Abstract: A thermal barrier coating for an underlying metal substrate of articles that operate at, or are exposed to, high temperatures, as well as being exposed to environmental contaminant compositions. This coating comprises an optional inner layer nearest to the underlying metal substrate comprising a non-alumina ceramic thermal barrier coating material in an amount up to 100%, and an outer layer having an exposed surface and comprising at least about 50% of a non-alumina ceramic thermal barrier coating material and alumina in an amount up to about 50% and sufficient to protect the thermal barrier coating at least partially against environmental contaminants that become deposited on the exposed surface. This coating can be used to provide a thermally protected article having a metal substrate and optionally a bond coat layer adjacent to and overlaying the metal substrate.

Abstract: Coating systems suitable for protecting components exposed to high-temperature environments, such as the hot gas flow path through a gas turbine engine. A multilayer thermal barrier coating (TBC) system characterized by a low coefficient of thermal conductivity and having a heat-absorbing topcoat comprised of the thermal decomposition product of at least one metallic element and at least one ceramic precursor binder component.

Abstract: A turbine engine component comprising a substrate made of a nickel-base or cobalt-base superalloy, a non-metallic oxide or nitride diffusion barrier layer overlying the substrate, and a protective coating overlying the barrier layer, the protective coating comprising at least one platinum group metal selected from the group consisting of platinum, palladium, rhodium, ruthenium and iridium. The diffusion barrier layer may be a deposited or thermally grown oxide material, especially aluminum oxide. The protective coating may be heat treated to increase homogeneity of the coating and adherence with the substrate. The component typically further comprises a ceramic thermal barrier coating overlying the protective coating. Also disclosed are methods for forming a protective coating system on the turbine engine component by forming the non-metallic oxide or nitride diffusion barrier layer on the substrate and then depositing the platinum group metal on top of the barrier layer.

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 high temperature gas turbine component for use in the gas flow path that comprises a specular optical reflector coating system. A thin specular optical reflector coating system is applied to the gas flow path of the component, that is, the surface of the component that forms a boundary for hot combustion gases. The component typically includes a thermal barrier coating overlying the high temperature metallic component that permits the component to operate at elevated temperatures. The thermal barrier coating must be polished in order to provide a surface that can suitably reflect the radiation into the gas flow path. The thin reflector coating system comprises a thin high temperature and corrosion resistant refractory stabilizing layer, which is applied over a thin reflective metal layer, which is applied over a thin high temperature and corrosion resistant refractory sealing layer.

Abstract: A high temperature splash plate for use in the combustor of a gas turbine engine that also is a specular optical reflector. A thin layer of a high temperature reflector is applied to the surface of the splash plate of the component that forms a boundary for hot combustion gases. The component typically includes a thermal barrier coating overlying the high temperature metallic component that permits the component to operate at elevated temperatures. The thermal barrier coating must be polished in order to provide a surface that can suitably reflect the radiation into the gas flow path. A thin layer of the high temperature reflector then is applied over the polished thermal barrier coating by a process that can adequately adhere the reflector to the polished surface without increasing the roughness of the surface. The surface reflects radiation in the direction of the turbine back into the hot gas flow path. The reflected radiation is not focused onto any other hardware component.

Abstract: A combustor for a gas turbine engine includes a deflector assembly that enhances heat transfer from the combustor and minimizes low cycle fatigue stresses induced within the combustor. The deflector assembly includes a plurality of deflectors secured to a spectacle plate. Each deflector has tapered edges and includes a plurality of cylindrical projections extending outward from the deflector to facilitate heat transfer. The projections include rounded edges and are arranged in a high density pattern. The deflector is coated with a thermal barrier coating and a bondcoat to minimize exposure to hot combustion gases or flame radiation.

Abstract: A method for forming an aluminide coating on a turbine engine component having an external surface and an internal cavity defined by an internal surface that is connected to the external surface by at least one hole. 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; flowing a tri-alkyl aluminum coating gas into the loaded coating chamber at a specified temperature, pressure, and time to deposit an aluminum coating on the external and internal surfaces of the component; and heating the component in a nonoxidizing atmosphere at a specified temperature and time to form an aluminide coating on the external and internal surfaces. The coated component is typically then maintained at an elevated temperature in the presence of oxygen to form an oxide coating on the external and internal surfaces of the component.

Abstract: A high temperature gas turbine component for use in the gas flow path that also is a specular optical reflector. A thin layer of a high temperature reflector is applied to the flow path surface of the component, that is, the surface of the component that forms a boundary for hot combustion gases. The component typically includes a thermal barrier coating overlying the high temperature metallic component that permits the component to operate at elevated temperatures. The thermal barrier coating must be polished in order to provide a surface that can suitably reflect the radiation into the gas flow path. A thin layer of the high temperature reflector then is applied over the polished thermal barrier coating by a process that can adequately adhere the reflector to the polished surface without increasing the roughness of the surface. The high temperature reflector can be applied to any surface aft of the compressor, such as on a combustor wall. The surface reflects radiation back into the hot gas flow path.

Abstract: A high temperature gas turbine component for use in the gas flow path that also is a specular optical reflector. A thin layer of a high temperature reflector is applied to the gas flow path of the component, that is, the surface of the component that forms a boundary for hot combustion gases. The component typically includes a thermal barrier coating overlying the high temperature metallic component that permits the component to operate at elevated temperatures. The thermal barrier coating must be polished in order to provide a surface that can suitably reflect the radiation into the gas flow path. A thin layer of the high temperature reflector the is applied over the polished thermal barrier coating by a process that can adequately adhere the reflector to the polished surface without increasing the roughness of the surface. The high temperature reflector can be applied to any surface aft of the compressor, such as on a turbine nozzle. The surface reflects radiation back into the hot gas flow path.

Abstract: A high temperature gas turbine component for use in the gas flow path that also is a specular optical reflector. A thin layer of a high temperature reflector is applied to the gas flow path of the component, that is, the surface of the component that forms a boundary for hot combustion gases. The component typically includes a thermal barrier coating overlying the high temperature metallic component that permits the component to operate at elevated temperatures. The thermal barrier coating must be polished in order to provide a surface that can suitably reflect the radiation into the gas flow path. A thin layer of the high temperature reflector the is applied over the polished thermal barrier coating by a process that can adequately adhere the reflector to the polished surface without increasing the roughness of the surface. The high temperature reflector can be applied to any surface aft of the compressor, such as on a centerbody.

Abstract: A combustor for a gas turbine engine includes a deflector assembly that enhances heat transfer from the combustor and minimizes low cycle fatigue stresses induced within the combustor. The deflector assembly includes a plurality of deflectors secured to a spectacle plate. Each deflector has tapered edges and includes a plurality of cylindrical projections extending outward from the deflector to facilitate heat transfer. The projections include rounded edges and are arranged in a high density pattern. The deflector is coated with a thermal barrier coating and a bondcoat to minimize exposure to hot combustion gases or flame radiation.

Abstract: A process of forming a ceramic coating on a component. The process generally entails placing the component in a coating chamber containing oxygen and an inert gas, heating a surface of the component to a temperature of about 100 to about 150° C., and then generating a metal vapor from at least one metal target using a microwave-stimulated, oxygen-containing sputtering technique. The metal vapor is then caused to condense on the component surface to form a metal layer, after which the metal layer is treated with a microwave-stimulated plasma to oxidize the metal layer and form an oxide layer having a columnar microstructure. The generating, condensing and treating steps can be repeated any number of times to form multiple oxide layers that together constitute the ceramic coating.

Abstract: A method of depositing by chemical vapor deposition a modified platinum aluminide diffusion coating onto a superalloy substrate comprising the steps of applying a layer of a platinum group metal to the superalloy substrate; passing an externally generated aluminum halide gas through an internal gas generator which is integral with a retort, the internal gas generator generating a modified halide gas; and co-depositing aluminum and modifier onto the superalloy substrate. In one form, the modified halide gas is hafnium chloride and the modifier is hafnium with the modified platinum aluminum bond coat comprising a single phase additive layer of platinum aluminide with at least about 0.5 percent hafnium by weight percent and about 1 to about 15 weight percent of hafnium in the boundary between a diffusion layer and the additive layer. The bond coat produced by this method is also claimed.

Abstract: A combustor for a gas turbine engine includes a deflector assembly that enhances heat transfer from the combustor and minimizes low cycle fatigue stresses induced within the combustor. The deflector assembly includes a plurality of deflectors secured to a spectacle plate. Each deflector has tapered edges and includes a plurality of cylindrical projections extending outward from the deflector to facilitate heat transfer. The projections include rounded edges and are arranged in a high density pattern. The deflector is coated with a thermal barrier coating and a bondcoat to minimize exposure to hot combustion gases or flame radiation.

Abstract: Improved adhesion of thermal barrier coatings to nonmetallic substrates using a dense layer of ceramic on an underlying nonmetallic substrate that includes at least one oxidizable component. The improved adhesion occurs because the application of the dense ceramic layer forms a diffusion barrier for oxygen. This diffusion barrier prevents the oxidizable component of the substrate from decomposing. The present invention applies ceramic by a process that deposits a relatively thick and dense ceramic layer on the underlying substrate. The formation of the dense layer of ceramic avoids the problem of void formation associated with ceramic formation by most prior art thermal decomposition processes. The formation of voids has been associated with premature spalling of thermal barrier layers and other protective layers applied to substrates.

Abstract: 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.

Abstract: A tightly adherent anti-stick coating applied over coated turbine components of gas turbine engines. The tightly adherent coating is an oxide of at least one metal selected from the group consisting of Pt, W, group 4b and group 5b metals of the periodic table and Si, Ge and Sn of group 4a. The oxide is applied directly over existing environmental coatings, and thermal barrier coatings. It can also be applied directly to substrate material and to areas that are not within the combustion exhaust gases, such as platform portions and shank portions of airfoils including turbine blades. The oxide is conveniently applied to a uniform thickness of no greater than about 10 microns, and prevents the build-up of corrosion products and other products of combustion from the gases, thereby increasing the life expectancy of the component.

Abstract: A coating system for Si-containing material, such as those used to form articles exposed to high temperatures, including the hostile thermal environment of a gas turbine engine. The coating system is a compositionally-graded thermal/environmental barrier coating (T/EBC) system that exhibits improved mechanical integrity for high application temperatures that necessitate thick protective coatings. The T/EBC system includes an intermediate layer containing YSZ and BSAS, mullite and/or alumina, which is preferably used in combination with a mullite-containing layer that overlies the surface of the Si-containing material, a layer of BSAS between the mullite-containing layer and the intermediate layer, and a thermal-insulating top coat of YSZ overlying the intermediate layer.

Abstract: A tightly adherent anti-stick coating applied over coated turbine components of gas turbine engines. The tightly adherent coating is an oxide of at least one metal selected from the group consisting of Pt, W, group 4b and group 5b metals of the periodic table and Si, Ge and Sn of group 4a. The oxide is applied directly over existing environmental coatings, and thermal barrier coatings. It can also be applied directly to substrate material and to areas that are not within the combustion exhaust gases, such as platform portions and shank portions of airfoils including turbine blades. The oxide is conveniently applied to a uniform thickness of no greater than about 10 microns, and prevents the build-up of corrosion products and other products of combustion from the gases, thereby increasing the life expectancy of the component.