EFFECT OF DRY MIXED GRINDING OF TALC, KAOLINITE AND GIBBSITE ON PREPARATION OF CORDIERITE CERAMICS

The effect of dry mixed grinding of talc, kaolinite and gibbsite using a planetary ball mill on the preparation of cordierite ceramics was investigated by XRD, TG-DTA, SEM, TEM-EDX, EPMA, density and specific surface-area measurements. The structures of talc, kaolinite and gibbsite are easily transformed from crystalline state to amorphous state by grinding within 240 min. This behavior leads to homogeneity in the micro-scale composition of the mixture as well as the aggregation of obtained fine particles. The amount of alpha-cordierite formed in the sintered body is increased with increase in grinding time for the mixture. In addition, alpha-cordierite phase in the sintered body obtained from the ground mixture is crystallized at a relatively lower sintering temperature than that of the unground mixture.