In the present work, the effect of manganese oxide (MnO2) additions (0, 0.5, 1 and 5 wt%) on the properties of ceria-doped scandia stabilized zirconia (10Sc1CeSZ) was investigated over the temperature range of 1400 oC to 1550 oC. The results showed that the addition up to 1 wt% had negligible effect on the mechanical properties of the ceramic. The samples containing up to 1 wt% MnO2 attained above 97.5% relative density, Vickers hardness of 13-14 GPa and fracture toughness of about 3MPam1/2. In addition, it was revealed that the 0.5 wt% MnO2 addition was beneficial in suppressing the cubic zirconia grain growth i.e. the highest average grain size was measured at 4.9 μm when sintered at 1550 oC as compared to 9.9 μm measured for the undoped zirconia when sintered at the same temperature. On the other hand, the addition of 5 wt% MnO2 was found to be detrimental to the densification and properties of the zirconia, particularly when sintered at higher temperatures. This was attributed to the accelerated grain growth of the doped samples, i.e. the grain size increased by 2 fold, to 18.6 μm when sintered at 1550 oC.

Keywords: Cubic Zirconia, Ceria-Doped Scandia Stabilized Zirconia, Manganese Oxide Addition, Sintering, Mechanical Propert