Preparation of Transparent 3 Y ‐ TZP Nanoceramics with No Low‐Temperature Degradation

The progresses of the relative density, average grain size ( GS ), and maximum pore size entering into the final sintering stage are investigated in 3 mol% yttria‐stabilized tetragonal zirconia polycrystals (3 Y ‐ TZP ) compacts in the range of 87%~99% theoretical density. It is found that during conventional pressureless sintering, the pores in the compact enlarged dramatically, which appears to be the major obstacle for preparing fully dense nanoceramics. Transparent 3 Y ‐ TZP nanoceramics with an average GS of 87 nm were prepared by exploiting microstructural refinement on nanoscale. The yields a maximal optical transmittance of 67% and shows no noticeable low‐temperature degradation after 100 h aging at 134°C under a hydrothermal pressure of two bars.