Effect of Ultrasonication on the Microstructure and Tensile Elongation of Zirconia-Dispersed Alumina Ceramics Prepared by Colloidal Processing

To obtain dense, fine-grained ceramics, fine particles and advanced powder processing, such as colloidal processing, are needed. Al₂O₃ and ZrO₂ particles are dispersed in colloidal suspensions by electrosteric repulsion because of polyelectrolyte absorbed on their surfaces. However, additional redispersion treatment such as ultrasonication is required to obtain dispersed suspensions because fine particles tend to agglomerate. The results demonstrate that ultrasonication is effective in improving particle dispersion in suspensions and producing a homogeneous fine microstructure of sintered materials. Superplastic tensile ductility is improved by ultrasonication in preparing suspensions because of the dense and homogeneous fine microstructure.