Effect of Manganese Oxide on the Sintered Properties of 8YSZ

The sinterablility of 8 wt. % yttria-stabilized-zirconia (8YSZ) containing different weight ratios of MnO2 as sintering aid was investigated over the temperature range of 1200-1400 °C Relative density, microstructure, microhardness and bending strength as a function of sintering temperature and sintering aid content were investigated. The experiment results show that the addition of MnO2 is effective in aiding densification, and the relative density, microhardness and bending strength of doped samples are generally much higher than those of the undoped samples; the relative density, grain size and microhardness increase with the increasing of sintering temperature and addition content of MnO2; when the additive content of MnO2 is below 3 wt. %, the bending strength increases with the increasing of sintering temperature and addition content of MnO2, sintered at 1300 °Cwith 3 wt. % MnO2 addition, the sample has the maximum bending strength 235.5 MPa, fine grain size and high relative density are two main reasons of the high bending strength and hardness of the materials.