Static and Cyclic Fatigue of Alumina at High Temperatures: II, Failure Analysis |
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Authors: | Chih-Kuang Jack Lin Darrell F. Socie Youren Xu Avigdor Zangvil |
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Affiliation: | Department of Mechanical and Industrial Engineering and Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 |
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Abstract: | Failure mechanisms of an alumina, tested at 1200°C under static and various cyclic loading conditions, were examined. Slow crack growth of a single crack is the dominant mechanism for the failure in specimens under cyclic loading with a short duration of maximum stress at all applied stress levels, as well as at high applied loads for static loading and cyclic loading with a longer hold time at maximum stress. At low stress levels, failure of static loading and cyclic loading with a longer hold time at maximum stress might occur by formation and/or growth of multiple macrocracks. More importantly, for all the given loading conditions. The viscous glassy phase behind the crack tip could have a bridging effect on the crack surfaces. A simplified model for calculating effective stress intensity factor at the crack tip under static and various cyclic loading demonstrated a trend consistent with the stress–life data. |
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Keywords: | alumina fatigue high temperature crack growth glass |
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