High optical quality Y2O3 transparent ceramics with fine grain size fabricated by low temperature air pre-sintering and post-HIP treatment

High optical quality Y 2 O 3 transparent ceramics with fine grain size were successfully fabricated by air pre-sintering at various temperature ranging from 1500 to 1600   °C combined with a post-hot-isostatic pressing (HIP) treatment using co-precipitated powders as the starting material. The fully dense Y 2 O 3 transparent ceramic with highest transparency was obtained by pre-sintered at 1550   °C for 4   h in air and post-HIPed at 1600   °C for 3   h (the pressure of HIP 200   MPa), and it had fine microstructure and the average grain size was 0.96   μm. In addition, the in-line transmittance of the ceramic reached 81.7% at 1064   nm (1   mm thickness). By this approach, the transparent Y 2 O 3 ceramics with fine grain size (<1.6   μm) were elaborated without any sintering aid.