Kinetics of [Beta]-Si[sub 3]N[sub 4] grain growth in Si[sub 3]N[sub 4] ceramics sintered under high nitrogen pressure

Journal Article · Fri Jan 01 04:00:00 EST 1993 · Journal of the American Ceramic Society; (United States)

DOI:https://doi.org/10.1111/j.1151-2916.1993.tb03693.x· OSTI ID:6470302

Lai, Kou Rueh; Tien, Tseng Ying ^[1]

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

The kinetics of anisotropic [beta]-Si[sub 3]N[sub 4] grain growth in silicon nitride ceramics were studied. Specimens were sintered at temperatures ranging from 1,600 to 1,900C under 10 atm of nitrogen pressure for various lengths of time. The results demonstrate that the grain growth behavior of [Beta]-Si[sub 3]N[sub 4] grains follows the empirical growth law D[sup n] [minus] D[sup n][sub o] = kt, with the exponents equaling 3 and 5 for length [001] and width [210] direction, respectively. Activation energies for grain growth were 686 kJ/mol for length and 772 kJ/mol for width. These differences in growth rate constants and exponents for length and width directions are responsible for the anisotropy of [Beta]-Si[sub 3]N[sub 4] growth during isothermal grain growth. The resultant aspect ratio of these elongated grains increases with sintering temperature and time.

• OSTI ID: 6470302
• Journal Information: Journal of the American Ceramic Society; (United States), Journal Name: Journal of the American Ceramic Society; (United States) Vol. 76:1; ISSN 0002-7820; ISSN JACTAW
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201* -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
360202 -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
ANISOTROPY
CERAMICS
CHEMICAL REACTION KINETICS
COHERENT SCATTERING
COMPACTS
DIFFRACTION
FABRICATION
GRAIN BOUNDARIES
GRAIN GROWTH
KINETICS
MEDIUM PRESSURE
MICROSTRUCTURE
NITRIDES
NITROGEN COMPOUNDS
PELLETS
PNICTIDES
POWDERS
REACTION KINETICS
SCATTERING
SILICON COMPOUNDS
SILICON NITRIDES
SINTERING
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE
TEMPERATURE RANGE 1000-4000 K
TIME DEPENDENCE
X-RAY DIFFRACTION