Colloidal Processing and Superplastic Proprties of Fine-Grained Zirconia-Based Ceramics

摘要

Colloidal processing was applied to obtain dense and homogeneous yttria-doped tetragonal zirconia CYTZ), alumina-dispersed YTZ, and magnesia- and titania-doped YTZ. Their slurries were prepared by adding appropriate amounts of polyelectrolyte, and their fine-grained bodies were obtained through slip casting, cold isostatic pressing and low-temperature sintering. The obtained bodies show excellent superplastic properties. In particular alumina addition was found to (1) decrease the limit temperature of superplasticity in YTZ to 1573 K or lower, (2) increase the limit strain rate for large elongation exceeding 300/100 up to 1.2×10~(-2) s~(-1) at 1573 K and (3) large tensile elongation exceeding 1000/100 at 1.7×10~(-4) s~(-1).