Sintered Al/sub 2/O/sub 3/-SiC-whisker composites
Pressureless sintering of Al/sub 2/O/sub 3/-SiC-whisker composites is a viable method of fabrication. Densification of pressed powder-whisker compacts is inhibited by the SiC whiskers because rearrangement of the whiskers during shrinkage is difficult. To promote sintering, a number of techniques were effective, such as lowering the whisker aspect ratio, adjusting the Al/sub 2/O/sub 3/ particle size to optimize green density and use of a liquid phase sintering aid (e.g., Y/sub 2/O/sub 3/ and MgO). At the present time, Al/sub 2/O/sub 3/-SiC-whisker composites with loadings less than or equal to10 vol% whiskers can be successfully sintered to greater than or equal to 95% of theoretical density and hot isostatically pressed without encapsulation to >98% of theoretical density. With whisker contents >10 vol%, densification is severely inhibited and sintered materials without closed porosity are obtained.
- Research Organization:
- Oak Ridge National Lab., Metals and Ceramics Div., Oak Ridge, TN 37831
- DOE Contract Number:
- AC05-84OR21400
- OSTI ID:
- 6375613
- Journal Information:
- Am. Ceram. Soc. Bull.; (United States), Journal Name: Am. Ceram. Soc. Bull.; (United States) Vol. 66:2; ISSN ACSBA
- Country of Publication:
- United States
- Language:
- English
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360202 -- Ceramics
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360600 -- Other Materials
ALKALINE EARTH METAL COMPOUNDS
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
ASPECT RATIO
CARBIDES
CARBON COMPOUNDS
CHALCOGENIDES
COMPACTING
COMPOSITE MATERIALS
CRYSTALS
DENSITY
FABRICATION
HOT PRESSING
MAGNESIUM COMPOUNDS
MAGNESIUM OXIDES
MATERIALS
MATERIALS WORKING
MONOCRYSTALS
OXIDES
OXYGEN COMPOUNDS
PARTICLE SIZE
PHYSICAL PROPERTIES
POROSITY
PRESSING
SILICON CARBIDES
SILICON COMPOUNDS
SINTERING
SIZE
TRANSITION ELEMENT COMPOUNDS
WHISKERS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES