Processing and characterization of Ca-TZP nanoceramics

The aim of this work was to prepare the calcia–zirconia nanopowder by method eliminating the problem of calcium ions losses. Therefore, a physical mixing of zirconia gel and calcium hydroxide was employed to obtain a precursor of the partially calcium oxide stabilized zirconia nanopowder. The mixture was calcined at 500 °C for 1 h in air. 4 mol% CaO–ZrO2 nanopowder of tetragonal and monoclinic symmetry in the amount of 91.5% and 8.5%, respectively, average crystallites of 10 nm and specific surface area of about 117.6 m2/g was obtained. The second aim was to manufacture the calcium oxide stabilized tetragonal zirconia nanoceramics. The 4Ca-TZP sintered bodies with 100% of tetragonal symmetry, relative density above 99% and average grains size of 112.4 nm were manufactured by pressureless sintering for 2 h at 1200 °C in air. The sintered material shows a bending strength of about 730 MPa and is resistant to low-temperature degradation.