| Project/Area Number |
10650075
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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 |
Materials/Mechanics of materials
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| Research Institution | Yokohama National University |
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Principal Investigator |
ANDO Kotoji Yokohama National University, Faculty of Engineering, Professor, 工学部, 教授 (40017992)
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| Co-Investigator(Kenkyū-buntansha) |
CHU Min-cheol Yokohama National University, Faculty of Engineering, Professor, 工学部, 講師 (80293174)
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| Project Period (FY) |
1998 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 1999: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1998: ¥3,100,000 (Direct Cost: ¥3,100,000)
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| Keywords | SiィイD23ィエD2NィイD24ィエD2 / Crack-healing / Fatigue strength / SiC / YィイD22ィエD2SiィイD22ィエD2OィイD27ィエD2 / SiOィイD22ィエD2 / High temperature strength / Healing condition / 窒化ケイ素 / き裂治癒 / 化学成分 / イットリア / クリープ強度 / 治癒条件 / 窒化珪素 / き裂寸法 / き裂治癒条件 / き裂治癒物質 / 強度回復 |
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| Research Abstract |
Effect of Chemical Compositions, Atmosphers, Healing Time and Temperature on Healable Crack Size, Fatigue Strength of Healed Zone and High Temperature Strength of Healed Zone have been studied systematically. The silicon nitride which has excellent crack-healing ability was developed by this research.
The main conclutions are followings :
(1) The silicon nitride which used Y2O3 and Al2O3 as a sintering. additive have excellent crack healing ability. Especially, SiC is very useful to improve healing ability. (2) Crack healing ability in vacuum, argon, nitrogen and air, the materials can heal a crack in only air. (3) The silicon nitride of Si3N4/Y2O3/SiC has the best healing ability and the material could heal the quite large crack at from 800℃ to 1400℃, and strength recovered completely. (4) The materials (Si3N4/SiC/Y2O3/Al2O3 and Si3N4/SiC/Y2O3) healed the crack completely and most specimens fracture at base metal. (5) High temperature strength of crack healed zone is very sensitive to chemical compositions. (6) The crack healed zone of the materials (Si3N4/SiC/Y2O3/Al2O3) has enough strength up to 1000℃. (7) The crack healed zone of the materials (Si3N4/SiC/Y2O3) has excellent strength up to 1400℃
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