| Project/Area Number |
02555018
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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 |
機械材料工学
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| Research Institution | Kyoto University |
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Principal Investigator |
KOMAI Kenjiro Department of Mechanical Engineering, Kyoto University, Professor, 工学部, 教授 (70025948)
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| Co-Investigator(Kenkyū-buntansha) |
ONO Masatoshi Advanced Technology Division, Electrotechnical Laboratory, Head, 極限技術部, 部長
MINOSHIMA Kohji Department of Mechanical Engineering, Kyoto University, Associate Professor, 工学部, 助教授 (50174107)
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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 |
¥10,800,000 (Direct Cost: ¥10,800,000)
Fiscal Year 1991: ¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1990: ¥8,900,000 (Direct Cost: ¥8,900,000)
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| Keywords | Scanning Tunneling / Atomic Force Microscope / In Situ Observation / Corrosion / Pitting Corrosion / Stress Corrosion Cracking / Intergranular Dissolution / Stainless Steel / 鋭敏化処理 |
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| Research Abstract |
A scanning tunneling microscope (STM) operating in a corrosive solution has been developed. The system consists of the STM operating in air and the one in a solution. The electrochemical cell is of a four-electrode type (bi-potentiostatic type), thereby the current associated with electrochemical reaction can be minimized : the potential of the tunneling tip is controlled so that the electrochemical current is reduced to the order of one-hundredth of the tunneling current. By using this bi-potentiostatic technique, the STM imaging can be achieved with the controlled potential of a sample. The other technique for minimizing the electrochemical current is a glass-coating Pt-Ir tunneling tip. Further, the system has a small, three-point bending type testing machine, thereby the imaging under an applied load can be done. By using this system, in situ observation of initiation and growth of micro-pitting on a stainless steel sample immersed in a 3.5% NaCl solution could be done. The imaging demonstrated that the in situ observation with the developed STM system can be operated under the conditions useful for investigating the mechanisms of corrosion damage including stress corrosion cracking, intergranular dissolution and pitting corrosion.
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