Abstract
A Si3N4-SiO2 composite ceramic was fabricated by using a near net-shape preparation method that was a combined process of oxidation-bonding, sol-gel infiltration and sintering. The relationship of the process, composition, microstructure, and properties of the as-received composite ceramic was discussed in detail. The results indicate that with the increase of SiO2 derives from the sol-gel infiltration and sintering process, the flexural strength, hardness, fracture toughness, density, and dielectric constant all increase. The fracture toughness of the as-received composite ceramic was tested by using the Vickers indentation fracture toughness (VIF) and single-edge notched beam (SENB) methods. Crack deflection, crack branching, crack bridging, and the blunting of pores were detected in the Si3N4-SiO2 composite ceramic when the toughness was measured by the VIF method. However, crack deflection was detected in the Si3N4-SiO2 composite ceramic measured by the SENB method.
Original language | English |
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Pages (from-to) | 769-775 |
Number of pages | 7 |
Journal | Kuei Suan Jen Hsueh Pao/Journal of the Chinese Ceramic Society |
Volume | 36 |
Issue number | 6 |
State | Published - Jun 2008 |
Keywords
- Composite ceramic
- Fracture toughness
- Oxidation bonding
- Silicon nitride
- Sol-gel