GRAIN-GROWTH OF DIFFERENTLY DOPED ZIRCONIA

Grain growth has been characterized for various zirconia alloys and cation segregations have been measured with AES and ESCA. The samples were prepared by coprecipitation, followed by compacting and sintering at 1400 degrees C for different times. Grain growth was found to depend strongly on the dopants, e.g. on their radius and valence state. However; segregation factors of these cations did not reveal significant differences. Impurities up to 1 wt% are found to control grain growth via a grain boundary layer. Large amounts of Cr2O3 and SnO2 tend to suppress grain growth effectively by the spherical shaped precipitations. The results are discussed in relation to the existing grain growth models.