Fabrication, phase transformation studies and characterization of SiC-AlN-Al/sub 2/OC ceramics: Progress report, February 1, 1988--October 31, 1988

Technical Report · Fri Jan 01 04:00:00 EST 1988

OSTI ID:6946528

Virkar, A V

Work has progressed in three principal areas. These are: (1) Phase equilibria and transformation in AlN-Al/sub 2/OC pseudobinary system. Major effort was devoted in this area. (2) Creep of polycrystalline AlN. The stress and the grain size dependence of creep rate in polycrystalline AlN has been examined. It has been shown that creep is diffusion controlled. Electron microscopic examination of the samples subjected to creep deformation has shown that voids are nucleated at the grain boundaries and these tend to link up under continued loading. A manuscript based on this work is currently under preparation. (3) Microstructural development in SiC-AlN and its effect on creep behavior. The modulations have been observed to occur in two directions unlike in AlN-Al/sub 2/OC in which the modulations occur only in one direction, namely (001). It has been observed that after long term annealing, the spinodally decomposed microstructure coarsens without causing grain growth. The creep rate of spinodally decomposed SiC-AlN is lower than the corresponding solid solution. A brief summary of the work done to date is given in the following. 2 figs.

• Research Organization: Utah Univ., Salt Lake City (USA). Dept. of Materials Science and Engineering
• DOE Contract Number: FG02-87ER45286
• OSTI ID: 6946528
• Report Number(s): DOE/ER/45286-2; ON: DE89003081
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201 -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
ALUMINIUM CARBIDES
ALUMINIUM COMPOUNDS
ALUMINIUM NITRIDES
ALUMINIUM OXIDES
CARBIDES
CARBON COMPOUNDS
CERAMICS
CHALCOGENIDES
CREEP
CRYSTAL STRUCTURE
DOCUMENT TYPES
FABRICATION
GRAIN SIZE
HOT PRESSING
MATERIALS WORKING
MECHANICAL PROPERTIES
MICROSTRUCTURE
NITRIDES
NITROGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
PNICTIDES
PRESSING
PROGRESS REPORT
SILICON CARBIDES
SILICON COMPOUNDS
SIZE