Abstract
ZrSiO4 powders were prepared using a sol-gel processing from partially hydrolyzed Si(OC2H5)4 and Zr(WC3H7)4 solutions. The optimum conditions for obtaining precursor gels with ZrSiO4 composition were as follows: concentration of mixed solutions; 0.25mol/l, stirring time of alkoxide solutions: 6h, pH of the hydrolysis water: 5.5, H2O/alkoxide molar ratio: 10 and stirring time of solutions after hydrolysis: 3h. The precursor powders prepared by using these conditions were converted into ZrSiO4 powders in about 20% yield at 1200°C for 2h by the addition of 1.5wt% ZrSiO4 seeds. Furthermore, the formation rate of ZrSiO4 became remarkably higher through “Hedvall effect” bringing about the transition from amorphous silica to crystalline silica at 1250°-1350°C, and the powders prepared by firing at 1500°C for 2h have become an almost single phase of ZrSiO4 and the particle size of 0.3-0.6μm is revealed.
