Journal of the Korean Ceramic Society (한국세라믹학회지)

The Korean Ceramic Society (한국세라믹학회)
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Densification and Crystallization Characteristics of LAS Gels Prepared by the Hydrolysis-Condensation Reaction and the Mixed Colloidal Processing Route

가수분해-축합반응 및 콜로이드 혼합법으로 유도된 LAS gel의 치밀화와 결정화 특성

  • 김광수 (전남대학교 공과대학 무기재료공학과) ;
  • 장현명 (포항공과대학 재료공학과 정밀세라믹스 공정과학 연구실) ;
  • 정창주 (전남대학교 공과대학 무기재료공학과)
  • Published : 1991.11.01
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Abstract

LAS (lithium aluminosilicate) sol was synthesized using the hydrolysis-condensation reaction of TEOS, chelated Al(OBus)3 and LiNO3 with H2O in alcohol (ethanol+2-propanol) medium. Lowering Li content by a factor of 1/2 significantly enhanced densification and retarded the crystallization of LAS gel by ~30$0^{\circ}C$. Dense LAS specimen with essentially pore-free microstructure was obtained by sintering the sol-gel derived gel at 80$0^{\circ}C$ for 4 h and annealing at 120$0^{\circ}C$ for 2 h. Similary, a mixed colloidal processing was attempted as a convenient, alternative route for the fabrication of dense LAS sintered body. The $\beta$-spodumene seeding (~0.8 ${\mu}{\textrm}{m}$) in the sol-gel derived LAS modified the sequence of phase transformations and lowered the temperature of crystallization by ~12$0^{\circ}C$. Combining the epitaxial seeding with the sol-gel process, we could lower the crystallization temperature to the sintering temperature range (~80$0^{\circ}C$) and, demonstrate a possibility of making the viscous sintering/crystallization as a continuous as a continuous unit process.

Keywords

References

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