General Electric Company

Jeffrey Allen Conner

Joseph David Rigney

Michael James Weimer

Roger Dale Wustman

Nripendra Nath Das

Jonathan Philip Clarke

Jon Conrad Schaeffer

David John Wortman

Thomas Edward Mantkowski

Bangalore Aswatha Nagaraj

Wayne Charles Hasz

John Frederick Ackerman

William Randolph Stowell

Bhupendra Kumar Gupta

Antonio Frank Maricocchi

John Matthew Powers

Lyle Timothy Rasch

John Peter Heyward

Warren Davis Grossklaus, Jr

Mark Alan Rosenzweig

Thomas Froats Broderick

Howard John Farr

David Vincent Rigney

John Douglas Evans, Sr

Dennis Paul Dry

Michael Beverley

Joseph Howell Bowden, Jr

Joseph A Heaney, Iii

Janet Elizabeth Gaewsky

Timothy Lane Norris

David G W Fargher

Gregory J Anselmi

Elissa H Lee

David C Zigan

William E Brummett, Ii

Patricia A Zomcik

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.

Coated article and method for repairing a coated surface

A method is provided for refurbishing a service operated metallic coating on a substrate alloy, the coating including at least within a coating outer surface at least one oxide chemically grown from at least one coating element, for example Al, and chemically bonded with the coating outer surface as a result of thermal exposure during service operation. Growth of the oxide has depleted at least a portion of the coating element from the coating. The method comprises removing the oxide from the coating outer surface while substantially retaining the metallic coating, thereby exposing in the coating outer surface at least one surface void that had been occupied by the oxide. The retained metallic coating is mechanically worked, substantially without removal of the retained coating, to close the void, providing a treated metallic coating surface over which a refurbishing coating is applied. In one form, the mechanical working provides, concurrently, a compressive stress in the substrate alloy beneath the metallic coating.

Gas turbine engine component having a refurbished coating including a thermally grown oxide

Coating article and method for repairing a coated surface

A method of repairing a thermal barrier coating on a component designed for use in a hostile thermal environment, such as turbine, combustor and augmentor components of a gas turbine engine. The method is particularly suited for completely removing a thermal insulating ceramic layer of thermal barrier coating system that includes a metallic bond coat, such as a diffusion aluminide or MCrAlY coating, between the surface of the component and the ceramic layer, while leaving the bond coat substantially undamaged. Furthermore, the method of this invention includes a technique by which ceramic material within cooling holes in the component can be removed without damaging the underlying bond coat. The process steps generally include removing the ceramic layer from the surface of the component by subjecting the ceramic layer to a caustic solution at an elevated temperature and pressure, and then removing ceramic material from the cooling hole by carefully directing a high-velocity fluid stream into the cooling hole. According to this invention, the high-velocity fluid stream is able to overcome the compressive stresses that otherwise anchor the ceramic in the cooling hole, yet does not remove or damage the bond coat underlying the ceramic.

Method for repairing a thermal barrier coating

An article includes a substrate and an adhesion layer overlying the substrate. The adhesion layer includes a first phase including particles, and a second phase including braze alloy that bonds the particles to the substrate. The article further includes a ceramic layer overlying the adhesion layer. In one embodiment, the ceramic layer is a thermal barrier coating (TBC), formed of stabilized zirconia (ZrO ).

Method for forming a thermal barrier coating system

A thermal barrier coating (TBC) system and method for forming the TBC system on a component designed for use in a hostile thermal environment, such as superalloy turbine, combustor and augmentor components of a gas turbine engine. The TBC system exhibits improved spallation resistance as a result of having a bond coat formed to contain a dispersion of oxide particles in its outer surface region. A method for preferentially entrapping oxide particles in a bond coat entails depositing the oxide particles on the surface of the component prior to forming the bond coat, which may be a diffusion aluminide or an aluminized overlay coating. Deposition of the bond coat causes the oxide particles to become dispersed in the outer surface region of the bond coat. A particular feature of this invention is the ability to preferentially entrap oxides of elements that are not present in the bond coat or a substrate region of the component on which the bond coat is formed.

Thermal barrier coating system with improved bond coat

Method for refurbishing a coating including a thermally grown oxide

A thermal barrier coating system and a method for forming the coating system on a component designed for use in a hostile thermal environment, such as superalloy turbine, combustor and augmentor components of a gas turbine engine. The method is particularly directed to a thermal barrier coating system that includes a thermal insulating ceramic layer and a diffusion aluminide bond coat on which an aluminum oxide scale is grown to protect the underlying surface of the component and to chemically bond the ceramic layer. The bond coat is formed to contain an additive metal of platinum, palladium, rhodium, chromium and/or silicon, and an additive element of yttrium and/or zirconium, with possible additions of hafnium. The bond coat may be formed by codepositing aluminum with the active element, or by depositing the additive metal and active element on the surface of the component, and then aluminizing to form the diffusion aluminide bond coat.

Diffusion aluminide bond coat for a thermal barrier coating system and method therefor

A method is provided for enhancing to a selected coating range a substantially unused protective coating, including aluminum, on an article surface, for example an airfoil surface of a gas turbine engine turbine blade. The protective coating is enhanced without removing such unused coating. The unused coating is evaluated to identify at least one coating region that deviates from the selected coating range by being deficient in at least one of chemistry and physical condition, for example thickness. At least the coating region is enhanced to the selected coating range by applying over the identified coating region at least one secondary element selected from Pt, Rh, Pd, Cr, Si, Hf, Zr, and Y. At least the coating region is heated to diffuse the secondary element into the protective coating to provide a treated coating region. Then at least the treated coating region is aluminided.

Enhancement of an unused protective coating

A coated article is provided with a coating stabilizing portion in a coating combination on a substrate of the article. The coating combination includes a coating diffusion portion on the substrate and an outer coating portion outwardly from the coating diffusion portion. The coating stabilizing portion is provided between the coating diffusion portion and the outer coating portion to inhibit diffusion of undesirable elements to an interface with the outer coating portion and to enhance mechanical properties.

Coated article with internal stabilizing portion and method for making

A process for forming a diffusion aluminide coating on a substrate, such as a component for a gas turbine engine. The process generally entails placing the substrate in a suitable coating chamber, flowing an inert or reducing gas into and through the coating chamber, and then aluminizing the substrate using an aluminizing technique with a substantially constant aluminum activity, such as a vapor phase deposition process. During the aluminizing process, the amount of unreacted aluminum within the coating chamber is controlled by altering the flow rate of the gas through the coating chamber so that a portion of the unreacted aluminum is swept from the coating chamber by the gas. The amount of unreacted aluminum swept from the coating chamber is regulated by metering the gas flow rate in order to control the aluminizing rate and aluminum content of the resulting aluminide coating.

Method of controlling thickness and aluminum content of a diffusion aluminide coating

A method for removing products of hot corrosion and oxidation from selective portions of surfaces of a gas turbine engine, such as coatings and substrates, following exposure of the surfaces to hot oxidative gases of the turbine exhaust. The method involves a high temperature chemical reaction and has no detrimental effect on adjacent coatings and substrates that have not been attacked by the hot exhaust gases.

Method for locally removing oxidation and corrosion product from the surface of turbine engine components

A gas turbine engine hot section component having a ceramic thermal barrier coating is repaired by removing the ceramic thermal barrier coating, removing oxidation products and corrosion products from the metallic bond coating beneath the ceramic thermal barrier coating, applying a noble metal to the component, diffusing the noble metal into the component substrate, and aluminiding the component to provide an outermost noble metal-Al layer.

Repair of coated turbine components

A method for restoring a protective coating including a metallic environmental resistant coating of a coating total thickness within a coating design thickness range on a metal substrate of an article includes the application of a replacement material to at least one discrete local surface area on which an undesirable amount of degradation has occurred. Such degradation can extend through the protective coating into the metal substrate. The degradation product can include at least one of oxidation, coating rumpling, and coating voiding, for example, rumpling or voiding of a bond coat under a ceramic thermal barrier coating (TBC). The degradation product first is conditioned at the discrete local area to expose an underlying portion while retaining at least a portion of the metallic environmental coating on surface areas adjacent the discrete surface area. Then a replacement metallic environmental resistant material is applied, retaining the coating total thickness within the coating design thickness range. If the protective coating includes a TBC, a replacement TBC then is applied over the replacement material.

Repair of a discrete selective surface of an article

A method for preventing the deposition of material in an opening near a surface of an article, and a masking insert therefore. The method and insert are particularly suited for preventing the plating of a metal, such as platinum, on turbine airfoils or turbine blades and vanes having a complex geometry, as is the case when cast trailing edge cooling slots are present in the airfoil surface. The method entails the use of the masking insert, which is precisely configured to mask the cooling slots during plating by preventing circulation of the plating bath through the slots. For this purpose, the insert is equipped with appendages that are sized, shaped, spaced and oriented on a base member to register with, and preferably be received within, the cooling slots of an airfoil having a particular cooling slot design.

Device for preventing plating of material in surface openings of turbine airfoils

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Hamilton, OH, United States of America

Jeffrey Allen Conner