Low-temperature fabrication of zirconia transparent ceramics via hydrothermal nanopowder

Highly sinterable nanopowder of 8 mol% yttria-stabilized cubic zirconia (8YSZ) was synthesized via a hydrothermal homogeneous precipitation (HHP) method. The nanopowder with an average particle size of 26 nm, exhibits good dispersibility, narrow particle size distribution and high purity, making it ideal raw material for preparing transparent ceramics. Utilizing spark plasma sintering (SPS) under mild conditions (1200–1350 °C, 80 MPa, 10 min) in contrast to hot isostatic pressing (HIP), cubic zirconia ceramics with favorable optical and mechanical properties were produced. The sample sintered at 1250 °C achieved the highest transmittance of 74 %@850 nm, significantly surpassing the performance of samples prepared from two other commercial 8YSZ powders. Furthermore, the specimen sintered at 1200 °C with a dense fine microstructure (relative density: 99.51 %, grain size: 460 nm), demonstrated the highest hardness and fracture toughness, reaching 15.72 GPa and 1.28 MPa m^1/2, respectively.