| Project/Area Number |
02555152
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| Research Category |
Grant-in-Aid for Developmental Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
金属材料(含表面処理・腐食防食)
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| Research Institution | Osaka University |
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Principal Investigator |
SHIBATA Toshio Osaka University, Faculty of Engineering. Professor, 工学部, 教授 (90001205)
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| Co-Investigator(Kenkyū-buntansha) |
KOBAYASHI Minoru Mitsubishi Electric Co., Research Institute for production Engineering, Principa, 生産技術研究所加工技術部, 主幹
NAGANO Hiroo Sumitomo Metals, Co., R & D. Div., Principal Research Manager, 研究開発本部, 研究主幹
FUJIMOTO Shinji Osaka University, Faculty of Engineering, Assistant., 工学部, 助手 (70199371)
TANIGUCHI Shigeji Osaka University, Faculty of Engineering, Associate Professor, 工学部, 助教授 (50029196)
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| Project Period (FY) |
1990 – 1991
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| Project Status |
Completed (Fiscal Year 1991)
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| Budget Amount *help |
¥12,200,000 (Direct Cost: ¥12,200,000)
Fiscal Year 1991: ¥6,100,000 (Direct Cost: ¥6,100,000)
Fiscal Year 1990: ¥6,100,000 (Direct Cost: ¥6,100,000)
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| Keywords | Laser / Electrochemical Reaction / Microscopy / Localized corrosion / Fine Image Etching / レ-ザ-励起電解 / 粒界腐食 / レ-ザ-めっき / レ-ザ-セッティング / 微細加工法 |
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| Research Abstract |
For evaluation of localized corrosion susceptibility, metallography for structure or composition, and laser etching/plating, a Scanning Laser Enhanced Electrochemical Microscopy (SLEEM) has been developed. Solid state semiconductor laser of AlGaAs which is small and easily controlled was used as a scanning laser source. In 1990, a 40 mW output power type laser was used and later 80 mW type was introduced in 1991. Laser out put was Chopped by bias voltage into 10 Hz to 100 Hz square wave and irradiated to the metal specimen which is kept at a constant potential in the electrolytic solution. Change in electrolytic current by laser irradiation is detected by a lock in amplifier and make a scanning image by using microcomputer. Current change induced by laser irradiation at the constant potential is found to be proportional to the electrolytic current without irradiation. Decrease in frequency of irradiation induces the current increase because of temperature increase at the metal surface as a theoretical model predicts. Characteristic increase in current for Fe, Cr and Ni which are constituents elements of stainfess steels was observed at a specified potential region for each element, so that current change of stainless steel by irradiation at the constant potential depends on its composition. Resolving power of the SLEEM is the same size of about 10 mum as the spot size of the laser beam. Based on the above analysis, the chromium depleted grain boundary image of sensitized stainless steel could be obtained succesfully at the potential that is active for Fe but passive for Cr. At the trans passive potential, the compositional image of Cr in two phase stainless steel could be obtained. Fine image etching can be made at the active and transpassive potential.
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