Fine Particle Dispersion and their Influence on Filtration Forming and Sintering Processing

Abstract

Commercially available ceramic powders may contain granules due to limitation in the powder processing. Preparation of highly dispersed ceramic slurry from the powder requires pretreatment using mechanical agitation with sonification. Fine particle in aqueous medium also has another problem in which the fines tend to form larger particles by agglomeration. In this study, the influence of granules/agglomerates on filtration forming and sintering processing were examined. This study focused on zircon (ZrSiO 4 ) granules (<250−µm), which were subjected to mechanical agitation with sonification at pH 7 with and without dispersant, and both mechanical and chemical pretreatment at pH 11. A dependence of pretreatment in the behavior during filtration compaction and sintered densities was found. Highly dispersed ceramic slurry could be obtained by chemical pretreatment using a dispersant (tetra sodium pyrophosphate) at pH 11. The highly dispersed slurry led to producing of a high particle compaction during filtration forming and a high density of sintered sample.