M. Awano et H. Takagi, SYNTHESIS OF CORDIERITE AND CORDIERITE-ZRSIO4 COMPOSITE BY COLLOIDAL PROCESSING, Journal of Materials Science, 29(2), 1994, pp. 412-418
Cordierite powder of high purity and cordierite-ZrO2 composite powder
were synthesized by colloidal processing. Cordierite was synthesized b
y calcining a precursor gel obtained by gelation and coprecipitation o
f AlOOH sol, SiO2 sol and Mg(NO3)(2). The calcination temperature affe
cted the constituent phases in the powders. The phase assemblage in ca
lcined powder affected the sintering conditions. The optimum sintering
temperature of the powder with cordierite single phase was 1440-1450
degrees C when it was calcined at 1270 degrees C. The sintered body ha
d a dense microstructure with submicrometre grains. Addition of ZrO2 s
ol resulted in reaction with cordierite to form mostly ZrSiO4 at the s
intering temperature. Several properties of cordierite and cordierite-
ZrSiO4 composite, such as thermal expansion coefficient, bending stren
gth, dielectric constant and insulation properties at high temperature
, were investigated. Thermal expansion and electric properties were de
graded by an increasing amount of ZrO2 additive, whereas the bending s
trength was improved by the addition of ZrO2.