| Project/Area Number |
06650081
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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 |
Materials/Mechanics of materials
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| Research Institution | IWATE UNIVERSITY |
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Principal Investigator |
KATAGIRI Kazumune IWATE UNIV., Faculty of Eng., Professor, 工学部, 教授 (90029893)
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| Co-Investigator(Kenkyū-buntansha) |
KASABA Koichi IWATE UNIV., Faculty of Eng., Assist.Prof., 工学部, 助手 (00271841)
SHIN Hyung-seop IWATE UNIV., Faculty of Eng., Lecture, 工学部, 講師 (20240658)
SATO Tadashi IWATE UNIV., Faculty of Eng., Assoc., Prof., 工学部, 助教授 (30003859)
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1995: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1994: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | Fatigue Strength / Fatigue Crack Propagation / Variable Stressing / Elevated Temperature / Metal Matrix Composites / Die Casting / NiAl Particle / Ni_3Al Particle / アルミニウム合金 / 体積分率 / 空洞 / 析出物 |
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| Research Abstract |
Through the evaluation on static mechanical properties and fatigue characteristics as well as the microscopiic observations, it has been revealed that the intermetalic compund, NiAl and Ni_3Al, particle-reinforced Al die cast are superior to the SiC reinforced one as is shown in the followings.
1. The endurance limit increases by reinforcement at room temperature. While the endurance limit ofmatrix die cast and SiC particle reinforced one decrease with temperature rise, reinforcement is effective at 200ﾟC in the NiAl and up to 300ﾟC in Ni_3Al particle. The endurance limit and fatigue life-time increase with increase in the particle volume fraction in all temperature ranges examined. Although these characteristics basically corresponds to that of 0.2% proof stress, suppression of local slip by the intermetalic compound particles together with precipitates such as Al_3Ni significantly contribute the fatigue strength at low stress.
2. Fatigue crack initiates at voids located near the surfac
… More
e which are introduced on casting in all die casts. Crack propagates through the matrix and along the particle-matrix interface, and the former is dominant at elevated temperatures. No cracking in Ni_3Al particle is found.
3. Fatigue crack propagation resistance of 2.5 vol% NiAl particle reinforced die cast is higher at near threshold region than the matrix and SiC reinforced one. It decreases when the particle volumefraction increase beyond 2.5%. In the crack propagation rate range of Paris rule or beyond it, 2.5 vol% NiAl particle reinforced die cast has higher crack propagation resistance while SiC has such low resistance as that in the matrix : These characteristics dose not coinside with that of fracture toughness.
4. NiAl particle reinforce die cast has excellent fatigue characteristics against the two stage (low-high and high low) varying stress fatigue. Acceleration of fatigue crack propagation under intermittent oversrtressing and its microscopic mechanism in the intermetalic compound particle reinforced die cast is open problem. Less
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