Facile Fabrication of Highly Transparent Yttria Ceramics with Fine Microstructures by a Hot-Pressing Method

In this study, we report highly transparent yttria ceramics fabricated by a facile hot-pressing method with tantalum foil shielding which effectively prevents the ceramic samples from carbon contamination caused by the graphite mold used during the process. The hot-pressed sample was already highly transparent without a post-annealing step or hot isostatic pressing. For a 2-mm-thick specimen doped with 1at.% ZrO2, the in-line transmittance reaches 74.4% at 400nm and 81.1% at 1100nm. The sample shows a very fine microstructure with an average grain size of about 1m owing to the low sintering temperature of only 1600 degrees C. The study results indicate that it is possible to produce transparent yttria ceramics with excellent optical transparency using the economical and convenient hot-pressing method.