Super-tough silicon nitride with R-curve behavior
Silicon nitride with a fracture toughness of 10.6 + or - 0.5 MPa sq rt m has been developed. This tough, nontransforming ceramic exhibits pronounced R-curve behavior. Double cantilever-beam and indentation/strength measurements were used to characterize the R-curve, and good agreement between the two methods was obtained. The high toughness and R-curve behavior of this silicon nitride material is attributed to extensive crack deflection and crack bridging phenomena arising from its unique microstructure. As a result of R-curve behavior, the material exhibits flaw tolerance and is, therefore, characterized by a high Weibull modulus. Furthermore, this ceramic is more damage-tolerant than silicon nitrides with flat crack growth resistance. 19 refs.
- OSTI ID:
- 6926072
- Report Number(s):
- CONF-890130-; CODEN: CESPD
- Journal Information:
- Ceramic Engineering and Science Proceedings; (USA), Vol. 10; Conference: 13. annual conference on composites and advanced ceramics, Cocoa Beach, FL (USA), 15-18 Jan 1989; ISSN 0196-6219
- Country of Publication:
- United States
- Language:
- English
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