Journal of the Korean Ceramic Society (한국세라믹학회지)

The Korean Ceramic Society (한국세라믹학회)
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Properties of $\beta$-Sialon Prepared from Korean Natural Resources

한국산 천연원료로부터 $\beta$-Sialon의 합성 및 그 특성

  • 임헌진 (연세대학교 공과대학 요업공학과) ;
  • 이홍림 (연세대학교 공과대학 요업공학과)
  • Published : 1989.03.01
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Abstract

$\beta$-Sialon powder was synthesized by the simultaneous reduction and nitridation of the mixed powder of Hadong kaolin and Kimcheon quartzite, using graphite as a reducing agent. The synthesized $\beta$-Sialon powder (Z=1) was hot-pressed at 175$0^{\circ}C$, for 90min under 30MPa in N2 atmosphere, after Yttria and YAG composition material were added as sintering agents. The effects of grain-boundary crystallization on high-temperature mechanical properties of $\beta$-Sialon ceramics were investigated. Strength degradation was observed at above 1,00$0^{\circ}C$ for the $\beta$-Sialon (Z=1)-8wt% Y2O3 composition, but it was not observed up to 1,20$0^{\circ}C$ for the $\beta$-Sialon-8wt% YAG composition which was annealed at 1,40$0^{\circ}C$ for 4 hours in N2 atmosphere. After the $\beta$-Sialon-8wt% YAG composition was annealed, the decrease of fracture toughness was observed.

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References

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