2005 Fiscal Year Final Research Report Summary
Search for pulverizing materials by hydrogen gas
| Project/Area Number |
15560636
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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 |
Material processing/treatments
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| Research Institution | National Institute for Materials Science |
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Principal Investigator |
OKUYAMA Hideo National Institute for Materials Science, Materials Engineering Laboratory, Senior Researcher, 材料研究所, 主幹エンジニア (80354215)
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| Co-Investigator(Kenkyū-buntansha) |
SAKKA Yoshio National Institute for Materials Science, Materials Engineering Laboratory, Director, 材料研究所, ディレクター (00354217)
SUZUKI Tohru National Institute for Materials Science, Materials Engineering Laboratory, Senior Researcher, 材料研究所, 主幹研究員 (50267407)
UCHIKOSHI Tetsuo National Institute for Materials Science, Materials Engineering Laboratory, Senior Researcher, 材料研究所, 主幹研究員 (90354216)
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| Project Period (FY) |
2003 – 2005
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| Keywords | Hydrogen / Pulverization / Energy saving / Hydrogen storage / Nb alloys / Nd alloys |
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| Research Abstract |
During our studies on the hydrogenation of metals, we found interesting phenomena ; some kinds of alloys adsorb a lot of hydrogen at room temperature and atmospheric pressure, and pulverized. In order to develop a new, energy-saving powder manufacturing process, the pulverization phenomena of Nb-Zr-Fe, Nd-Ni and Nd-Fe alloy systems due to hydrogenation were studied. The hydrogenation was performed under the hydrogen atmosphere of 0.1MPa at room temperature in an arc melting chamber without exposure to air after arc-melting of the alloys.
The pulverization was dependent on the alloy component. The compositions of Nb-Zr-Fe alloys for easy pulverization were in the range of 15-30 at%Fe with Nb/Zr ≒1/1. The pulverized powder had flakey shapes with many fine cracks and wide-ranging size distribution between 5 and 200 μm. The concentration of hydrogen in the powder was as high as 1.8 mass%. The hydrogen evolved from the powder by heating at the temperatures from 473K to 773K.
In case of Nd-Ni alloys, four kinds of samples with 10, 20, 40 and 60 at%Ni were tested. All of them showed the pulverization phenomena, which were promoted by a preliminary arc-melting in Ar-40vol%H2 gas for 4〜5 s. The concentration of hydrogen in the powder was also 1.8 mass%. Nd alloys with 9, 20, 52, 72 at%Fe also showed the pulverization phenomenon, but Nd-90 at%Fe alloy was not pulverized probably due to the less adsorption of hydrogen. The pulverization of Nd-based alloys was slower than that of Nb-based alloys. This difference is related to the cleanliness of the surfaces and the easiness of oxidization.
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