| Autor: |
R.F. Krause, R.J. Arsenault, J.C. Romero |
| Rok vydání: |
1995 |
| Předmět: |
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| Zdroj: |
Materials Science and Engineering: A. 201:13-23 |
| ISSN: |
0921-5093 |
| DOI: |
10.1016/0921-5093(94)09746-1 |
| Popis: |
The creep properties of an SiC/Al2O3 composite were studied under constant-load, four-point flexure tests. The initial stresses ranged from 50 to 350 MPa at temperatures in the range 1000–1300 °C in an air atmosphere. The final strain was as high as 3% at the highest test temperature. A subsequent transmission electron microscopy (TEM) investigation revealed no dislocation generation in the matrix; the few dislocations present were no different than those in the as-made samples. A certain amount of cavitation was observed on the tension face of the specimens tested at 1300 °C. The cavitation was seen to be generated at triple junctions in the matrix and along the whisker/matrix interface. Such cavities then grew into the cracks and, under load, propagated in a mixed mode across the sample. Unaccommodated grain boundary sliding was seen to generate voids along the grain boundaries which then joined into a microcrack and lowered the load-bearing capacity of the composite; this caused a marked drop in the strain to failure of the composite compared with the unreinforced matrix. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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