TRANSPARENT YTTRIA CERAMICS AND METHOD FOR PRODUCING SAME

摘要

TRANSPARENT YTTRIA CERAMICS AND METHOD FOR PRODUCING SAME An article of manufacture having Application where transparency and resistance to high temperature are required as, for exmaple, in high temperature lamp envelopes is provided comprising a substantially transparent high density polycrystalline yttria-base body consisting essentially of yttria and from about 0.01 to 5 wt. % alumina. A method for preparing the transparent yttria doped with alumina is also provided comprising admixing alumina or a precursor thereof with yttria or a precursor thereof, drying the admixed powders, calcining the admixed powders and pressing the calcined powders into a desired shape and thereafter sintering the shaped powder for about 1/4 to six hours at a temperature above the eutectic temperature at a sufficiently low oxygen atmosphere to prevent oxidative contaminants.