Optical and thermo-mechanical properties of fine-grained transparent yttria ceramics fabricated by hot-press sintering for infrared window applications

摘要

In this work, highly transparent yttria ceramics Phi=55mm in size were fabricated by a hot-pressing method with 1 at.% ZrO2 or 12 at.% La2O3 as a sintering additive. For a 4-mm-thick specimen doped with ZrO2, the in-line transmittance reaches 71.1% at 400nm and 80.9% at 1100 nm, and the transmittance of the La2O3-doped specimen is comparable to that of the ZrO2-doped specimen. By means of the relatively low sintering temperature of 1600 degrees C, the present samples exhibited very fine microstructures (2 mu m), giving rise to excellent mechanical strength levels (similar to 200 MPa). With regard to the 1 at.% ZrO2-doped specimen, the combination of high strength and high thermal conductivity (similar to 10 W/mK) substantially improved parameters related to the thermal shock resistance. The results of this study indicate that the hot-pressed transparent yttria ceramic doped with 1 at.% ZrO2 is optically, mechanically, and thermally suitable for high-temperature IR window applications.