Optimization of the rheological properties of alumina slurries for ceramicprocessing applications - Part I: Slip-casting

Aqueous powder slurries are widely employed in ceramic manufacturing proces ses like slip-casting and spray-drying. The aim of the present work was to identify the conditions for the preparation of stable alumina slurries with high solids content for the production of slip-cast objects with improved properties. as well as to correlate the slurry properties to the final obje ct properties. For slurry stabilization, three commercial dispersants were compared. It was found that for each dispersant there exists an optimum con centration range within which low viscosity is achieved for a slurry of hig h solids content. In addition to the slurry solids content, the choice of a particular dispersant also affects the slurry viscosity and through that t he casting rate. The combination of high slurry solids content and slower c asting rate results in objects with higher densities both in the green and fired state. (C) 2001 Published by Elsevier Science Ltd. All rights reserve d.