Abstract: A thermal barrier coating system for high temperature nickel-based and cobalt-based superalloys includes a hardenable metallic coating on the substrate and a ceramic topcoat. The metallic coating is preferably a gamma/gamma prime hardenable nickel-based superalloy, and the ceramic topcoat is preferably zirconium oxide having from about 6 to about 20 percent yttrium oxide or from about 15 to about 40 percent cerium oxide. Optionally, there may be provided between the hardenable metallic layer and the ceramic topcoat an intermetallic coating such as a nickel aluminide.

Abstract: A thermal barrier coating system for high temperature superalloys includes an intermetallic bond coating on the substrate and a ceramic topcoat having a columnar grain structure with the columnar axis perpendicular to the surface of the coating. The intermetallic coating is preferably a nickel aluminide or a platinum aluminide, whose upper surface is oxidized during processing to form a thin layer of predominantly aluminum oxide. The ceramic topcoat is preferably zirconium oxide having from about 6 to 20 percent yttrium oxide.