Characterisation of alumina pastes for plastic moulding

Abstract A better understanding of the parameters controlling the interactions between particle surfaces and water solution would allow an improvement of highly concentrated ceramic paste behaviour for use in the extrusion process, as well as a dramatic decrease of the organic additive concentration needed to reach satisfactory plasticity. Therefore, the heat treatment step would also become easier and quicker. Alumina was selected as a model ceramic powder, and rheological and electrochemical measurements were performed using increasing dry matter content. It was shown that, at natural pH, an optimal range of dry matter content exists, corresponding to a minimum water content, which can be determined from plasticity data and from electro-chemical measurements.