Ni-base superalloy having a thermal barrier coating system

摘要

An article (10) and TBC coating system (20) thereon that in combination exhibit significantly improved spallation resistance. The article (10) comprises a substrate (22) formed of a metal alloy containing ruthenium and one or more refractory elements (e.g., tantalum, tungsten, molybdenum, rhenium, hafnium, etc.). The substrate (22) is protected by a coating system (20) comprising an aluminum-containing bond coat (24) on the surface of the substrate (22) and a ceramic coating (26) bonded to the substrate (22) by the bond coat (24). The bond coat (24), preferably an aluminide, is deposited so as to be substantially free of ruthenium, though ruthenium is present in the bond coat (24) as a result of diffusion from the substrate (22) into the bond coat (24).