Rapidly fabricating Y₂O₃ transparent ceramics at low temperature by SPS with mesoporous powder

Abstract

Fine‐grained and dense highly transparent Y2O3 ceramics have been successfully prepared using high sintering activity mesoporous Y2O3 powders without any additive by spark plasma sintering (SPS). The influences of the sintering temperature on microstructure, density, optical, and mechanical properties of SPS‐sintered Y2O3 ceramics were studied in detail. As results, the optimal Y2O3 ceramics with high relative density of 99.90% and fine average grain size of 140 nm were obtained at a low sintering temperature of 1140°C and a moderate load pressure of 60 MPa for 5 min. Meanwhile, the dense Y2O3 ceramics with 1 mm thickness after annealing show a high linear transmittance of 78% (close to 94% of the theoretical value) at 2.4–3 µm wavelength. In additions, the Vickers hardness and fracture toughness of samples can reach 8.48 GPa and 1.45 MPa m1/2, respectively. This result proves that the high activity of mesoporous Y2O3 is considered to be an important means for preparing high‐performance fine Y2O3 ceramics at low sintering temperature.