Ceria and yttria codoped tetragonal zirconia (Ce,Y-ZrO2)/alumina composites containing 5-30 mol.-% alumina were fabricated by low temperature sintering at 1200-1400°C using powders prepared by crystallising amorphous gel precursors in supercritical methanol at 250°C for 5 h and supercritical drying. Two compositions, one containing 10.8 mol.-%CeO2 and 0.2 mol.-%Y2O3, designated (10.8Ce, 0.2Y)-ZrO2, and the other containing 9.0 mol.-%CeO2 and 0.75 mol.-%Y2O3, designated (9Ce,0.75Y)-ZrO2, were used as end members for the preparation of the composites. The addition of alumina inhibited grain growth of zirconia during sintering and reduced the sinterability but improved the thermal stability of tetragonal zirconia in moist atmospheres. The fracture strength and fracture toughness values of (10.8Ce,0.2Y)-ZrO2/Al2O3 composites were higher than those for (9Ce,0.75Y)-ZrO2/Al2O3. Composites of (10.8Ce,0.2Y)-ZrO2/5-10 mol.-%Al2O3 sintered at 1300°C for 5 h possessed excellent fracture strength, fracture toughness, and thermal stability of the tetragonal phase in moist atmosphere.
|Number of pages||6|
|Journal||British Ceramic Transactions|
|Publication status||Published - 1998 Dec 1|
ASJC Scopus subject areas
- Ceramics and Composites