High thermal conductivity in silicon nitride with anisotropic microstructure
- National Industrial Research Inst. of Nagoya (Japan)
Silicon nitride was fabricated by tape casting of {alpha}-Si{sub 3}N{sub 4} powder with 5 wt% Y{sub 2}O{sub 3} and 5 vol% rodlike {beta}-Si{sub 3}N{sub 4} seed particles, followed by tape stacking, hot pressing under 40 MPa, and annealing at 1,850 C for 2--66 h under a nitrogen pressure of 0.9 MPa. Silicon nitrides fabricated by this procedure exhibited a highly anisotropic microstructure with large elongated grains (developed from seed particles) uniaxially oriented parallel to the grain alignment were much higher than those measured in other directions and exhibited high values of up to 120 W/(m{center_dot}K). The anisotropic thermal conductivity of the specimen could be explained by the rule of mixture, considering that large elongated grains developed from seeds have higher thermal conductivity than a small-grained matrix.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 417757
- Journal Information:
- Journal of the American Ceramic Society, Journal Name: Journal of the American Ceramic Society Journal Issue: 9 Vol. 79; ISSN 0002-7820; ISSN JACTAW
- Country of Publication:
- United States
- Language:
- English
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