Gelcasting of a rutile mixture applied to extrusion forming

To improve sintering and forming behaviors, many additives are normally included in the rutile powder during extrusion forming. Hence, this complex rutile mixture is difficult to be dispersed into an aqueous solution of acrylamide monomers for gelcasting. In this work, with the aid of a dispersant, the mixture is easy to be dispersed by calcining at high temperature and then ball-milling, and a concentrated rutile suspension with low viscosity was successfully obtained. The suspension can be used to form in-situ a ceramic green body. After sintering the green body, the microstructure and performance of the product are both improved. For example, breakdown strength improved from 12.6 kV/mm to more than 23.6 kV/mm.