Development of advanced fiber reinforced ceramics: Final report

Technical Report · Thu Jan 01 04:00:00 EST 1987

OSTI ID:6093393

Starr, T L; Harris, J N

A fundamental problem in the processing of ceramic composites is the fact that the incorporated fibers tend to reinforce the ''green'' structure, preventing the volume reduction and densification that usually is obtained during free sintering. Hot pressing is one approach to overcoming this problem, providing the necessary densification by application of pressure. An alternative approach is to maximize the green density of composite preforms and to utilize volume filling techniques to achieve high density. This type of process is more suitable for fabrication of large and complex shapes. Development of such processing is the primary thrust of this research program. The results of this program are organized into four topics. A review of models for the physical properties of composites is given. New understanding of cast and sinter processing of fiber/powder blends was gained and used to produce consistent, dense composites. These results are broadly applicable to many composite systems. Development work on silica and silicon nitride matrix composites is reported. The silica composites were fabricated using a precursor resin infiltration process to increase the sintered density. Silicon nitride composites were processed using reaction sintering of silicon powder/fiber preforms. In both cases, composites were produced with densities comparable to monolithic materials and using fabrication techniques suitable for large, complex components. This emphasis on ''scale-able'' processing is an important theme running throughout this work. 17 refs., 46 figs., 14 tabs.

• Research Organization: Georgia Inst. of Tech., Atlanta (USA). Research Inst.
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 6093393
• Report Number(s): ORNL/Sub-83-43369/01; ON: DE88000779
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360601* -- Other Materials-- Preparation & Manufacture
360603 -- Materials-- Properties
CARBIDES
CARBON COMPOUNDS
CASTING
CERAMICS
CHALCOGENIDES
CHEMICAL REACTIONS
COMPOSITE MATERIALS
CORRELATIONS
CRACK PROPAGATION
CRYSTALS
ELECTRON MICROSCOPY
FABRICATION
FLEXURAL STRENGTH
FRACTURE PROPERTIES
MATERIALS
MATERIALS WORKING
MECHANICAL PROPERTIES
MICROSCOPY
MINERALS
MONOCRYSTALS
NITRIDATION
NITRIDES
NITROGEN COMPOUNDS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PNICTIDES
POROSITY
PRESSING
REINFORCED MATERIALS
SCANNING ELECTRON MICROSCOPY
SILICA
SILICON CARBIDES
SILICON COMPOUNDS
SILICON NITRIDES
SILICON OXIDES
SINTERING
WHISKERS
YOUNG MODULUS