Synthesis and sintering characteristics of zirconia and zirconia-alumina nanocomposites

3 mol% Yttria Stabilized Tetragonal Zirconia (YSTZ) and YSTZ-Alumina nanocomposites were synthesized by a sol-gel synthesis technique using zirconium tetrachloride and hydrated yttrium chloride for YSTZ and zirconium tetrachloride, hydrated yttrium chloride and aluminum chloride for the nanocomposites. After drying and calcining at 823K, the particle size was in the range 10-25 nm. The powders were sintered using a uniaxial hot press with an applied stress of 20-40 MPa. One hour isothermal sintering cycles were performed in air with an initial heating rate of 50K/min. The sintering behavior and grain coarsening characteristics were studied using SEM and TEM and the phase structure was determined using X-ray diffraction.