Dense yttria stabilized zirconia: sintering and microstructure

Fine stabilized zirconia powders, which only contain small aggregates, were prepared by a modified Pechini process. These nanocrystalline powders, with an average crystallite size of 20 nm, were used to prepare dense ceramics. Resulting green microstructures and sintering behavior were studied. Green compacts of high green density were prepared by dry pressing and densified by a firing process. During firing, we have shown that dwell temperature and time significantly affected the final grain size and final density. However, a high final density (> 98% ρth) and a final average grain size of 5 μm can be simultaneously achieved by controlling the sintering process. Indeed, the high densification was obtained by minimizing the grain growth that particles undergo when the sample is taken rapidly through the regime temperature in which surface diffusion predominates.