Investigation of Nano-Cr2O3 Addition on the Properties of Mullie-Zirconia Composites

In this study, mullite-zirconia composites were fabricated by reaction-sintering method. Besides, the slip casting was used for forming of these composites. Then, the effect of nano-Cr2 3 addition on the properties of these composites was investigated and the results were compared with microsized Cr2O3. Hence, the physical and mechanical properties, phase composition and the microstructure of these composites were investigated. The result showed that Cr2O3 can reduce porosity and increase density by the formation of liquid phase which, the nano-sized type has higher effect. Besides, 0.5 wt.% Cr2O3 can increase the bending strength of composite which, the nano-sized type is effective than other. The height amount of this additive can produce high content of amorphous phase and then decrease of bending strength. On the other hand, the grain size of zirconia tends to decreasing due to liquid phase formation. Corresponding to XRD results addition of Cr2O3 can reduce amount of tetragonal phase which, the nano-sized type is effective than other.