Application of gelcasting to the fabrication of piezoelectric ceramic parts

Gelcasting is a novel method for the molding of ceramic powder based on a synthesis of concepts derived from traditional ceramics and polymer chemistry. Although a wealth of literature has been published describing the application of the technology to the fabrication of structural ceramics, little has been reported about its application to the fabrication of functional ceramics. In order to extend the technology to the fabrication of piezoelectric ceramics in this article the colloidal chemistry of PZT powders in aqueous solution, the rheological behavior of the PZT suspension and the influence of dispersants on the rheology of the suspension and on the electrical properties of the gelcast PZT samples are investigated. Because the electrical properties of PZT are very sensitive to the chemical composition of the sample, unsuitable selected dispersants can result in the deterioration of the electric properties of the material although concentrated PZT slurry with low viscosity can be obtained by different dispersants.