| abstract |
A thermal insulating ceramic layer for use in a thermal barrier coating system on a component designed for use in a hostile thermal environment, such as turbine, combustor and augmentor components of a gas turbine engine. The ceramic layer is formed of zirconia stabilized by yttria and characterized by a columnar grain structure in which a monoclinic phase is present. To attain the monoclinic phase, the ceramic layer contains less than six weight percent yttria, with about two to five weight percent yttria being preferred. The ceramic layer is preferably part of a thermal barrier coating system that includes a substrate and a bond coat adhering the ceramic layer to the substrate. To obtain the desired columnar grain structure, the ceramic layer is deposited by a PVD technique, preferably EBPVD. |