CHARACTERIZATION OF ALUMINA PASTES FOR PLASTIC MOLDING

A better understanding of the parameters controlling the interactions between particle surfaces and water solution would allow an improvemen t of highly concentrated ceramic paste behaviour for use in the extrus ion process, as well as a dramatic decrease of the organic additive co ncentration needed to reach satisfactory plasticity. Therefore, the he at treatment step would also become easier and quicker. Alumina was se lected as a model ceramic powder, and rheological and electrochemical measurements were performed using increasing dry matter content. It wa s shown that, at natural pH, an optimal range of dry matter content ex ists, corresponding to a minimum water content, which can be determine d from plasticity data and from electrochemical measurements. (C) 1996 Elsevier Science Limited.