Nucleation and growth of [beta][prime]-SiAlON

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

DOI:https://doi.org/10.1111/j.1151-2916.1994.tb07042.x· OSTI ID:7154820

Hwang, S L; Chen, I W ^[1]

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1. Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Materials Science and Engineering

Elongated [beta][prime]-SiAlON grains grown from several fine-grained Y[sub m/3]Si[sub 12[minus](m+n)]Al[sub m+n]O[sub n]N[sub 16[minus]n] compositions with [alpha]-Si[sub 3]N[sub 4], AlN, Al[sub 2]O[sub 3], and Y[sub 2]O[sub 3] starting materials have been examined. These grains have large aspect ratios and are oriented along the [0001] axis. TEM structural and chemical analysis suggests that they are nucleated from various seed crystals, which can be [alpha]-Si[sub 3]N[sub 4], [beta]-Si[sub 3]N[sub 4], or other [beta][prime]-SiAlON. The [beta][prime]-SiAlON seed and initial precipitation on [beta]-Si[sub 3]N[sub 4] show a higher content of Al and O, indicating that a large transient supersaturation of Al and O in the liquid is instrumental for [beta][prime]-SiAlON formation, whereas subsequent growth proceeds under a much lower driving force. The misfit between phases is accommodated by interfacial dislocations (c-type and a-type). Fully grown [beta][prime]-SiAlON grains usually contain several variants independently nucleated from the same seed. In particular, the two alternative [alpha]/[beta] phase-matching possibilities result in two [0001] growth habits separated by a twin boundary.

• OSTI ID: 7154820
• Journal Information: Journal of the American Ceramic Society; (United States), Journal Name: Journal of the American Ceramic Society; (United States) Vol. 77:7; ISSN 0002-7820; ISSN JACTAW
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
ALUMINIUM COMPOUNDS
ALUMINIUM NITRIDES
ALUMINIUM OXIDES
CHALCOGENIDES
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
DATA
EXPERIMENTAL DATA
GRAIN GROWTH
GRAIN ORIENTATION
INFORMATION
MICROSTRUCTURE
NITRIDES
NITROGEN COMPOUNDS
NUCLEATION
NUMERICAL DATA
ORIENTATION
OXIDES
OXYGEN COMPOUNDS
PNICTIDES
SILICON COMPOUNDS
SILICON NITRIDES
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES