Abstract: An apparatus for depositing a ceramic coating on a component. The apparatus is configured to make use of an evaporation source containing multiple different oxide compounds, in which at least one of the oxide compounds has a vapor pressure that is higher than the remaining oxide compounds. The apparatus is operable to introduce the evaporation source into a coating chamber, suspend the component near the evaporation source, and project a high-energy beam on the evaporation source to melt and form a vapor cloud having a composition comprising the oxide compounds of the evaporation source. The apparatus includes a feature that prevents the vapor cloud from contacting and condensing on the component during an initial phase of operation, and subsequently permit and then again prevent the vapor cloud from contacting and condensing on the component during subsequent phases of operation in response to changes in the composition of the vapor cloud.

Abstract: A coating and process for depositing the coating on a substrate. The coating is a nickel aluminide overlay coating of predominantly the beta (NiAl) and gamma-prime (Ni3Al) intermetallic phases, and is suitable for use as an environmental coating and as a bond coat for a thermal barrier coating (TBC). The coating can be formed by depositing nickel and aluminum in appropriate amounts to yield the desired beta+gamma prime phase content. Alternatively, nickel and aluminum can be deposited so that the aluminum content of the coating exceeds the appropriate amount to yield the desired beta+gamma prime phase content, after which the coating is heat treated to diffuse the excess aluminum from the coating into the substrate to yield the desired beta+gamma prime phase content.

Abstract: A coating process and system suitable for use on components subjected to high temperatures. The coating system includes an overlay coating of predominantly B2 phase rhodium aluminide (RhAl) intermetallic compound containing about 25 to about 90 atomic percent rhodium, about 10 to about 60 atomic percent aluminum, optionally up to a combined total of about 25 atomic percent of one or more platinum group metals chosen from the group consisting of platinum, palladium, ruthenium, and iridium, and up to about 20 atomic percent of the base metal and alloying constituents of the substrate. The RhAl intermetallic coating may serve as an environmental coating, a diffusion barrier layer for an overlying environmental coating, or both, with or without an outer ceramic coating.

Abstract: A process and apparatus for depositing a ceramic coating, such as a thermal barrier coating (TBC) for a gas turbine engine component. The process deposits a coating whose composition includes multiple oxide compounds and a carbon-based constituent, e.g., elemental carbon, carbides, and carbon-based gases. The process uses at least one evaporation source to provide multiple different oxide compounds and at least one carbide compound comprising carbon and an element. The evaporation source is evaporated to produce a vapor cloud that contacts and condenses on the component surface to form the ceramic coating, and particularly so that the coating comprises the oxide compounds, an oxide of the element of the carbide compound, and the carbide compound and/or a carbon-containing gas. The process is carried out with an apparatus comprising a coating chamber in which the evaporation source is present, and a device for evaporating the evaporation source.

Abstract: A coating process for an article having a substrate formed of a metal alloy that is prone to the formation of a secondary reaction zone (SRZ). The coating process forms a coating system that includes an aluminum-containing overlay coating and a stabilizing layer between the overlay coating and the substrate. The overlay coating contains aluminum in an amount greater by atomic percent than the metal alloy of the substrate, such that there is a tendency for aluminum to diffuse from the overlay coating into the substrate. The stabilizing layer is predominantly or entirely formed of at least one platinum group metal (PGM), namely, platinum, rhodium, iridium, and/or palladium. The stabilizing layer is sufficient to inhibit diffusion of aluminum from the overlay coating into the substrate so that the substrate remains essentially free of an SRZ that would be deleterious to the mechanical properties of the alloy.

Abstract: A method for joining a plurality of single crystal members includes providing a bonding foil with a composition match with that of the members and with a bonding temperature within the gamma prime solution temperature range of the members, but below the melting temperature of the foil and below the incipient melting temperature of the members. The foil is disposed between and in contact with opposing members to be joined while heated to and held at the bonding temperature for at least 10 hours.

Abstract: Thermal barrier coating systems for use with hot section components of a gas turbine engine include an inner layer overlying a bond coated substrate and a top layer overlying at least a portion of the inner layer. The inner layer includes a thermal barrier material such as yttria-stabilized zirconia. The top layer includes a rare earth aluminate. The thicknesses and microstructures of the layers may be varied depending on the type of component to be coated. Articles incorporating the thermal barrier coating system exhibit improved resistance to CMAS infiltration.

Abstract: Nb—Si based alloy articles comprising a Nb—Si based alloy upon which is disposed an environmentally-resistant coating are described. They include a coating comprising at least one phase selected from the group consisting of M(Al,Si)3, M5(Al,Si)3, and M3Si5Al2, wherein M is one or more of Nb, Ti, Hf, Cr. Such coating can improve the environmental (e.g., in oxidation-promoting environments) resistance of a Nb—Si based alloy and alloy articles. Methods for preparing these articles are described as well.

Abstract: A coating system and coating method for damping vibration in an airfoil of a rotating component of a turbomachine. The coating system includes a metallic coating on a surface of the airfoil, and a ceramic coating overlying the metallic coating. The metallic coating contains metallic particles dispersed in a matrix having a metallic and/or intermetallic composition. The metallic particles are more ductile than the matrix, and have a composition containing silver and optionally tin. The method involves ion plasma cleaning the surface of the airfoil before depositing the metallic coating and then the ceramic coating.

Abstract: A coating and process for depositing the coating on a substrate. The coating is a nickel aluminide overlay coating of predominantly the beta (NiAl) and gamma-prime (Ni3Al) intermetallic phases, and is suitable for use as an environmental coating and as a bond coat for a thermal barrier coating (TBC). The coating can be formed by depositing nickel and aluminum in appropriate amounts to yield the desired beta+gamma prime phase content. Alternatively, nickel and aluminum can be deposited so that the aluminum content of the coating exceeds the appropriate amount to yield the desired beta+gamma prime phase content, after which the coating is heat treated to diffuse the excess aluminum from the coating into the substrate to yield the desired beta+gamma prime phase content.

Abstract: A process and apparatus for depositing a ceramic coating, such as a thermal barrier coating (TBC) for a gas turbine engine component. The process deposits a coating whose composition includes multiple oxide compounds and a carbon-based constituent, e.g., elemental carbon, carbides, and carbon-based gases. The process uses at least one evaporation source to provide multiple different oxide compounds and at least one carbide compound comprising carbon and an element. The evaporation source is evaporated to produce a vapor cloud that contacts and condenses on the component surface to form the ceramic coating, and particularly so that the coating comprises the oxide compounds, an oxide of the element of the carbide compound, and the carbide compound and/or a carbon-containing gas. The process is carried out with an apparatus comprising a coating chamber in which the evaporation source is present, and a device for evaporating the evaporation source.

Abstract: A gas turbine engine component and coating system including a superalloy substrate having a coating system disposed thereon. A bond coating may be applied to the substrate. An adherent layer of ceramic material forming a thermal barrier coating is present on the bond coat layer. A topcoat layer overlies the thermal barrier coating. The topcoat layer includes greater than about 20 wt % yttria.

Abstract: A protected article is prepared by providing the article, depositing a bond coat onto an exposed surface of the article, and producing a thermal barrier coating on an exposed surface of the bond coat. The step of producing the thermal barrier coating includes the steps of depositing a primary ceramic coating onto an exposed surface of the bond coat, and depositing a stabilization composition onto an exposed surface of the primary ceramic coating. The stabilization composition includes a first element selected from Group 2 or Group 3 of the periodic table, and a second element selected from Group 5 of the periodic table. The atomic ratio of the amount of the first element to the amount of the second element is at least 1.3, more preferably at least 1:1.

Abstract: A process and apparatus for depositing a ceramic coating, such as a thermal barrier coating (TBC) for a gas turbine engine component. The process deposits a coating whose composition includes multiple oxide compounds and a carbon-based constituent, e.g., elemental carbon, carbides, and carbon-based gases. The process uses at least one evaporation source to provide multiple different oxide compounds and at least one carbide compound comprising carbon and an element. The evaporation source is evaporated to produce a vapor cloud that contacts and condenses on the component surface to form the ceramic coating, and particularly so that the coating comprises the oxide compounds, an oxide of the element of the carbide compound, and the carbide compound and/or a carbon-containing gas. The process is carried out with an apparatus comprising a coating chamber in which the evaporation source is present, and a device for evaporating the evaporation source.

Abstract: A coating system and coating method for damping vibration in an airfoil of a rotating component of a turbomachine. The coating system includes a metallic coating on a surface of the airfoil, and a ceramic coating overlying the metallic coating. The metallic coating contains metallic particles dispersed in a matrix having a metallic and/or intermetallic composition. The metallic particles are more ductile than the matrix, and have a composition containing silver and optionally tin. The method involves ion plasma cleaning the surface of the airfoil before depositing the metallic coating and then the ceramic coating.

Abstract: A diffusion barrier coating includes, in an exemplary embodiment, a composition selected from the group consisting of a solid-solution alloy comprising rhenium and ruthenium wherein the ruthenium comprises about 50 atom % or less of the composition and where a total amount of rhenium and ruthenium is greater than 70 atom %; an intermetallic compound including at least one of Ru(TaAl) and Ru2TaAl, where Ru(TaAl) has a B2 structure and Ru2TaAl has a Heusler structure; and an oxide dispersed in a metallic matrix wherein greater than about 50 volume percent of the matrix comprises the oxide.

Abstract: A coating process for an article having a substrate formed of a metal alloy that is prone to the formation of a secondary reaction zone (SRZ). The coating process forms a coating system that includes an aluminum-containing overlay coating and a stabilizing layer between the overlay coating and the substrate. The overlay coating contains aluminum in an amount greater by atomic percent than the metal alloy of the substrate, such that there is a tendency for aluminum to diffuse from the overlay coating into the substrate. The stabilizing layer is predominantly or entirely formed of at least one platinum group metal (PGM), namely, platinum, rhodium, iridium, and/or palladium. The stabilizing layer is sufficient to inhibit diffusion of aluminum from the overlay coating into the substrate so that the substrate remains essentially free of an SRZ that would be deleterious to the mechanical properties of the alloy.

Abstract: Methods for providing improved resistance to CMAS infiltration for hot section components of a gas turbine engine. Exemplary methods include coating a substrate with a thermal barrier coating system by overlying a bond coated substrate with an inner thermal barrier layer comprised of a thermal barrier material such as yttria-stabilized zirconia. A top layer, including a rare-earth aluminate, is deposited so as to overlie at least a portion of the inner layer. Deposition processes and coating thicknesses may be tailored to the type of component to be coated.

Abstract: Thermal barrier coating systems for use with hot section components of a gas turbine engine include an inner layer overlying a bond coated substrate and a top layer overlying at least a portion of the inner layer. The inner layer includes a thermal barrier material such as yttria-stabilized zirconia. The top layer includes a rare earth aluminate. The thicknesses and microstructures of the layers may be varied depending on the type of component to be coated.

Abstract: A coating process and system for an article having a substrate formed of a metal alloy that is prone to the formation of a secondary reaction zone (SRZ). The coating system includes an aluminum-containing overlay coating and a stabilizing layer between the overlay coating and the substrate. The overlay coating contains aluminum in an amount greater by atomic percent than the metal alloy of the substrate, such that there is a tendency for aluminum to diffuse from the overlay coating into the substrate. The stabilizing layer is predominantly or entirely formed of at least one platinum group metal (PGM), namely, platinum, rhodium, iridium, and/or palladium. The stabilizing layer is sufficient to inhibit diffusion of aluminum from the overlay coating into the substrate so that the substrate remains essentially free of an SRZ that would be deleterious to the mechanical properties of the alloy.