Fabrication, phase transformation studies and characterization of SiC-AlN-Al sub 2 OC ceramics

Technical Report · Fri Jan 11 00:00:00 EST 1991

OSTI ID:5554507

Virkar, A N

The principal objective of the work has been to examine phase relations, phase transformations, the resulting precipitate morphologies and their influence on high temperature creep of the SiC-A1N-Al{sub 2}OC ceramics. This system was chosen as prior work has shown the existence of extensive of solid solubility at elevated temperatures and tendency for phase separation at lower temperatures. Phase separation by cellular precipitation as well as by the formation of modulated structures has been documented. The directions of modulations can be rationalized in terms of elastic strain energy considerations of the coherent precipitates. The shapes of the precipitates are also in accord with theoretical predictions. This report briefly describes the mechanisms of phase decomposition with particular emphasis on the role of elastic strain energy, the work on electron microscopic examination of modulated structures, and results of creep studies. 9 refs., 7 figs.

• Research Organization: Utah Univ., Salt Lake City, UT (USA). Dept. of Materials Science and Engineering
• Sponsoring Organization: USDOE; USDOE, Washington, DC (USA)
• DOE Contract Number: FG02-87ER45286
• OSTI ID: 5554507
• Report Number(s): DOE/ER/45286-4; ON: DE91013296
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM COMPOUNDS
CREEP
PHASE TRANSFORMATIONS
ALUMINIUM NITRIDES
SILICON CARBIDES
PHASE STUDIES
PROGRESS REPORT
SOLUBILITY
X-RAY DIFFRACTION
CARBIDES
CARBON COMPOUNDS
COHERENT SCATTERING
DIFFRACTION
DOCUMENT TYPES
MECHANICAL PROPERTIES
NITRIDES
NITROGEN COMPOUNDS
PNICTIDES
SCATTERING
SILICON COMPOUNDS
360203* - Ceramics
Cermets
& Refractories- Mechanical Properties
360202 - Ceramics
Cermets
& Refractories- Structure & Phase Studies
360201 - Ceramics
Cermets
& Refractories- Preparation & Fabrication