Toughness characteristics and associated microstructural behavior in two kinds of SiC and TiB2 particulate-reinforced SiC composites were studied. From indentation-strength tests, the Al2O2-doped, high volume fraction β-SiC/TiB2 showed a distinctive flaw tolerance and a higher retained strength in the long-crack region, as compared with β-SiC alone. On the other hand, the boron- and carbon-doped, low volume fraction, α-SiC/TiB2 exhibited a higher retained strength without an apparent improvement in flaw tolerance, as compared with α-SiC. Crack bridging and sliding and pullout of TiB2 particulates toughened the β-SiC/TiB2, while only crack bridging by TiB2 occurred in α-SiC/TiB2 with difficulty in grain sliding and pullout. A quantitative evaluation of the indentation-strength data revealed a sharp rising toughness curve for β-SiC/TiB2. The enhanced long-crack toughness originated from the weak interface created by the TiB2 and sintering additives.
|Original language||English (US)|
|Number of pages||7|
|Journal||Journal of the European Ceramic Society|
|State||Published - Jan 1 1998|
ASJC Scopus subject areas
- Ceramics and Composites
- Materials Chemistry