| Project/Area Number |
07555209
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 試験 |
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| Research Field |
Structural/Functional materials
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| Research Institution | TOHOKU UNIVERSITY |
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Principal Investigator |
OKADA Masuo Faculty of Engineering, TOHOKU UNIVERSITY,Professor, 工学部, 教授 (80133049)
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| Co-Investigator(Kenkyū-buntansha) |
MATSUMURA Yuichi Yuasa Corp, Central Research Instit., Researcher, 研究員
TAKESHIMA Kenji Yuasa Corp, Central Research Instit., ManageroflSt LAB, 第1研究部長
TAKAMURA Hitoshi Faculty of Engineering, TOHOKU UNIVERSITY,Research Associate, 工学部, 助手 (30250715)
NAKAMURA Hajime Faculty of Engineering, TOHOKU UNIVERSITY,Research Associate, 工学部, 助手 (40250716)
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| Project Period (FY) |
1995 – 1996
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| Project Status |
Completed (Fiscal Year 1996)
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| Budget Amount *help |
¥12,800,000 (Direct Cost: ¥12,800,000)
Fiscal Year 1996: ¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1995: ¥10,800,000 (Direct Cost: ¥10,800,000)
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| Keywords | HYDROGEN ABLORBING ALLOYS / AMORPHOUS PHASE / La-Ni-B ALLOYS SYSTEM / MELT-QUENCHING / LaNi5 PHASE / FINE GRAIN SEIZE / Ni-HYDRIDES BATTERIES / PREVENTION ON PULVERIZING OF ALLOYS / 微粒化抑制 / アモルファス相 |
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| Research Abstract |
The purpose of the present studies is to obtain amorphous or nano-crystallized LaNi_5 phases for prolonging the life time of presently used Ni-hydrides batteries.
(1) Development alloys with microstructures consisted of LaNi_5 phases embedded in amorphous phases :
The present study successfully prepares the amorphous phase in large compositional range of La-Ni-B systems by melt-spinning. The temperature that LaNi_5 phase is formed is about 500ﾟC in the composition of (LaNi_5)_<0.8-0.7> (LaNi_<12>B_6)_<0.2-0.3>. The PCT measurements reveal that the amount of absorbed hydorgen in amorphous phase is small, that of crystallized alloys after heat-treatment increases and is around 0.9mass%.
(2) Amorphous-formation on La-Ni-B alloys with low B content and its hydrogen absorbing properties :
The formation of amorphous phase in the alloys with low B content is studied for the compositional alloys of LaNi_3B_<0.5>M_<0.5>(20at%La-10at%B), LaNi_<3.25>B_<0.25>M_<0.5>(20at%La-5at%B), LaNi_<4.85>B_<0.3>M_<0.5>(15at%La-4.5at%B). Then only LaNi_3B_<0.5>M_<0.5> alloy forms the amorphous phase, which absorbs the hydrogen of 0.6mass%. The rest of alloys such as LaNi_<3.25>B_<0.25>M_<0.5> consists of nearly LaNi_5 single phase, which becomes amorphous phase after absorbing hydrogen. But, LaN_<14.85>B_<0.3>M_<0.5> alloys absorb the hydrogen of around 1 mass% at 2MPa hydrogen pressure for all additional elements. After 30 hydride-dehydride cycle test, these crystallized alloys shows almost no degradation in comparison with LaNi_5 alloys, specially the alloy with Fe addition shows the prevention of pulverization of alloys.
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