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High-temperature deformation and microstructural analysis for silicon nitride-scandium(III) oxideIt was indicated that Si3N4 doped with Sc2O3 may exhibit high temperature mechanical properties superior to Si3N4 systems with various other oxide sintered additives. High temperature deformation of samples was studied by characterizing the microstructures before and after deformation. It was found that elements of the additive, such as Sc and O, exist in small amounts at very thin grain boundary layers and most of them stay in secondary phases at tripple and multiple grain boundary junctions. These secondary phases are devitrified as crystalline Sc2Si2O7. Deformation of the samples was dominated by cavitational processes rather than movements of dislocations. Thus the excellent deformation resistance of the samples at high temperature can be attributed to the very small thickness of the grain boundary layers and the crystalline secondary phase.
Document ID
19930036471
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Cheong, Deock-Soo
(NASA Lewis Research Center Cleveland, OH, United States)
Sanders, William A.
(NASA Lewis Research Center Cleveland, OH, United States)
Date Acquired
August 15, 2013
Publication Date
December 1, 1992
Publication Information
Publication: American Ceramic Society, Journal
Volume: 75
Issue: 12
ISSN: 0002-7820
Subject Category
Nonmetallic Materials
Accession Number
93A20468
Distribution Limits
Public
Copyright
Other

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