Fabrication of ceramic composites consisting of powders with different specific gravity by the slip-casting technique

For composites, it is of great importance to fabricate well-dispersed green compacts, in order to improve their mechanical properties and reliability. In the present study, the slip-casting technique was applied to the fabrication of ZrO2-WC-Al2O3 composites. The specific gravity of each composition in this material was very different, that is, 6.07 for ZrO2, 15.6 for WC and 3.94 for Al2O3. The compositions in the green compacts were afraid to separate from each other owing to the difference in their specific gravities, leading to heterogeneity in the microstructure. The relative density of the obtained compacts was approximately 60%. WC and Al2O3 were well-dispersed in the ZrO2 matrix. The separation and/or heterogeneity due to difference could not be recognized by energy-dispersive X-ray analysis. The slip-casting technique was found to be applicable to the fabrication of ceramic composites consisting of raw powders with different specific gravities.