Abstract: A coating analysis system and method inductively heat a component having a coating. Optionally, the component is heated while a cooling fluid flows through cooling holes extending through the component and the coating. The system and method measure rates of infrared radiation emission from the component and the coating at different locations on the component and the coating. The system and method determining bond qualities (e.g., tensile strengths of bonds) between the coating and the component at the different locations based on the rates of infrared radiation emission that are measured.

Abstract: A coating analysis system and method inductively heat a component having a coating. Optionally, the component is heated while a cooling fluid flows through cooling holes extending through the component and the coating. The system and method measure rates of infrared radiation emission from the component and the coating at different locations on the component and the coating. The system and method determining bond qualities (e.g., tensile strengths of bonds) between the coating and the component at the different locations based on the rates of infrared radiation emission that are measured.

Abstract: Turbine airfoil components with protective layers and methods therefore. The components are each formed to have a platform, an airfoil extending upwardly from the platform, and a shank extending downwardly from the platform. The shank has an exterior wall and an internal passage, and the airfoil has a cooling flow channel inside the airfoil for flowing a cooling flow therethrough. The component has an interior chromide coating contacting at least a portion of an interior surface of the shank and interdiffused with a base metal thereof, and an exterior chromide coating contacting at least a portion of an exterior surface of the shank and interdiffused with the base metal thereof. The interior and exterior chromide coatings do not have an aluminide coating deposited thereon.

Abstract: A thermal barrier coating and deposition process for a component intended for use in a hostile thermal environment, such as the turbine, combustor and augmentor components of a gas turbine engine. The TBC has a first coating portion on at least a first surface portion of the component. The first coating portion is formed of a ceramic material to have at least an inner region, at least an outer region overlying the inner region, and a columnar microstructure whereby the inner and outer regions comprise columns of the ceramic material. The columns of the inner region are more closely spaced than the columns of the outer region so that the inner region of the first coating portion is denser than the outer region of the first coating portion, wherein the higher density of the inner region promotes the impact resistance of the first coating portion.

Abstract: Methods for coating a substrate includes depositing on the substrate, a inner bond coat layer of a bond coat composition comprising, in weight percent, 14-20% Cr, 5-8% Al, 8-12% Co, 3-7% Ta, 0.1-0.6% Hf, 0.1-0.5% Y, up to about 1% Si, 0.005-0.020% Zr, 0.04-0.08% C, 0.01-0.02% B, with a remainder including nickel (Ni) and incidental impurities, wherein the bond coat composition is substantially free of rhenium; forming an aluminum-containing layer overlying the inner bond coat layer; and, optionally, depositing a thermal barrier coating composition overlying the aluminum-containing layer.

Abstract: Coated superalloy article includes a bond coat comprising an inner bond coat layer disposed on the first surface being formed by deposition of a bond coat composition comprising, in weight percent, 14-20% Cr, 5-8% Al, 8-12% Co, 3-7% Ta, 0.1-0.6% Hf, 0.1-0.5% Y, up to about 1% Si, 0.005-0.020% Zr, 0.04-0.08% C, 0.01-0.02% B, with a remainder including nickel (Ni) and incidental impurities, wherein the bond coating composition is substantially free of rhenium. An aluminum-containing layer overlies the inner bond coat layer. Optionally, a thermal barrier coating overlies the aluminum-containing layer, wherein the thermal barrier coating, if present, is formed by deposition of a thermal barrier coating composition.

Abstract: A gas turbine blade comprises a base metal, a platform, an airfoil extending upwardly from the platform, a shank extending downwardly from the platform. The shank has an exterior wall and an internal passage, and the airfoil has a cooling flow channel inside the airfoil for flowing a cooling flow therethrough. The blade has a first chromide coating contacting the base metal of at least a portion of an interior surface of the shank and interdiffused therewith, wherein the first chromide coating does not have an aluminide coating deposited over it. The blade has a second chromide coating contacting the base metal of at least a portion of an interior surface of the airfoil and interdiffused therewith. A method for preparing a gas turbine blade comprises the steps of applying chromide coatings, sealing the interior passages of the shank and airfoil and applying an aluminide or platinum aluminide coating and an optional ceramic layer on the airfoil.

Abstract: A method for selectively removing an aluminide coating from at least one surface of a metal-based substrate by: (a) contacting the surface of the substrate with at least one stripping composition comprising nitric acid at a temperature less than about 20° C. to degrade the coating without damaging the substrate; and (b) removing the degraded coating without damaging the substrate. Also disclosed is a method for replacing a worn or damaged aluminide coating on at least one surface of a metal-based substrate by selectively removing the coating using the above steps, and then applying a new aluminide coating to the surface of the substrate. Turbine engine parts, such as high-pressure turbine blades, treated using the above methods are also disclosed.

Abstract: A method is provided for repairing a surface portion of an article including a metallic environmental resistant coating on a substrate. The coating includes a coating outer portion bonded with the substrate through a diffusion zone that includes at least one feature, for example Al and/or an intermetallic phase, in an amount detrimental to application of a metallic replacement coating and/or repair of the article. The method comprises removing the coating outer portion to expose a surface of the diffusion zone. The substrate and the diffusion zone are heated at a temperature and for a time sufficient to diffuse and/or dissolve at least a portion of the at least one feature in the exposed surface and in a portion of the diffusion zone beneath the exposed surface to a level below the detrimental amount. This provides a replacement surface portion integral with diffusion zone. Then a metallic replacement coating outer portion is applied to the replacement surface portion.

Abstract: A method for applying an aluminide coating on a gas turbine engine blade having an external surface and an internal cooling cavity having an internal surface that is connected to the external surface by cooling holes. 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 blade to be coated; providing an aluminide coating gas in the loaded coating chamber; maintaining the loaded coating chamber comprising the aluminide coating gas at a specified temperature and time to deposit an aluminide coating on the external surface of the blade; and then flowing an inert carrier gas into the loaded coating chamber comprising the aluminide coating gas at a specified gas flow rate and time to move the aluminide coating gas through the cooling holes and internal cooling cavity and deposit an aluminide coating on the internal surface of the blade.

Abstract: A method for selectively removing an aluminide coating from at least one surface of a metal-based substrate by: (a) contacting the surface of the substrate with at least one stripping composition comprising nitric acid at a temperature less than about 20° C. to degrade the coating without damaging the substrate; and (b) removing the degraded coating without damaging the substrate. Also disclosed is a method for replacing a worn or damaged aluminide coating on at least one surface of a metal-based substrate by selectively removing the coating using the above steps, and then applying a new aluminide coating to the surface of the substrate. Turbine engine parts, such as high-pressure turbine blades, treated using the above methods are also disclosed.

Abstract: A method enables a gas turbine engine blade to be manufactured to include an airfoil, a platform, a shank, and a dovetail. The platform extends between the airfoil and the shank, the shank extends between the dovetail and the platform, and the dovetail includes at least one tang for securing the blade within the engine. The method comprises defining a cooling cavity in the blade that extends through the airfoil, the platform, the shank, and the dovetail, such that a portion of the cavity defined within the dovetail includes a root passage portion having a first width, and a transition portion extending between the root passage and the portion of the cavity defined within the shank, and wherein the portion of the cavity defined within the shank has a second width that is larger than the root passage first width. The blade is then coated with an environmental resistive coating.

Abstract: A method for applying an aluminide coating on a gas turbine engine blade having an external surface and an internal cooling cavity having an internal surface that is connected to the external surface by cooling holes. 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 blade to be coated; providing an aluminide coating gas in the loaded coating chamber; flowing an inert carrier gas into the loaded coating chamber comprising the aluminide coating gas at a specified gas flow rate and time to move the aluminide coating gas through the cooling holes and internal cooling cavity and deposit an aluminide coating on the internal surface of the blade; and then flowing an inert carrier gas into the loaded coating chamber comprising the aluminide coating gas at a specified higher temperature and time to deposit an aluminide coating on the external surface of the blade.

Abstract: An article is coasted by preparing a coating source having an aluminum halide, a fluoride or an iodide of a modifying element as a source of the modifying element, and a carrier gas. The modifying element is zirconium, hafnium, and yttrium, or combinations thereof. The coating source is contacted to the article, and the coating source and the article are heated to a coating temperature of at least about 1850° F. for a period of time sufficient to permit aluminum and the modifying element to coat onto the surface of the article. The preferred fluorides of modifying elements are zirconium tetrafluoride and hafnium tetrafluoride.

Abstract: A method for applying an aluminide coating on a gas turbine engine blade having an external surface and an internal cooling cavity having an internal surface that is connected to the external surface by cooling holes. 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 blade to be coated; providing an aluminide coating gas in the loaded coating chamber; flowing an inert carrier gas into the loaded coating chamber comprising the aluminide coating gas at a specified gas flow rate and time to move the aluminide coating gas through the cooling holes and internal cooling cavity and deposit an aluminide coating on the internal surface of the blade; and then flowing an inert carrier gas into the loaded coating chamber comprising the aluminide coating gas at a specified higher temperature and time to deposit an aluminide coating on the external surface of the blade.

Abstract: A method for applying an aluminide coating on a gas turbine engine blade having an external surface and an internal cooling cavity having an internal surface that is connected to the external surface by cooling holes. 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 blade to be coated; providing an aluminide coating gas in the loaded coating chamber; maintaining the loaded coating chamber comprising the aluminide coating gas at a specified temperature and time to deposit an aluminide coating on the external surface of the blade; and then flowing an inert carrier gas into the loaded coating chamber comprising the aluminide coating gas at a specified gas flow rate and time to move the aluminide coating gas through the cooling holes and internal cooling cavity and deposit an aluminide coating on the internal surface of the blade.

Abstract: A method enables a gas turbine engine blade to be manufactured to include an airfoil, a platform, a shank, and a dovetail. The platform extends between the airfoil and the shank, the shank extends between the dovetail and the platform, and the dovetail includes at least one tang for securing the blade within the engine. The method comprises defining a cooling cavity in the blade that extends through the airfoil, the platform, the shank, and the dovetail, such that a portion of the cavity defined within the dovetail includes a root passage portion having a first width, and a transition portion extending between the root passage and the portion of the cavity defined within the shank, and wherein the portion of the cavity defined within the shank has a second width that is larger than the root passage first width. The blade is then coated with an environmental resistive coating.

Abstract: A method is provided for repairing a surface portion of an article including a metallic environmental resistant coating on a substrate. The coating includes a coating outer portion bonded with the substrate through a diffusion zone that includes at least one feature, for example Al and/or an intermetallic phase, in an amount detrimental to application of a metallic replacement coating and/or repair of the article. The method comprises removing the coating outer portion to expose a surface of the diffusion zone. The substrate and the diffusion zone are heated at a temperature and for a time sufficient to diffuse and/or dissolve at least a portion of the at least one feature in the exposed surface and in a portion of the diffusion zone beneath the exposed surface to a level below the detrimental amount. This provides a replacement surface portion integral with diffusion zone. Then a metallic replacement coating outer portion is applied to the replacement surface portion.

Abstract: A method is provided for repairing a surface portion of an article including a metallic environmental resistant coating on a substrate. The coating includes a coating outer portion bonded with the substrate through a diffusion zone that includes at least one feature, for example Al and/or an intermetallic phase, in an amount detrimental to application of a metallic replacement coating and/or repair of the article. The method comprises removing the coating outer portion to expose a surface of the diffusion zone. The substrate and the diffusion zone are heated at a temperature and for a time sufficient to diffuse and/or dissolve at least a portion of the at least one feature in the exposed surface and in a portion of the diffusion zone beneath the exposed surface to a level below the detrimental amount. This provides a replacement surface portion integral with diffusion zone. Then a metallic replacement coating outer portion is applied to the replacement surface portion.

Abstract: A gas turbine engine includes a blade including a leading edge, a trailing edge, a first sidewall extending in radial span between a blade root and blade tip, and a second sidewall connected to the first sidewall at the leading edge and at the trailing edge. The first and second sidewalls each include an outer surface and an inner surface. A cooling cavity is defined by the first sidewall inner surface and the second sidewall inner surface. At least a portion of the cooling cavity is coated with an oxidation resistant environmental coating that has a thickness less than 0.0015 inches.