Synthesis and Sintering of Cordierite by using Coprecipitation Method

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J. Korean Ceram. Soc. > Volume 27(7); 1990 > Article

Journal of the Korean Ceramic Society 1990;27(7): 899.

공침법에 의한 Cordierite분말의 합성 및 소결에 관한 연구

한문희, 박금철¹

한국동력자원연구소
¹한양대학교 공과대학 무기재료공학과

Synthesis and Sintering of Cordierite by using Coprecipitation Method

ABSTRACT

The cordierite powders were prepared from Mg(NO3)2.6H2O, Al(NO3)3.9H2O and colloidal silica by the coprecippitation method, and the sintering behavior of the powders were investigated. Two different methods were applied for producing the precursor powders. The one was to added the aqueous solution of Mg(NO3)2.6H2O and Al(NO3)3.9H2O to NH4OH to adjust pH at 10 where the colloidal silica of pH 10 was added. The other wa to add the aqueous solution of Mg(NO3)2.6H2O and Al(NO3)3.9H2O to the colloidal silica with NH4OH to control the final mixture to be at pH 10. It was confirmed that more homogeneous powders were obtained from the latter method. The firing linear shrinkage of the powder compacts fabricated from the calcined powder between 90$0^{circ}C$ and 110$0^{circ}C$ was found to be larger as the calcination temperature was low. But all of them stopped shrinking around 120$0^{circ}C$. The powder compacts, fabricated using the calcined powders at 90$0^{circ}C$ and 95$0^{circ}C$ for 2hours and sintered at 142$0^{circ}C$ for 2hours, showed relative density of 93-96%, 3-point bending strength of 81-83MPa, KIC of 1.9-2.4 MPam1/2 and thermal expansion coefficient of 0.213-0.732$times$10-6$^{circ}C$.