Alumina/silicon carbide nanocomposites by hybrid polymer/powder processing: Microstructures and mechanical properties
- Univ. of Oxford (United Kingdom). Dept. of Materials
Nanocomposites with fine, coarse, and bimodal silicon carbide (SiC) particle-size distributions were hot pressed and examined by transmission electron microscopy, scanning electron microscopy, and optical microscopy, as well as by four-point-bend and indentation tests. The finer SiC nanophase was introduced homogeneously by coating a silicon-containing polymer onto the alumina (Al{sub 2}O{sub 3}) powder, followed by a pyrolysis procedure; for the coarser SiC, nanophase conventional powder processing was used. Powder- and polymer-processed nanocomposites both had their maximum strengths at 5 vol% of SiC. High-strength nanocomposites that contained a higher volume fraction of SiC could be fabricated when the two methods were combined in a hybrid processing route. The SiC phase in the resulting hybrid materials originated from both the polymer and the SiC powder. The mechanical properties of these materials could be correlated with the fabrication route. Processing-flaw populations and calculated Griffith-flaw sizes were not only smaller, but they were also significantly different in the nanocomposites, in comparison to those in Al{sub 2}O{sub 3} ceramics; this may explain the strength increase in Al{sub 2}O{sub 3}/SiC nanocomposite materials.
- Sponsoring Organization:
- New Energy and Industrial Technology Development Organization, Tokyo (Japan)
- OSTI ID:
- 616207
- Journal Information:
- Journal of the American Ceramic Society, Journal Name: Journal of the American Ceramic Society Journal Issue: 1 Vol. 81; ISSN 0002-7820; ISSN JACTAW
- Country of Publication:
- United States
- Language:
- English
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