Packing of oxide ceramic powders by centrifugal casting

Topical commercially available powders of silica, zinc oxide, tin oxide, and alumina were centrifugally cast. The purpose of the study was to determine the feasibility of centrifugal casting well-dispersed slips of such ceramic oxide powders to obtain high green densities and to observe the effects that deviations from an ideal monodisperse, spherical powder have on the resulting packing density. The powders were characterized by particle size distributions and microscopy. Viscosity versus pH data were obtained for those powders for which there was a sufficient quantity. The results generally showed a good correlation of centrifugal casting density with the degree of powder dispersion as measured by viscosity. However, the packing densities obtained were not higher than those which can be obtained by conventional slip casting or dry pressing. It can be concluded that centrifugal casting of typical ceramic powders does not offer any advantage over other consolidation processes.