Abstract: A method applying a thermal barrier coating to a metal substrate, or for repairing a thermal barrier coating previously applied by physical vapor deposition to an underlying aluminide diffusion coating that overlays the metal substrate. The aluminide diffusion coating is treated to make it more receptive to adherence of a plasma spray-applied overlay alloy bond coat layer. An overlay alloy bond coat material is then plasma sprayed on the treated aluminide diffusion coating to form an overlay alloy bond coat layer. A ceramic thermal barrier coating material is plasma sprayed on the overlay alloy bond coat layer to form the thermal barrier coating. In the repair embodiment of this method, the physical vapor deposition-applied thermal barrier coating is initially removed from the underlying aluminide diffusion coating.

Abstract: The present invention is a process for applying oxide paint as a touch-up paint for an oxide-based corrosion inhibiting coating with at least one imperfection region. Such oxide-based corrosion inhibiting coatings are applied on superalloy components used for moderately high temperature applications, such as the superalloy components found in the high-pressure turbine (HPT) section of a gas turbine engine, including turbine disks and seals. However, during the application of oxide-based corrosion inhibiting coatings, imperfection regions sometimes occur, exposing the superalloy substrate beneath the oxide-based corrosion inhibiting coating. Such imperfection regions can include a spalled region, a scratched region, a chipped region, an uncoated region, or combinations thereof.

Abstract: A method for welding iron-based or nickel-based superalloy assemblies into a unitary article. First, the assemblies are heated in an air atmosphere, at a rate suitable to minimize geometric distortion, to a temperature in the range of about 1400 F (760 C) to about 2000° F. (1090° C.) to form an oxide layer on the surface of the assemblies and optionally as a pre-weld solution heat treat. The temperature of the assemblies are then held in a range of about 1400 F (760 C) to about 2000° F. (1090° C.) for a time sufficient to form an oxide layer of sufficient thickness on the surface of the assemblies and optionally to solution the assemblies. The assemblies are then cooled to ambient temperature at a rate sufficient to avoid precipitation of unwanted metal phases at a rate sufficient to maintain dimensional stability. The oxide layer is then removed from at least the faying surfaces of the assemblies, but not from the face side of the assemblies. The faying surfaces of the assemblies are then cleaned.