Fabrication of transparent Y2O3 ceramics with record-high thermal shock resistance

Sintering-additive-free fine-grained highly transparent Y2O3 ceramics featuring record-high thermal shock resistance were fabricated using commercial powders via vacuum pre-sintering (1375-1550 °C) followed by hot-isostatic pressing (1450 °C). The sample pre-sintered at 1450 °C provides the optimum microstructure for post HIPing, which resulted in a grain size of 0.64 μm. The transmittance, microhardness and fracture toughness of the thus HIPed sample are 80.8% at 1100 nm and 65.5% at 400 nm (1.2 mm thick), 8.0 ± 0.02 GPa and 1.00 ± 0.06 MPa m1/2, respectively. The thermal conductivity increases from 13.1 to 16.5 W/m/K with increasing vacuum pre-sinterin Proc. SPIE-Int. Soc. Opt g temperature from 1450 to 1550 °C. This hybrid sintering method realized high thermal conductivity and high strength simultaneously. Consequently, the thermal shock resistance of the HIPed specimen vacuum pre-sintered at 1450 °C in this work is the highest ever reported to the best of our knowledge, which makes the developed material a promising candidate for high-power laser host and IR dome.