1992 Fiscal Year Final Research Report Summary
Preparation and Properties of Thermoelectric Materials by PM Process.
| Project/Area Number |
03650554
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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 |
金属加工(含鋳造)
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| Research Institution | Osaka University |
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Principal Investigator |
NAGAI Hiroshi Osaka Univ. Mat.Sci.Eng.,Professor, 工学部, 教授 (80029206)
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| Co-Investigator(Kenkyū-buntansha) |
YOKOTA Masaru Takaoka Junior College, Professor, 金属工芸科, 教授 (10029225)
KATSUYAMA Shigeru Osaka Univ. Mat.Sci.Eng. Assistant, 工学部, 助手 (00224478)
MAJIMA Kazuhiko Osaka Univ. Mat.Sci.Eng. Assistant, 工学部, 助手 (60029270)
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| Project Period (FY) |
1991 – 1992
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| Keywords | Thermoelectric / FeSi_2 / LaS_x / Powder Metallurgy / Rare Earth / Chalcogenide / Sintering / Thermoelectric Power |
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| Research Abstract |
In this study, the preparation process and the thermoelectric properties of beta-FeSi_2 and gamma-LaS_x were investigated. The results are summarized as follows:
1. Preparation and properties of beta-FeSi_2.
1.1. Effect of Mechanical Grinding(MG)
MG and Hot-pressing significantly improved the densification and transition from alpha+epsilon phase to beta-phase. Finely dispersed epsilon-phase in beta-FeSi_2 by MG increased the thermoelectric properties by decreasing the resistivity.
1.2. Effect of Co, Ni, B Addition.
Co, Ni addition markedly accelerated the sintering of FeSi_2, while B addition hindered the sintering. Co addition increased the thermoelectric power, while Ni and B addition decreased the thermoelectric power.
2. Preparation and properties of gamma-LaS_x.
Thre are three phases(alpha、beta、gamma) in LaS_x(4/3*X*3/2) and gamma-LaS_x phase is expected to be good thermoelectric material. However, the conditions to prepare gamma-LaS_x phase have not been clarified. In this study, the preparation process of gamma-LaS_x and their thermoelectric properties were investigated. Through solid phase reaction between metallic La and S ina quartz capsule at 1273 K, it became clear that gamma-phase was obtained in the low S compositions.
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