Fabrication, optical transmittance, and hardness of IR-transparent ceramics made from nanophase yttria

Commercially available nanophase yttria powder was used to fabricate a transparent ceramic and its optical transmittance and hardness were measured. The nanophase yttria powder was dry-pressed without the use of any binders. Subsequently, the green body was sintered in air, hot-isostatically pressed, and polished, resulting in an IR-transparent ceramic. Scanning electron microscopy revealed a grain size of 21.5 ± 11.1 μm. Optical transmittance reached about 60% at 1 μm, and hardness measurements showed 792 HK100 g, 704 HK500 g, and 767 HV100 g.