Residual [alpha]-Si[sub 3]N[sub 4] in O[prime] crystals in CeO[sub 2]-doped O[prime] + [beta][prime] SiAlON ceramics

Journal Article · Mon Aug 01 04:00:00 EDT 1994 · Journal of the American Ceramic Society; (United States)

DOI:https://doi.org/10.1111/j.1151-2916.1994.tb07123.x· OSTI ID:6988672

Xu, Y; Huang, C M; Kriven, W M; Zangvil, A ^[1]

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1. Univ. of Illinois, Urbana, IL (United States)

The microstructure of a pressureless sintered (1,605 C, 90 min) O[prime] + [beta][prime] SiAlON ceramic with CeO[sub 2] doping has been investigated. It is duplex in nature, consisting of very large, slablike elongated O[prime] grains (20--30 [mu]m long), and a continuous matrix of small rodlike [beta][prime] grains (< 1.0 [mu]m in length). Many [alpha]-Si[sub 3]N[sub 4] inclusions (0.1--0.5 [mu]m in size) were found in the large O[prime] grains. CeO[sub 2]-doping and its high doping level as well as the high Al[sub 2]O[sub 3] concentration were thought to be the main reasons for accelerating the reaction between the [alpha]-Si[sub 3]N[sub 4] and the Si-Al-O-N liquid to precipitate O[prime]-SiAlON. This caused the supergrowth of O[prime] grains. The rapid growth of O[prime] crystals isolated the remnant [alpha]-Si[sub 3]N[sub 4] from the reacting liquid, resulting in a delay in the [alpha] [yields] [beta]-Si[sub 3]N[sub 4] transformation. The large O[prime] grains and the [alpha]-Si[sub 3]N[sub 4] inclusions have a pronounced effect on the strength degradation of O[prime] + [beta][prime] ceramics.

• DOE Contract Number: FG02-91ER45439
• OSTI ID: 6988672
• Journal Information: Journal of the American Ceramic Society; (United States), Journal Name: Journal of the American Ceramic Society; (United States) Vol. 77:8; ISSN 0002-7820; ISSN JACTAW
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202* -- Ceramics
Cermets
&amp; Refractories-- Structure &amp; Phase Studies
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CERIUM COMPOUNDS
CERIUM OXIDES
CHALCOGENIDES
DATA
DOPED MATERIALS
EXPERIMENTAL DATA
GRAIN SIZE
INFORMATION
MATERIALS
MICROSTRUCTURE
NITRIDES
NITROGEN COMPOUNDS
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
PNICTIDES
RARE EARTH COMPOUNDS
SILICON COMPOUNDS
SILICON NITRIDES
SIZE