SYNTHESIS AND SINTERING CHARACTERISTICS OF ZIRCONIA AND ZIRCONIA-ALUMINA NANOCOMPOSITES

3 mol% Yttria Stabilized Tetragonal Zirconia (YSTZ) and YSTZ-Alumina n anocomposites were synthesized by a sol-gel synthesis technique using zirconium tetrachloride and hydrated yttrium chloride for YSTZ and zir conium tetrachloride, hydrated yttrium chloride and aluminum chloride for the nanocomposites. After drying and calcining at 823K, the partic le size was in the range 10-25 nm. The powders were sintered using a u niaxial hot press with an applied stress of 20-40 MPa. One hour isothe rmal sintering cycles were performed in air with an initial heating ra te of 50K/min. The sintering behavior and grain coarsening characteris tics were studied using SEM and TEM and the phase structure was determ ined using X-ray diffraction.