Fibrous monolithic ceramics; 3: Mechanical properties and oxidation behavior of silicon carbide/boron nitride system
- Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Materials Science and Engineering
Fibrous monolithic ceramics were fabricated in the SiC/BN system. The microstructure consists of high-aspect-ratio polycrystalline cells of SiC separated by cell boundaries of BN. The fibrous monolith with aligned cells fails non-catastrophically in flexure, with delamination cracking along the BN cell boundaries. Indentations cause controlled damage on the surface, but no strength-degrading flaws. The flexural strength is in the range 300--375 MPa, and the estimated shear strength is [approximately]14 MPa. The SiC/BN fibrous monoliths also show excellent resistance to high-temperature oxidation in air. Noncatastrophic fracture behavior is observed at room temperature after heat treatments between 1,200 and 1,500 C. The SiC cells on the surface are oxidized to form a protective silicate scale, which prevents deterioration of the BN cell boundaries.
- OSTI ID:
- 7045138
- Journal Information:
- Journal of the American Ceramic Society; (United States), Journal Name: Journal of the American Ceramic Society; (United States) Vol. 77:5; ISSN 0002-7820; ISSN JACTAW
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360602* -- Other Materials-- Structure & Phase Studies
360603 -- Materials-- Properties
360604 -- Materials-- Corrosion
Erosion
& Degradation
BORON COMPOUNDS
BORON NITRIDES
CARBIDES
CARBON COMPOUNDS
CHEMICAL REACTIONS
COMPOSITE MATERIALS
DATA
EXPERIMENTAL DATA
FIBERS
FRACTURE PROPERTIES
INFORMATION
MATERIALS
MECHANICAL PROPERTIES
MICROSTRUCTURE
NITRIDES
NITROGEN COMPOUNDS
NUMERICAL DATA
OXIDATION
PNICTIDES
SILICON CARBIDES
SILICON COMPOUNDS