Abstract: A method and apparatus for forming a coating on a surface of a superalloy substrate area of a gas turbine engine component, and the component produced by the method, includes providing a slurry with selected metal powders suspended in a silane containing solution, applying the slurry by brushing, spraying or 3D printing using a piezoelectric dot matrix printhead to the superalloy substrate, drying the applied slurry, and depending on the aluminum content desired in the coating, including a sufficient amount of aluminum in the slurry or aluminiding the coated component. The method and apparatus can be used to obtain components having different superalloy coating thicknesses or compositions in different areas of the component based on the particular operating environment for each area with a single heat treatment and/or aluminiding cycle for obtaining the different coatings.

Abstract: A method of forming a metallic wetting layer on the surface of a metal component is provided, including the steps of placing the component into a chemical vapor deposition furnace, placing a metal-containing salt in the furnace, and heating the component and the metal-containing salt in the furnace to cause the metal from the metal-containing salt to deposit in a coating on the surface of the component forming a metallic wetting layer that improves the metallic bond of a subsequently applied brazing material. The process can be practiced with the addition of a cleaning reagent to both clean and coat in one operation.

Abstract: Apparatus and methods for removing coatings from metal components, such as metal components used in aircraft and other aerospace vehicles and the oil industry, as well as aqueous bath compositions. The metal component may be DC coupled with a counter electrode and immersed in an aqueous bath that includes an active oxygen source and a ligand in a composition effective to remove the coating. The aqueous bath may include hydrogen peroxide as the active oxygen source and may be maintained in a specific pH range if the temperature of the aqueous bath is controlled. In an alternative embodiment, the composition of the aqueous bath may include a non-peroxide active oxygen source, such as sodium perborate, and be maintained in a different specific pH range. An oxygen sensor may be provided to periodically monitor the concentration of active oxygen in the aqueous bath.

Abstract: Methods for cleaning surface deposits, such as sulfidation deposits or dust particles, from a surface bounding an internal passage in a turbine engine component. The surface deposits are cleaned by placing a halogen-containing organic compound, such as a fluorine-containing organic compound, into the internal passage and heating the component and organic compound to chemically react the halogen-containing species in the liquefied and boiling organic compound with the deposits. The temperature is further elevated to vaporize the chemically-modified deposits, which are moved by mass transport through the internal passage and out of the turbine engine component. An optional protective coating, such as a chromium or aluminum coating, may be applied to the cleaned surface of the internal passage.

Abstract: Methods for removing coatings from metal components, such as metal components used in aircraft and other aerospace vehicles and the oil industry. The method may include removing an outer layer of a coating with a first stripping operation, removing an inner layer of the coating with a second stripping operation, and specifying an aqueous bath for either the first stripping process based upon an element in the outer layer or the second stripping process based upon an element in the inner layer.

Abstract: Compositions and methods for treating metal substrates and/or bonding metal substrates to polymeric materials, such as rubber, are provided. The compositions include at least one substantially hydrolyzed amino silane and at least one substantially hydrolyzed sulfur-containing silane. Optionally, the compositions include a nano-size particulate material. The compositions provide coatings on metal substrates for protecting the metal from corrosion and for adhering rubber-like polymeric compositions to the metal with polymer-to-metal vulcanization conditions less dependent on the coating thickness, and with use of less coating materials.

Abstract: Apparatus and methods for removing coatings from metal components, such as metal components used in aircraft and other aerospace vehicles and the oil industry, as well as aqueous bath compositions. The metal component may be DC coupled with a counter electrode and immersed in an aqueous bath that includes an active oxygen source and a ligand in a composition effective to remove the coating. The aqueous bath may include hydrogen peroxide as the active oxygen source and may be maintained in a specific pH range if the temperature of the aqueous bath is controlled. In an alternative embodiment, the composition of the aqueous bath may include a non-peroxide active oxygen source, such as sodium perborate, and be maintained in a different specific pH range. An oxygen sensor may be provided to periodically monitor the concentration of active oxygen in the aqueous bath.

Abstract: A metal component (10) with a protective coating (16) containing silicon and a process for forming such protective coatings (14). The protective coating (16) is formed by applying a silicon-containing fluid composition to the metal component (10) as a silicon-containing layer (12) and heating the silicon-containing layer (12) to a temperature exceeding 400° F.

Abstract: A gas turbine engine component (10) with an aluminide coating (42) on at least a portion of an airflow surface (18) that includes a roughening agent (44) effective to provide a desired surface roughness and a deposition process for forming such aluminide coatings (42). A layer (40) including a binder (38) and the roughening agent (44) maybe applied to the superalloy substrate (46) of the component (10) and the aluminide coating (42) formed on the airflow surface portion by exposing the component (10) and layer (40) to an appropriate deposition environment. Suitable roughening agents include metal and ceramic particles (44) that are dispersed on the airflow surface portion before exposure to the deposition environment. The particles (44), which are substantially intact after the aluminide coating (42) is formed, are dispersed in an effective number to supply the desired surface roughness.

Abstract: A chemical vapor deposition (CVD) system and method for applying an aluminide coating constituted by two or more extrinsic metal components on a jet engine component. The aluminide coating is capable of forming a protective complex oxide upon subsequent heating in an oxidizing environment. At least one of the extrinsic metals in the aluminide coating is provided as a first vapor phase reactant from a receptacle coupled by a closed communication path with the reaction chamber of the CVD system and free of a carrier gas. The aluminide coating is formed by the chemical combination of the first vapor phase reactant with a second vapor phase reactant either created in situ in the reaction chamber or supplied by a carrier gas to the reaction chamber from a precursor source.

Abstract: A turbine engine component (10) with a protective aluminide coating (14) that include additions of silicon and a dopant, such as yttrium and/or hafnium, in an amount effective to reduce sulfidation and a deposition process for forming such aluminide coatings (14). A silicon-containing layer (30) may be applied to the superalloy substrate (12) of the component (10) and the aluminide coating (14) formed by exposing component (10) and layer (30) to a vapor phase reactant containing the dopant. The aluminide coating (14), which contains dopant from the layer (30), may operate as a standalone environmental coating or as a bond coating for an optional ceramic thermal barrier layer (24). An optional zirconia layer (26) maybe provided between the aluminide coating (14) and the ceramic thermal barrier layer (24).

Abstract: A chemical vapor deposition (CVD) system and method for applying an aluminide coating constituted by two or more extrinsic metal components on a jet engine component. The aluminide coating is capable of forming a protective complex oxide upon subsequent heating in an oxidizing environment. At least one of the extrinsic metals in the aluminide coating is provided as a first vapor phase reactant from a receptacle coupled by a closed communication path with the reaction chamber of the CVD system and free of a carrier gas. The aluminide coating is formed by the chemical combination of the first vapor phase reactant with a second vapor phase reactant either created in situ in the reaction chamber or supplied by a carrier gas to the reaction chamber from a precursor source.

Abstract: A turbine engine component (10) with a non-aluminide protective coating (14) containing silicon and chromium and a process for forming such non-aluminide protective coatings (14). The non-aluminide protective coating (14) is formed by applying a silicon-containing fluid composition to the turbine engine component (10) as a silicon-containing layer (20) and heating the silicon-containing layer (20) to a temperature effective to form the non-aluminide protective coating (14).

Abstract: Methods for cleaning surface deposits, such as sulfidation deposits or dust particles, from a surface bounding an internal passage in a turbine engine component. The surface deposits are cleaned by placing a halogen-containing organic compound, such as a fluorine-containing organic compound, into the internal passage and heating the component and organic compound to chemically react the halogen-containing species in the liquefied and boiling organic compound with the deposits. The temperature is further elevated to vaporize the chemically-modified deposits, which are moved by mass transport through the internal passage and out of the turbine engine component. An optional protective coating, such as a chromium or aluminum coating, may be applied to the cleaned surface of the internal passage.

Abstract: Apparatus and methods for removing tungsten-containing coatings from metal components, such as metal components used in aircraft and other aerospace vehicles. The metal component is DC coupled with a counter electrode and immersed in an aqueous bath that includes an active oxygen source and a ligand in a composition effective to remove the tungsten-containing coating. The aqueous bath may be maintained at a pH greater than about 7.0 and less than or equal to about 8.0. A sensor may be provided to periodically monitor the oxidation reduction potential of the aqueous bath. Another sensor may be provided to periodically monitor the pH of the aqueous bath.

Abstract: Aluminide coatings or layers (14) for jet engine components (10) and a process for forming aluminide layers (14) that include additions of silicon and yttrium. A superalloy substrate (12) of the component (10) is initially coated with a layer of a silicon-containing material. The substrate (12) is then aluminided, for example by a chemical vapor deposition process, and is exposed to a yttrium-containing material during the aluminiding process to form the aluminide layer (14) containing silicon and yttrium. A ceramic thermal barrier layer (24) of yttria-stabilized zirconia may be optionally applied over the aluminide layer (14). Another optional zirconia layer (26) maybe provided between the aluminide layer (14) and the ceramic thermal barrier layer (24). The present invention provides a silicon- and yttrium-containing aluminide layer (14) having improved durability, either as a standalone environmental coating or as a bond coat for a subsequently-applied ceramic thermal barrier layer (24).

Abstract: A chemical vapor deposition (CVD) system and method for applying an aluminide coating constituted by two or more extrinsic metal components on a jet engine component. The aluminide coating is capable of forming a protective complex oxide upon subsequent heating in an oxidizing environment. At least one of the extrinsic metals in the aluminide coating is provided as a first vapor phase reactant from a receptacle coupled by a closed communication path with the reaction chamber of the CVD system and free of a carrier gas. The aluminide coating is formed by the chemical combination of the first vapor phase reactant with a second vapor phase reactant either created in situ in the reaction chamber or supplied by a carrier gas to the reaction chamber from a precursor source.

Abstract: A system and process for cleaning a hollow interior or a passageway of a metal member including an external container having counter electrode material with a higher potential than the metal member with the counter electrode material being dc coupled to the metal member, and electrolyte passing through the container to contact the counter electrode material and fluidicly coupled into the hollow interior or the passageway of the metal member to clean same.

Abstract: A leach column (10) and method for the separation and recovery of metals from mixtures. The column (10) is adapted to be electrically charged to enhance metal recovery. Particularly, a pair of electrical connections (20), (22) are positioned in the column (10) to create an electrical charge in the presence of a leaching solution (18) and a metal-containing mixture (26) to enhance leaching of the metal from the mixture. In an exemplary embodiment, the leach column (10) is used for the recovery of platinum from platinum-containing coatings on jet engine components.

Abstract: A system and process for chemical milling or stripping a surface portion and/or surface deposit from metal products, such as chemically milling a metal to remove surface defects and/or stripping non-metallic deposits from a metal surface. The metal product is associated with an electrolyte, such as by being immersed in a tank filled with the electrolyte, such as a diluted acid mixture. A counter electrode having a higher potential than the metal of the metal product is also associated with the electrolyte. The counter electrode is dc coupled to the metal product, or to a conductive component in direct contact with the metal product, such that electric current flows from the metal to the counter electrode due to the difference in the natural potentials of the metal and the counter electrode. The surface portion or deposit is thereby stripped or milled from the metal product.