Microstructure refinement and mechanical properties improvement of HfB2–SiC composites with the incorporation of HfC

De Wei Ni, Ji-Xuan Liu, Guo-Jun Zhang

Research output: Contribution to journalJournal articleResearchpeer-review

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 languageEnglish
JournalJournal of the European Ceramic Society
Volume32
Issue number10
Pages (from-to)2557-2563
ISSN0955-2219
DOIs
Publication statusPublished - 2012
Externally publishedYes

Keywords

  • Hot pressing
  • Mechanical properties
  • Hafnium diboride
  • UHTCs
  • Synthesis

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