Fabrication of fine-grained undoped Y2O3 transparent ceramic using nitrate pyrogenation synthesized nanopowders

Y2O3 ceramic is a promising optical material for mid-infrared (IR) windows and domes. Improvements in the mechanical and thermal performance of this material have become urgent if it is to perform adequately under extreme conditions. Herein, Y2O3 nanopowders were produced through the nitrate pyrogenation method. The final Y2O3 transparent ceramics were fabricated with a hybrid sintering method combining low temperature presintering and a subsequent hot isostatic pressing (HIP) treatment. The synthesis of nanopowders and the fabrication of the final ceramic products were investigated in detail. The Y2O3 ceramic sample that was presintered at 1350 degrees C provided the optimum microstructure for HIP treatment and resulted in an average grain size of 0.5 mu m. Owing to the reduced grain size, the flexure strength and Vickers hardness of the sample were improved to 180 MPa and 8.4 GPa, respectively. Furthermore, the achieved pure Y2O3 ceramic demonstrated an excellent thermal conductivity at high temperature.