Fabrication of ZrO2-Ti composites by slip casting method

Abstract

Slip casting is one of the most popular shaping method in ceramic technology which allows producing a large number of elements in small period of time. This shaping technique gives a possibility to fabricate ceramic or composite materials such as ZrO2-Ti. Ti with its properties (low density, high melting point, high-temperature strength, good corrosion resistance and others) combine with ZrO2 (high flexure strength, high compression resistance and very high KIC) can be considered for different applications as constructional and functional materials. For the preparation of such composite nanometric zirconium oxide powder stabilized by 3 mol% Y2O3 and micrometric titanium powder were used. Water-based slurries with 35, 40, 45 and 50 vol.% solid phase content were prepared with 3, 10 and 15 vol.% addition of titanium powder. Zeta potential and pH of prepared slurries were considered. The pH changes were tested as a function of Ti content. The viscosity of the prepared slurries was measured. The sedimentation tests for selected slurries were performed. The casting rate for slurry of 35% solid phase with 10 vol.% Ti was examined. These measurements showed good stability of slurries. With the increasing of the solid phase concentration the density of the green bodies increased. However, the increase of the content of Ti powder reduced the density of green body samples. For selected samples the SEM observations was carried out. Composites produced by slip casting were characterized by a homogenous distribution of Ti particles in the ZrO2 matrix.