2019 Fiscal Year Final Research Report
Preparation of Novel Silicon Nitride Ceramics Using Non-oxide Sintering Agents and Their Applications for Structural/Functional Materials
| Project/Area Number |
16H04228
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Materials/Mechanics of materials
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| Research Institution | Tohoku University |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
山本 剛 東北大学, 工学研究科, 准教授 (30436159)
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| Project Period (FY) |
2016-04-01 – 2019-03-31
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| Keywords | 材料設計 / プロセス / 物性 / 評価 / セラミックス / 焼結 / 高温特性 / トライボロジー特性 |
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| Outline of Final Research Achievements |
The use of non-oxide sintering agents was investigated to prepare silicon nitride ceramics with enhanced high-temperature properties. A non-oxide sintering agent containing yttrium was selected and silicon nitride samples were successfully sintered with a full density utilizing the agent. Three-point bending tests conducted at argon gas environment revealed that the silicon nitride prepared with the non-oxide sintering agent maintained higher flexural strength at high temperatures compared with that for an oxide sintering agent, yttria. The phases of the non-oxide, and oxide sintering agents in the sintered condition were shown to be crystal and amorphous, respectively. The crystal phase may be a plausible reason for the improved high-temperature strength in the non-oxide sintering. Furthermore, the addition of the non-oxide agent caused no deterioration in the thermal conductivity measured with a laser flash method, and led to excellent tribological characteristics in water.
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| Free Research Field |
材料強度学
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| Academic Significance and Societal Importance of the Research Achievements |
窒化ケイ素において非酸化物焼結助剤を利用することで緻密な焼結体が得られること，ならびに高温強度特性が向上することを示したことは，世界で初めての試みであり，かつセラミックス科学の分野で重要な学術的知見を提供するものである．従来の窒化ケイ素焼結で用いられてきた酸化物焼結助剤では，高温領域で強度が著しく低下していた．本研究の成果は，この課題を克服するルートを提供するもので，高温セラミックス構造材料ならびに高温パワー半導体材料等への適用を大きく前進させるものである．また，開発された窒化ケイ素は良好な摩擦特性が得られていることから，高温摺動材料への応用が期待される．
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