ABSTRACT
Since grain growth during sintering is a characteristic feature of polycrystalline ceramics, in this study, we focused on the effect of grain growth on the densification of composites. Rigid dense inclusions that are at least an order of magnitude larger than the average grain size of the matrix material were introduced ( 5, 10, and 20 vol%) into a commercial Zr(Y)O2 powder with very little grain growth during sintering (ZrO2-2.5 mol% Y2O3). The inclusion particles were made from the same powder as the matrix (ZrO2-2.5 mol% Y2O3) in order to avoid any possible compositional changes. The observed densification behavior for constant heating rate and three different isothermal heat-treatments was examined. The constant heating rate experiments showed a delay in sintering for the composites, however, the final densities were comparable, i.e. > 97 %. The isothermal experiments showed a larger reduction in densification to those of the matrix alone. The microstructure showed no signs of excessive grain growth in both the inclusion free matrix and the composite matrix.
