| Project/Area Number |
17560624
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Structural/Functional materials
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| Research Institution | Oita National College of Technology |
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Principal Investigator |
MATSUMOTO Yoshihisa Oita National College of Technology, Department of Mechanical Engineering, Associate Professor, 機械工学科, 助教授 (40219522)
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| Co-Investigator(Kenkyū-buntansha) |
NAMBU Tomonori Suzuka National College of Technology, Department of Materials Science and Engineering, Assistant Professor, 材料工学科, 講師 (10270274)
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| Project Period (FY) |
2005 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 2006: ¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 2005: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | Hydrogen / Metallic physical properties / Fuel cell / Materials processing and treatment / Hydrogen permeable membrane / Hydrogen embrittlement / Small punch test / Niobium / 水素脆化 |
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| Research Abstract |
This research aims at (1) establishment of the hydrogen embrittlement in-situ measuring method of the metallic hydrogen permeable membranes, (2) elucidation of the effects of dissolved hydrogen on the mechanical properties and (3) suggestion some guidelines of a new metallic membrane design which can be sustainable hydrogen pressure difference. The results are as follows.
1. By using a newly developed in-situ small punch apparatus, the mechanism of hydrogen embrittlement of pure niobium metal membrane was investigated under hydrogen permeation.
2. The coverage for the ductile-brittle transition of the palladium-coated niobium membrane was determined by a series of the in-situ small punch test and the PCT measurements (Sievert's method). Compared with the one proposed by previous reports, the measured boundary showed great shift to the lower hydrogen content region.
3. The membrane was deformed and fractured easily when about 10% lattice contraction was introduced to it by lowering the hydrogen pressure at 673K, at which the dehydrogenation reaction progressed smoothly.
4. Although, under the practical hydrogen pressure conditions, pure niobium dissolves a great amount of hydrogen and causes remarkable embrittlement, the reduction of dissolving hydrogen concentration can control the proof hydrogen embrittlement.
5. An alloy design planned so as to obtain high hydrogen concentration difference on both sides of the membrane can become a new niobium membrane provided with both hydrogen permeability and strong resistance against hydrogen embrittlement. For instance, when palladium was added to niobium, the amount of dissolved hydrogen decreased, and palladium addition contributed to giving the resistance to hydrogen embrittlement
6. The present results will provide us with a clue to the design of niobium-based permeable membrane against the hydrogen embrittlement.
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