Micromechanisms of toughening in a particulate reinforced ceramic matrix composite
The fracture toughness of sintered silicon carbide and silicon carbide reinforced with particulate titanium diboride is evaluated using chevron-notched testpieces in bending, at ambient temperature, 1200 C in air and 1200 and 1600 C in vacuum. There is a significant increase in toughness observed for the composite material at ambient temperature, but no significant increase in toughness above that of the monolithic material is measured both at 1200 and 1600 C. The predominant toughening mechanism in the composite material is therefore deduced to derive from a favorable distribution of thermal residual stresses, although detailed surface-roughness analysis indicates that increased crack deflection occurs at room temperature only. Metallographic observations and fractographic observations (of matched specimen halves) suggest probable mechanisms of crack extension on a microstructural scale. 11 refs.
- OSTI ID:
- 7040043
- Report Number(s):
- CONF-920144-; CODEN: CESPD
- Journal Information:
- Ceramic Engineering and Science Proceedings; (United States), Vol. 13:7-8; Conference: 16. annual conference on composites, materials, and structures, Cocoa Beach, FL (United States), 13-16 Jan 1992; ISSN 0196-6219
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
COMPOSITE MATERIALS
FRACTURE PROPERTIES
SILICON CARBIDES
TITANIUM BORIDES
BENDING
CRACK PROPAGATION
DISTRIBUTION
FRACTOGRAPHY
METALLOGRAPHY
MICROSTRUCTURE
PARTICULATES
REINFORCED MATERIALS
RESIDUAL STRESSES
ROUGHNESS
SILICON NITRIDES
SINTERING
TEMPERATURE RANGE 0273-0400 K
TEMPERATURE RANGE 1000-4000 K
THERMAL STRESSES
BORIDES
BORON COMPOUNDS
CARBIDES
CARBON COMPOUNDS
CRYSTAL STRUCTURE
DEFORMATION
FABRICATION
MATERIALS
MECHANICAL PROPERTIES
NITRIDES
NITROGEN COMPOUNDS
PARTICLES
PNICTIDES
SILICON COMPOUNDS
STRESSES
SURFACE PROPERTIES
TEMPERATURE RANGE
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
360203* - Ceramics
Cermets
& Refractories- Mechanical Properties
360603 - Materials- Properties