Silicon nitride based ceramic nanocomposites

Journal Article · Fri Mar 01 04:00:00 EST 1996 · Journal of the American Ceramic Society

DOI:https://doi.org/10.1111/j.1151-2916.1996.tb07914.x· OSTI ID:230729

Pan, X; Mayer, J; Ruehle, M ^[1]; Niihara, Koichi ^[2]

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1. Max-Planck-Inst. fuer Metallforschung, Stuttgart (Germany). Inst. fuer Werkstoffwissenschaft
2. Osaka Univ. (Japan). Inst. of Scientific and Industrial Research

Nanocomposites (Si{sub 3}N{sub 4}/SiC) were studied by combined high-resolution transmission electron microscopy and electron energy-loss spectroscopic imaging (ESI) techniques. In ESI micrographs three types of crystalline grains were distinguished: Si{sub 3}N{sub 4} matrix grains ({approximately} 0.5 {micro}m), nanosized SiC particles (< 100 nm) embedded in the Si{sub 3}N{sub 4}, and large SiC particles (100--200 nm) at grain boundary regions (intergranular particles). Amorphous films were found both at Si{sub 3}N{sub 4} and SiC. The Si{sub 3}N{sub 4} grain boundary film thickness varied from 1 to 2.5 nm. Two kinds of embedded SiC particles were observed: type A has a special orientation with respect to the matrix, and type B possesses a random orientation with respect to the matrix. The surfaces of type B particles are completely covered by an amorphous phase. The existence of the amorphous films between the matrix and the particles of type A depends on the lattice mismatch across the interface. The mechanisms of nucleation and growth of {beta}-Si{sub 3}N{sub 4} grains are discussed on the basis of these experimental results.

• Sponsoring Organization: USDOE
• OSTI ID: 230729
• Journal Information: Journal of the American Ceramic Society, Journal Name: Journal of the American Ceramic Society Journal Issue: 3 Vol. 79; ISSN 0002-7820; ISSN JACTAW
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM OXIDES
AMORPHOUS STATE
COMPOSITE MATERIALS
ENERGY-LOSS SPECTROSCOPY
GRAIN BOUNDARIES
MICROSTRUCTURE
ORIENTATION
PARTICLE SIZE
POWDERS
SAMPLE PREPARATION
SILICON CARBIDES
SILICON NITRIDES
SINTERING
TRANSMISSION ELECTRON MICROSCOPY
YTTRIUM OXIDES