Processing strategy for producing highly anisotropic silicon nitride

Journal Article · Thu Jun 01 00:00:00 EDT 1995 · Journal of the American Ceramic Society

DOI:https://doi.org/10.1111/j.1151-2916.1995.tb08871.x· OSTI ID:82635

Hirao, Kiyoshi; Ohashi, Masayoshi; Brito, M E; Kanzaki, Shuzo ^[1]

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1. National Industrial Research Inst. of Nagoya (Japan)

Silicon nitride with a preferred orientation of large elongated grains was obtained by tape casting of raw powder slurry seeded with rodlike {beta}-Si{sub 3}N{sub 4} particles, followed by a gas pressure sintering under 1 MPa nitrogen pressure. The large elongated grains developed from seeds lay in planes parallel to the casting direction in a two-dimensional distribution. Increased fracture toughness (11.1 MPa {center_dot} m{sup 1/2}) and bending strength (1,100 MPa) were achieved in the direction perpendicular to the grains alignment compared to specimens with a random distribution of elongated grains. Moreover, the specimens exhibited a high Weibull modulus of 46 due to the uniform distribution of large grains.

• Sponsoring Organization: USDOE
• OSTI ID: 82635
• Journal Information: Journal of the American Ceramic Society, Vol. 78, Issue 6; Other Information: PBD: Jun 1995
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
SILICON NITRIDES
CASTING
SINTERING
MICROSTRUCTURE
MECHANICAL PROPERTIES
YTTRIUM OXIDES
ALUMINIUM OXIDES
POWDERS
TOLUENE
BUTANOLS
LAYERS
GRAIN SIZE
GRAIN ORIENTATION
FRACTURE PROPERTIES
FLEXURAL STRENGTH