| Project/Area Number |
60550517
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
金属材料(含表面処理・腐食防食)
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| Research Institution | NAGASAKI UNIVERSITY |
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Principal Investigator |
SAKAMOTO Yoshiichi Nagasaki University, Faculty of Engineering, Professor, 工学部, 教授 (50026019)
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| Co-Investigator(Kenkyū-buntansha) |
BABA Koumiei Nagasaki University, Faculty of Engineering, Research assistant, 工学部, 助手 (40156534)
HASAKA Masayuki Nagasaki University, Faculty of Engineering, Assistant professor, 工学部, 助教授 (30039698)
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| Project Period (FY) |
1985 – 1987
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| Project Status |
Completed (Fiscal Year 1987)
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| Budget Amount *help |
¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1987: ¥100,000 (Direct Cost: ¥100,000)
Fiscal Year 1986: ¥700,000 (Direct Cost: ¥700,000)
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| Keywords | Thermodynamic parameters of hydrogen in metals / Pd-B / Pd--Y / Pd-Ni / Pd-V alloys / Partial molar enthalpy <DELTA>H^^<.o( / )H> of hydrogen solution at infinite dilution and its entropy <DELTA>S^^<.o( / )H> / Thermodynamic parameters of <beta>-hydride formation / Pd-B合金 / 水素の無限希薄溶体における相体部分モルエンタルピーおよびエントロピー / 水素化物の標準生成エンタルピー変化およびエントロピー変化 |
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| Research Abstract |
The hydrogen absorption characteristics of Pd binary allosy (alloying elements = B, Y, Ni and V) have been investigated by means of pressure-composition isotherms. The relative partial molar enthalpy <DELTA>H^o_ of solution of hydrogen at infinite dilution in the "expanded" palladium alloys such as Pd-B and Pd-Y becomes more exothermic with increasing the solute contents, whereas for the "contracted" alloys such as Pd-Ni and Pd-V, values of <DELTA>H^o_ are less exothermic than for palladuim. The results are discussed in terms of the lattice dilation effect. The behaviour of the partial molar entropy of hydrogen at infinite dilution <DELTA>^So_H in the alloys can be explained by assuming the occupation of only interstices surrounded by palladium atom nearest neighbours: (<DELTA>S^o_)_<alloy>=(<DELTA>S^o_)_<Pd> + R1n(1-X_u)^z, where R is the gas constant X_u the solute atom fraction, z the number of lattice sites that are the first and/or second nearest neighbors to an octahedral interstitial site. The effect of the alloying elements on the apparnt H-H attractive interaction associated with the excess chemical potential at small concentration was discussed. The thermodynamic parameters of <beta>-hydride formation were obtained by the <alpha>/<beta> plateau pressure measurements. Furthermore, the solvus thermodynamic quantities were determined from the solvus composition for the alloys.
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