Effects of the Zr concentration on transparent Y2O3 ceramics fabricated by vacuum pre-sintering and a subsequent HIP treatment

Abstract

Highly transparent Y2O3 ceramics doped with different Zr concentrations were successfully fabricated by vacuum pre-sintering at temperatures ranging from 1600 to 1800 °C combined with a subsequent hot-isostatic pressing (HIP) treatment using commercial powders as the starting materials. All of the 1 mol% Zr-doped Y2O3 ceramics exhibit very good optical quality. The sample with the highest transparency level was realized by vacuum sintering at 1650 °C for 4 h followed by a post-HIP treatment at 1450 °C lasting 5 h. It has a fine microstructure and the grain size is 1.48 µm. Furthermore, the in-line transmittance reaches 83.3% at 1100 nm (1.2 mm thickness). It was found that a relatively low vacuum sintering temperature (1650 °C) and relatively low Zr doping concentration (1 mol%) are more appropriate to achieve optimally transparent Y2O3 ceramics with a subsequent HIP treatment.