LOWER CONDUCTIVITY THERMAL BARRIER COATING

摘要

A thermal barrier coating for superalloy articles such as turbine engine vanes and blades that are exposed to high temperature gas is disclosed. The coating includes a columnar grained ceramic layer applied to an aluminide or MCrAlY bond coat by electron beam physical vapor deposition. The ceramic layer is comprised a plurality of layers of zirconia stabilized with 20 percent yttria and the interfaces between the layers are decorated with particles selected from a group consisting of Ta2O5 and alumina. Though not essential to the invention a layer of tetragonal zirconia may be deposited both under and over the ceramic coat. An improved electron physical beam vapor deposition process for applying this ceramic layer is also disclosed.