng., Osaka University, Professor, 大学院・工学研究科, 教授 (00089880)
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| Project Period (FY) |
1998 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥9,200,000 (Direct Cost: ¥9,200,000)
Fiscal Year 1999: ¥4,300,000 (Direct Cost: ¥4,300,000)
Fiscal Year 1998: ¥4,900,000 (Direct Cost: ¥4,900,000)
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| Keywords | Micro-Arc / Electrical breakdown / Micro materials processing / Very small size welding / Tungsten cathode / Melting and evaporation process / グロー放電 / 微細加工 / アーク溶棲 / 溶融・蒸発現象 / アーク溶接 |
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| Research Abstract |
The phenomena associated with micro-arc, which is struck in argon gas atmosphere in the gap between thin tungsten cathode and stainless steel plate anode, were experimentally investigated. The experimental setup, which is consisted of a micro-arc torch, precise positioning mechanisms actuated by piezoelectric devices and pulse motors, and a power supply for discharge, was constructed. Time-resolution of micro-discharge appearance was observed through microscope with high-speed shutter CCD camera. The results obtained are summarized as follows :
(1) Electrical breakdown voltage increases with increase of gap length beyond about 10μm. In the range of small gap length of a few micrometer, it requires almost constant voltage of 250-300 V independently of gap length. High intense luminous region of micro-arc is concentrated at the electrode tip in the early stage of the discharge and then expands with time.
(2) The size and/or the form of melting spot at anode surface by micro-arc depend mainly on gap length. Melting spot with flat surface having diameter of 5-10μm can be obtained by adjusting gap length, current level and pulse width.
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