摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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. Provided is a coated article comprising a substrate and a metallic environmental resistant coating bonded with the substrate. The coating comprises an inner modified portion of the substrate integral with the substrate, an outer diffusion zone integral with the inner portion, and a metallic environmental resistant coating outer portion integral with the outer diffusion zone. In some forms, the coated article includes a thermal barrier coating over the metallic coating outer portion.
摘要:
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.
摘要:
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. Provided is a coated article comprising a substrate and a metallic environmental resistant coating bonded with the substrate. The coating comprises an inner modified portion of the substrate integral with the substrate, an outer diffusion zone integral with the inner portion, and a metallic environmental resistant coating outer portion integral with the outer diffusion zone. In some forms, the coated article includes a thermal barrier coating over the metallic coating outer portion.
摘要:
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).
摘要:
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.
摘要:
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.