Centrifugal Deairing of Concentrated Ceramic Slurries

Although there are many investigations in the field of bubble dynamics in various scientific fields, this subject has never been fundamentally studied in the field of ceramic slurries. In this work, a mechanism for bubble formation was proposed, and the elimination of bubbles under a centrifugal field was modeled and formulated. Bubbles were divided into intra-agglomerate and interagglomerate/free categories, and the dynamics were predicted by Stokes' law, which has been proven to be applicable for small bubbles. According to the theory of centrifugal deairing and available formulations for centrifugal casting, the behavior of bubbles in mono-dispersed slurries with various solid contents was evaluated and the change in the slurry property during centrifugation was determined. Finally, it was revealed that the bubbles in ceramic slurries with sizes above 20 mu m can be effectively eliminated by centrifugal deairing without a significant change in the slurry properties and material loss.