| Project/Area Number |
16360361
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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 | Tokyo Institute of Technology |
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Principal Investigator |
MARUYAMA Toshio Tokyo Institute of Technology, Department of Metallurgy and Ceramic Materials, Professor, 大学院理工学研究科, 教授 (20114895)
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| Co-Investigator(Kenkyū-buntansha) |
KAWAMURA Kenichi Tokyo Institute of Technology, Department of Metallurgy and Ceramic Materials, Associate Professor, 大学院理工学研究科, 助教授 (50270830)
UEDA Mitsutoshi Tokyo Institute of Technology, Department of Metallurgy and Ceramic Materials, Assistant Professor, 大学院理工学研究科, 助手 (90376939)
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| Project Period (FY) |
2004 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥14,100,000 (Direct Cost: ¥14,100,000)
Fiscal Year 2006: ¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2005: ¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2004: ¥6,700,000 (Direct Cost: ¥6,700,000)
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| Keywords | Highly efficient energy conversion / Lattice difect / Structural / functional materials / Material treatment and processing / Energy saving / Solid oxide fuel cell / 高温酸化皮膜 / 化学ポテンシャル分析 / イオン流束の発散 / ボイド形成 / Cr2O3皮膜 / Fe3O4皮膜 / 有効拡散係数 / 過熱器管 / 鉄-クロム合金 / 水蒸気酸化 / マグネタイト / 化学ポテンシャル分布 / 流速と発散 |
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| Research Abstract |
(1)Quantitative prediction of void formation in a growing scales in high temperature oxidation
Equations have been proposed for evaluation of chemical potential distribution, ionic fluxes and its divergence in a growing oxide scales. The divergence was proved to be the good measure for evaluating the void formation. The validity was experimentally confirmed in magnetite scales formed in high temperature oxidation of iron.
(2)High temperature oxidation of ferritiv Fe-Cr alloys for interconnects in solid oxide fuel cell (SOFC) and electrical conductivity of the oxide scale.
Simulating the operation condition of SOFC, high temperature oxidation of Fe-16Cr alloys was conducted in the dual atmosphere, in which specimens were exposed air for the cathode and the mixture of H2O (97%) and H2 (3%) at 1073 K. The continuous protective Cr2O3 scales were formed on both sides. The growth rates were quite similar, indicating the major defect was interstitial ion of Cr in two cases.
The estimation of the
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oxygen potential distribution clarified that the oxygen potential is low almost the whole region in scales. This fact predicted the reason why the electrical conductivity of the Cr2O3 scales were high. Applied external currents retarded the growth rate of Cr203 on the cathode and enhanced it on the anode. The equations were proposed for evaluating the scale growth rate under the external current and the equations predicted the growth rate in the long term exposures.
(3)Control of microstructure development and design of the function of the scales.
The summary of this project is the following
(1)The quantitative prediction of microstructure development is possible with diffusion coefficients of constituent ions as a function of oxygen potential.
(2)For controlling microstructure, it is dispensable to design the diffusivity. The appropriate doping is an possibility for the design of the microstructure.
(3)The evaluation of chemical potential distribution and divergences of ionic fluxes is very powerful for controlling microstructures and designing the function of scales. Less
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