Ceramics-Silikáty 57 (1) 28-32 (2013)

INFLUENCE OF MANGANESE ON THE SINTERING PROPERTIES OF TETRAGONAL ZIRCONIA

The influence of small additions of MnO₂ (up to 1 wt. %) on the sintering behaviour of yttria-stabilized zirconia sintered over the temperature range from 1250°C to 1500°C was investigated. It was found that the mechanical properties of Y-TZP were dependent on the dopant amount and sintering temperature. The results revealed that relative densities above 97.5 % of theoretical (i.e. > 5.95 Mg m^-3) could be obtained in Y-TZPs sintered at low temperatures, 1250°C and 1300°C, with the additions of ≥ 0.3 wt. % MnO₂. In comparison to the undoped samples, the additions of up to 1 wt. % MnO₂ and for sintering up to 1350°C was found to be beneficial in enhancing the Vickers hardness of the ceramic. The fracture toughness of Y-TZP however, was found to increase only in the 1 wt. % MnO₂-doped samples when sintered above 1400°C. The relation between the measured mechanical properties is discussed with the emphasis on the role of the manganese oxide.

Keywords: Y-TZP, Zirconia, Manganese Oxide, Mechanical Properties