Abstract: A method for applying a NiAl based bond coat and a diffusion aluminide coating to a metal substrate is disclosed. The method comprises providing a superalloy substrate, the superalloy substrate having an external surface; and optionally cleaning the external surface of the superalloy substrate. The method further comprises coating a portion of the external surface of the superalloy substrate, by physical vapor deposition with a layer of a NiAl based metal alloy, wherein the deposited NiAl based metal alloy includes a controlled amount of about 6 to 25 weight percent aluminum and additionally the deposited aluminum level of the NiAl based metal alloy is controlled to be about 50-100% of its final level after aluminizing to form a coated external portion; and subsequently, simultaneously aluminizing the coated external portion and a different surface of the superalloy substrate.

Abstract: Apparatus for electroplating a workpiece includes an unassembled electroplating anode assembly having weldable first and second structural anode members. The first structural anode member includes a positioning slot. The second structural anode member includes a positioning tab disposable in the positioning slot. A method for making an electroplating anode assembly includes obtaining an electroplating-anode-assembly first structural anode member having a positioning slot and obtaining an electroplating-anode-assembly second structural anode member having a positioning tab. The method also includes locating the positioning tab in the positioning slot and welding together the first and second structural anode members.

Abstract: A method for applying a NiAl based bond coat and a diffusion aluminide coating to a metal substrate comprises, in part, coating a portion of the external surface of the superalloy substrate, by physical vapor deposition with a layer of a NiAl based metal alloy, wherein the deposited NiAl based metal alloy includes a controlled amount of about 6 to 25 weight percent aluminum, wherein the deposited aluminum level of the NiAl based metal alloy is controlled to be about 50-100% of its final level after aluminizing to form a coated external portion; and subsequently, simultaneously aluminizing the coated external portion and a different surface of the superalloy substrate.

Abstract: Methods for coating a turbine engine rotor component involving depositing at least one platinum group metal selected from platinum, palladium, rhodium, ruthenium, iridium and osmium on the rotor component, and heating the rotor component to a temperature of from about 500° C. to about 800° C.

Abstract: A method for adjusting the airflow in a turbine component having a plurality of airflow holes. The method comprises the step of depositing an overlay metallic coating on the surface of the turbine component in a manner such that at least some of the airflow holes are partially filled such that the volume of the partially filled airflow holes is changed so as to adjust the airflow through the turbine component. Also provided is a turbine component having a plurality of airflow holes, at least some of the airflow holes being partially filled with the overlay metallic coating to change the volume thereof so as to adjust the airflow through the turbine component.

Abstract: A turbine engine rotor component, such as a compressor or turbine disk or seal element, is protected from corrosion by depositing an aluminum or chromium coating on the component. The deposition can be performed by a vapor deposition process, such as metal organic chemical vapor deposition (MOCVD), to a coating thickness of from about 0.2 to about 50 microns, typically from about 0.5 to about 3 microns. In one embodiment, the method is conducted in a vapor coating container having a hollow interior coating chamber, and includes the steps of loading the coating chamber with the component to be coated; and flowing a tri-alkyl aluminum or chromium carbonyl coating gas into the loaded coating chamber at a specified temperature, pressure, and time to deposit an aluminum or chromium coating on the surface of the component. The coated component is then heated in a nonoxidizing atmosphere to a specified temperature to form an aluminide or chromide coating on the surface.

Abstract: A process for removing aluminosilicate-based material (e.g., “CMAS”) from a substrate is described. The material is treated with an aqueous composition containing at least one acid having the formula HxAF6, in which A is Si, Ge, Ti, Zr, Al, and Ga; and x is 1-6. Treatment of the substrate is often carried out by immersion in an aqueous bath. The process is also very effective for removing CMAS-type material from cavities in the substrate, e.g., cooling holes in a gas turbine component. Related compositions are also described.

Abstract: A process for removing aluminosilicate-based material (e.g., “CMAS”) from a substrate is described. The material is treated with an aqueous composition containing at least one acid having the formula HXAF6, in which A is Si, Ge, Ti, Zr, Al, and Ga; and x is 1-6. Treatment of the substrate is often carried out by immersion in an aqueous bath. The process is also very effective for removing CMAS-type material from cavities in the substrate, e.g., cooling holes in a gas turbine component. Related compositions are also described.

Abstract: A method of removing a ceramic coating (18), and particularly zirconia-containing thermal barrier coating (TBC) materials such as yttria-stabilized zirconia (YSZ), that has been either intentionally or unintentionally deposited on the surface of a component (10). The method entails subjecting the ceramic coating (18) to an aqueous solution containing an acid fluoride salt, such as ammonium bifluoride (NH4HF2) or sodium bifluoride (NaHF2), and a corrosion inhibitor. The method is capable of completely removing the ceramic coating (18) without removing or damaging the underlying substrate material, which may include a metallic bond coat (16).

Abstract: A method of removing a ceramic coating (18), and particularly zirconia-containing thermal barrier coating (TBC) materials such as yttria-stabilized zirconia (YSZ), that has been either intentionally or unintentionally deposited on the surface of a component (10). The method entails subjecting the ceramic coating (18) to an aqueous solution containing an acid fluoride salt, such as ammonium bifluoride (NH4HF2) or sodium bifluoride (NaHF2), and a corrosion inhibitor. The method is capable of completely removing the ceramic coating (18) without removing or damaging the underlying substrate material, which may include a metallic bond coat (16).