Abstract
HfB2 and HfB2–10vol% HfC fine powders were synthesized by carbo/boronthermal reduction of HfO2, which showed high sinterability. Using the as-synthesized powders and commercially available SiC as starting powders, nearly full dense HfB2–20vol% SiC (HS) and HfB2–8vol% HfC–20vol% SiC (HHS) ceramics were obtained by hot pressing at 2000°C/30MPa. With the incorporation of HfC, the grain size of HHS was much finer than HS. As well, the fracture toughness and bending strength of HHS (5.09MPam1/2, 863MPa) increased significantly compared with HS (3.95MPam1/2, 654MPa). Therefore, it could be concluded that the incorporation of HfC refined the microstructure and improved the mechanical properties of HfB2–SiC ceramics.
Original language | English |
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Journal | Journal of the European Ceramic Society |
Volume | 32 |
Issue number | 10 |
Pages (from-to) | 2557-2563 |
ISSN | 0955-2219 |
DOIs | |
Publication status | Published - 2012 |
Externally published | Yes |
Keywords
- Hot pressing
- Mechanical properties
- Hafnium diboride
- UHTCs
- Synthesis