Abstract
The dynamic fatigue performance of an injection molded, hot-isostatically pressed silicon nitride containing 6 wt.% yttrium oxide as a sintering aid was examined at 1000, 1200, and 1400 °C, in four-point flexure in ambient air and argon. This material was more susceptible to slow crack growth, as reflected by the slopes of the flexure strength vs. stressing rate curves, as the test temperature was increased in both environments. At the same temperature, this material was much more susceptible to slow crack growth in ambient air than in argon. Stress-corrosion cracking (and not creep damage) was the dominant damage mechanism, although the material crept at the slower stressing rates in both environments. Stress-corrosion cracking ultimately caused a reduction in strength.
Original language | English |
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Pages (from-to) | 257-266 |
Number of pages | 10 |
Journal | Materials Science and Engineering: A |
Volume | 191 |
Issue number | 1-2 |
DOIs | |
State | Published - Feb 1 1995 |
Externally published | Yes |
Funding
The authors wish to thank Drs. S.D. Nunn and P.F. Tortorelli for reviewing the manuscript and for their helpful comments. Research was sponsored by the US Department of Energy, Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Transportation Technologies, as part of the High Temperature Materials Laboratory User Program, under contract DE-AC05840R21400 with Martin Marietta Energy Systems, Inc. Research at Allison Engine Company was sponsored by the US Department of Energy, Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Transportation Technologies, as part of the Ceramic Technology Project of the Materials Development Program, under contract DE-AC05840R21400 with Martin Marietta Energy Systems, Inc.
Keywords
- Fatigue
- Hot isostatic pressing
- Nitrogen
- Silicon