Synthesis of Mullite Powder from Alkoxides and Its Properties

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J. Korean Ceram. Soc. > Volume 26(6); 1989 > Article

Journal of the Korean Ceramic Society 1989;26(6): 763.

알콕사이드로부터 Mullite분말의 합성 및 그 특성

이홍림, 함종근¹

연세대학교 공과대학 요업공학과
¹한국과학기술연구원 무기재료연구실a

Synthesis of Mullite Powder from Alkoxides and Its Properties

ABSTRACT

A very fine and pure mullite powder of the stoichiometric composition was prepared from aluminium isopropoxide and tetraethylorthosilicate by an alkoxide hydrolysis method using NH4OH as a catalytic agent. The gel powder obtained from the hydrolysis was calcined at 80$0^{circ}C$ and 125$0^{circ}C$. The average particle sizes of the powders calcined at 80$0^{circ}C$ and 125$0^{circ}C$ were 0.19${mu}{textrm}{m}$ and 0.25${mu}{textrm}{m}$, respectively. The specific surface areas of the powders calcined at 80$0^{circ}C$ and 125$0^{circ}C$ were 114.7$m^2$/g and 20.6$m^2$/g, respectively. The bending strength and fracture toughness of the mullite ceramics sintered at 1$650^{circ}C$ were 263.1MPa and 2.30MPa.m1/2 respectively.