METASTABLE ZIRCONIA PHASES PREPARED FROM ZIRCONIUM ALKOXIDE AND YTTRIUM ACETYLACETONATE .2. HOT ISOSTATIC PRESSING OF TETRAGONAL ZIRCONIA SOLID-SOLUTION POWDERS

Metastable ZrO2 (tetragonal) solid solution powders with 2 to 5 mol% Y 2O3 prepared from zirconium isopropoxide and yttrium acetylacetonate h ave been isostatically hot-pressed for 1 h at 1230-degrees-C under 196 MPa. Dense sintered materials with an average grain size of 0.3 mum a re fabricated from powders containing 2 and 2.5 mol% Y2O3. High fractu re toughness (13.5 MPam1/2) and excellent bending strength (1320 MPa) are achieved in these materials. The materials, especially with 5 mol% Y2O3 addition, exhibit high ionic conductivity at high temperatures. The conductivity at 800-degrees-C is evaluated to be 1.8x10(-2) S/CM.