Abstract: Coating systems for a turbine blade tip, such as a metal turbine blade tip, are provided. The coating system can include a thermal barrier coating on the surface of the turbine blade tip as well as one or more bond coats and/or metallic coatings. The coated blade tip can be used with a ceramic matrix composite shroud coated with an environmental barrier coating to reduce blade tip wear. Methods are also provided for applying the coating system onto a turbine blade tip.

Abstract: A turbine system including a sealing component is presented. The sealing component is positioned in a gap between adjacent turbine components of the turbine system. The sealing component includes a metallic shim including a high-temperature-resistant alloy in a single crystal form. A turbine shroud assembly including the sealing component is also presented.

Abstract: Articles having coatings that are resistant to high temperature degradation are described, along with methods for making such articles. The article comprises a coating disposed on a substrate. The coating comprises a plurality of elongated surface-connected voids. The article further includes a protective agent disposed within at least some of the voids of the coating; the protective agent comprises a substance capable of chemically reacting with liquid nominal CMAS to form a solid crystalline product outside the crystallization field of said nominal CMAS. This solid crystalline product has a melting temperature greater than about 1200 degrees Celsius. The method generally includes disposing the protective agent noted above within the surface connected voids of the coating at an effective concentration to substantially prevent incursion of CMAS materials into the voids in which the protective agent is disposed.

Abstract: An article having a damage-tolerant thermal barrier coating includes a plurality of coating layers disposed over a substrate. The plurality of coatings comprises an inner layer and an outer layer. The outer layer is more resistant to infiltration by nominal CMAS relative to 8 weight percent yttria-stabilized zirconia at a temperature of 1300 degrees Celsius. The inner layer has, in a temperature range from about 1000 degrees Celsius to about 1200 degrees Celsius, a thermal resistance in a range from about 9×10?5 degree Kelvin per watt to about 23×10?5 degree Kelvin per watt.

Abstract: A method for coating a surface of a substrate is provided. The method includes providing a suspension or a precursor comprising feedstock material suspended in a liquid medium. Further, the method includes spraying the suspension or the precursor onto the surface at a spray angle less than about 75 degrees to a tangent of the surface.

Abstract: A coating comprising a first surface and a second surface is provided. The coating includes a plurality of growth domains. An orientation of at least one growth domain of the plurality of growth domains is non-vertical with respect to the first surface of the coating. One or more growth domains of the plurality of growth domains comprise a plurality of at least partially melted and solidified particles.

Abstract: Article includes a substrate, a bond coat disposed on the substrate, an environmental barrier coating disposed on the bond coat, and a patterned abradable coating disposed on the second top coat. The environmental barrier coating includes an intermediate layer disposed on the bond coat, a sealing layer disposed on the intermediate layer, a first top coat disposed on the sealing layer, and a second top coat disposed on the first top coat. The first top coat is different from the second top coat.

Abstract: Articles having coatings that are resistant to high temperature degradation are described, along with methods for making such articles. The article comprises a coating disposed on a substrate. The coating comprises a plurality of elongated surface-connected voids. The article further includes a protective agent disposed within at least some of the voids of the coating; the protective agent comprises a substance capable of chemically reacting with liquid nominal CMAS to form a solid crystalline product outside the crystallization field of said nominal CMAS. This solid crystalline product has a melting temperature greater than about 1200 degrees Celsius. The method generally includes disposing the protective agent noted above within the surface connected voids of the coating at an effective concentration to substantially prevent incursion of CMAS materials into the voids in which the protective agent is disposed.

Abstract: An article for use in aggressive environments is presented. In one embodiment, the article comprises a substrate and a self-sealing and substantially hermetic sealing layer comprising an alkaline-earth aluminosilicate disposed over the bondcoat. The substrate may be any high-temperature material, including, for instance, silicon-bearing ceramics and ceramic matrix composites. A method for making such articles is also presented. The method comprises providing a substrate; disposing a self-sealing alkaline-earth aluminosilicate layer over the substrate; and heating the sealing layer to a sealing temperature at which at least a portion of the sealing layer will flow.

Abstract: An article and method of forming the article are disclosed. The article includes a substrate, an overlay bond coat deposited over the substrate and a topcoat deposited over the bond coat. The bond coat of the article includes a plasma affected region proximate to an interface between the bond coat and the topcoat, and the plasma affected region includes an elongated intergranular phase. The method of depositing includes adjusting the plasma spray conditions so as to form the plasma affected region proximate to an interface between the bond coat and the topcoat, and elongated intergranular phases in the plasma affected regions.

Abstract: Articles suitable for use as high-temperature machine components include a substrate and an environmental barrier coating disposed over the substrate, where the environmental barrier coating includes at least one hermetic self-sealing layer formed from a mixture including an alkaline earth metal aluminosilicate and a rare-earth silicate, and where the at least one hermetic self-sealing layer exhibits substantially no net remnant or residual expansion when subjected to high temperature heat treatment. The environmental barrier coating can further include a bondcoat disposed between the substrate and the hermetic self-sealing layer, a topcoat disposed over the hermetic self-sealing layer, and/or an intermediate layer disposed between the hermetic self-sealing layer and the bondcoat. The intermediate layer can include a barrier material that is substantially inert with respect to silica.

Abstract: The present application provides Calcia-Magnesia-Alumina-Silica (CMAS) (or molten silicate) resistant thermal barrier coatings (TBC). The coatings include elongate growth domains of non-equiaxed, randomly arranged overlapping grains or splats. The elongate growth domains include overlapping individual, randomly distributed splats of tough and soft phases. In some embodiments, the elongate growth domains are formed via air plasma spray. In some embodiments, the tough phases are at least partially stabilized zirconia and/or hafnia compositions, and the soft phases are CMAS (or molten silicate) reactive or resistant compositions. Within each elongate growth domain, the mixture of the tough and soft phases act together to limit penetration of CMAS and also provide sufficient domain toughness to minimize cracking forces produced during crystallization of infiltrated CMAS.

Abstract: Articles for high temperature service, especially where enhanced strain tolerance coupled with resistance to ingested dust and debris (CMAS) is desirable, are provided herein. The article comprises a substrate and a multi-layered coating system disposed over the substrate. The coating system comprises a first layer comprising a first material and a second layer comprising a second material, with the first layer disposed between the second layer and the substrate. The second material is more resistant to infiltration by a nominal CMAS composition relative to 8 weight percent yttria-stabilized zirconia at a temperature of 1300 degrees Celsius. The second layer comprises a plurality of through-thickness cracks, wherein at least 90 percent of the cracks have a mean crack opening displacement, measured in a distal surface region, of up to about 5 micrometers.

Abstract: An article and method of forming the article are disclosed. The article includes a substrate, an overlay bond coat deposited over the substrate and a topcoat deposited over the bond coat. The bond coat of the article includes a plasma affected region proximate to an interface between the bond coat and the topcoat, and the plasma affected region includes an elongated intergranular phase. The method of depositing includes adjusting the plasma spray conditions so as to form the plasma affected region proximate to an interface between the bond coat and the topcoat, and elongated intergranular phases in the plasma affected regions.

Abstract: A method of forming an article includes forming a silicon-containing layer on a silicon-containing region of a surface of a substrate of the article; forming a plurality of channels and ridges in the silicon-containing layer; and forming at least one outer layer overlying the surface of the silicon-containing region. The plurality of channels and ridges may be formed by adding silicon-containing material to the silicon-containing layer. The channels and ridges may be formed by subtracting material from the silicon-containing layer. The channels and ridges may be formed by forming channels or grooves in the silicon-containing region of the surface of the substrate prior to formation of the silicon-containing layer.

Abstract: A coating comprising a first surface and a second surface is provided. The coating includes a plurality of growth domains. An orientation of at least one growth domain of the plurality of growth domains is non-vertical with respect to the first surface of the coating. One or more growth domains of the plurality of growth domains comprise a plurality of at least partially melted and solidified particles.

Abstract: Coatings and articles suitable for use in high temperature environments, for example, are presented. One embodiment is a coating that comprises a plurality of elongate material growth domains defined between domain boundaries. The domains have an intra-domain density of at least about 75% of theoretical density, have a substantially equiaxed grain morphology, and comprise a plurality of at least partially melted and solidified particles. Another embodiment is a coating that comprises a matrix comprising a substantially equiaxed grain morphology and a plurality of vertically oriented cracks disposed in the matrix. Further embodiments include articles comprising one or more of the coatings described above.

Abstract: Coatings and articles suitable for use in high temperature environments, for example, are presented. One embodiment is a coating that comprises a plurality of elongate material growth domains defined between domain boundaries. The domains have an intra-domain density of at least about 75% of theoretical density, have a substantially equiaxed grain morphology, and comprise a plurality of at least partially melted and solidified particles. Another embodiment is a coating that comprises a matrix comprising a substantially equiaxed grain morphology and a plurality of vertically oriented cracks disposed in the matrix. Further embodiments include articles comprising one or more of the coatings described above.

Abstract: Articles coated via a plasma spray process, and methods for making such articles, are presented. For example, one embodiment is an article comprising a substrate comprising a top surface and a channel disposed in the substrate. The channel is defined by an internal channel surface disposed beneath the top surface and having a terminal end at an orifice at the top surface. A coating is disposed on the top surface and on at least a portion of the internal channel surface. A coating thickness at any point on the internal channel surface is less than a nominal coating thickness on the top surface, and the coating comprises a plurality of at least partially melted and solidified particles.

Abstract: Articles coated via a plasma spray process, and methods for making such articles, are presented. For example, one embodiment is an article comprising a substrate comprising a top surface and a channel disposed in the substrate. The channel is defined by an internal channel surface disposed beneath the top surface and having a terminal end at an orifice at the top surface. A coating is disposed on the top surface and on at least a portion of the internal channel surface. A coating thickness at any point on the internal channel surface is less than a nominal coating thickness on the top surface, and the coating comprises a plurality of at least partially melted and solidified particles.