Abstract: A compound is generally provided that has the formula: Ln3-xBxM5-yByO12, where Ln comprises Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, or a mixture thereof; x is 0 to about 1.5; M comprises Ga, In, Al, Fe, or a combination thereof; y is 0 to about 2.5; and x+y is greater than 0. A composition is also provided that includes a silicon-containing material (e.g., silicon metal and/or a silicide) and the boron-doped refractory compound having the formula described above, such as about 0.001% to about 85% by volume of the boron-doped refractory compound.

Abstract: A coated component, along with methods of its formation and use, is provided. The coated component may include a substrate having a surface with a plurality of cavities defined therein, a bond coating (e.g., including a silicon material) on the surface of the substrate within the cavities, and an environmental barrier coating over the surface of the substrate and encasing the bond coating within the cavities such that the bond coating, when melted, is contained within the cavities. Such a coated component may be, in one embodiment, a turbine component, such as a CMC component for use in a hot gas path of a gas turbine engine.

Abstract: A coated component, along with method of forming the same, is provided. The coated component may include a substrate having a surface, a silicon-based bond coating on the surface of the substrate, and an EBC on the silicon-based bond coating. The silicon-based bond coating may include a silicon-phase contained within a refractory phase. The silicon-phase, when melted, is contained within the refractory phase and between the surface of the substrate and an inner surface of the environmental barrier coating. Such a coated component may be, in particular embodiments, a turbine component.

Abstract: A coated component, along with methods of its formation and use, is provided. The coated component may include a substrate having a surface, a first refractory layer on the surface of the substrate, a silicon-based bond coating on the first refractory, and an environmental barrier coating on the silicon-based bond coating. The silicon-based bond coating includes a silicon-phase contained within a refractory phase such that, when melted, the silicon-phase is contained within the refractory phase and between the surface of the substrate and an inner surface of the environmental barrier coating.

Abstract: Compounds are generally provided, which may be particularly used to form a layer in a coating system. In one embodiment, the compound may have the formula: AxBbLn1-x-bHf1-t-dTitDdMO6, where: A is Al, Ga, In, Sc, Y, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Fe, Cr, Co, Mn, Bi, or a mixture thereof; x is about 0.01 to about 0.99; b is 0 to about 0.5, with 1-x-b being 0 to about 0.99 such that Ln is present in the compound; Ln is a rare earth or a mixture thereof that is different than A; t is 0 to about 0.99; D is Zr, Ce, Ge, Si, or a mixture thereof; d is 0 to about 0.5; the sum of t and d is less than 1 such that Hf is present in the compound; and M is Ta, Nb, or a mixture thereof.

Abstract: Coating systems are provided for positioning on a surface of a substrate, along with the resulting coated components and methods of their formation. The coating system may include a layer having a compound of the formula: A1?bBbZ1?dDdMO6 where: A is Al, Ga, In, Sc, Y, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Fe, Cr, Co, Mn, Bi, or a mixture thereof; b is 0 to about 0.5; Z is Hf, Ti, or a mixture thereof; D is Zr, Ce, Ge, Si, or a mixture thereof; d is 0 to about 0.5; and M is Ta, Nb, or a mixture thereof.

Abstract: A composition is provided that includes a silicon-containing material (e.g., a silicon metal and/or a silicide) and about 0.001% to about 85% of a Ga-containing compound, an In-containing compound, or a mixture thereof. The silicon-based layer can be a bond coating directly on the surface of the substrate. Alternatively or additionally, the silicon-based layer can be an outer layer defining a surface of the substrate, with an environmental barrier coating on the surface of the substrate. A coated component is also provided, as well as a method for coating a ceramic component. Gas turbine engines are also provided that include such a ceramic component.

Abstract: A composition is generally provided that includes a silicon-containing material (e.g., silicon metal and/or a silicide) and a boron-doped refractory compound, such as about 0.001% to about 85% by volume of the boron-doped refractory compound (e.g., about 1% to about 60% by volume). In one embodiment, a bond coating on a surface of a ceramic component is generally provided with the bond coating including such a composition, with the silicon-containing material is silicon metal.

Abstract: Methods for forming a hole in a coated component are provided. The method may include forming a sacrificial layer over a ceramic barrier coating of a substrate, drilling a hole into the coated component such that any spatter formed during drilling deposits onto the sacrificial layer, and removing the sacrificial layer along with the spatter deposited thereon. The sacrificial layer may include a rare earth oxide (e.g., rare earth oxide particles). Intermediate ceramic matrix composite (CMC) component are also provided. The intermediate CMC may include a CMC body, an environmental barrier coating on the bond coating, and a sacrificial layer on the environmental barrier coating, with the sacrificial layer including particles of a rare earth oxide dispersed in a polymeric matrix.

Abstract: Methods for forming a ceramic matrix composite (CMC) are generally provided. The method may include melt infiltrating a silicon mixture into a ceramic matrix composite preform, with the silicon mixture including SiGa, SiIn, or a mixture thereof. The silicon mixture may include silicon metal in combination with SiGa, SiIn, or the mixture thereof. Additionally, the silicon mixture may further include B within the SiGa, SiIn, or the mixture thereof (e.g., in the form of SiBGa, SiBIn, or a mixture thereof).

Abstract: A coated substrate is provided that includes an environmental barrier coating on (e.g., directly on) a surface of a substrate (e.g., a ceramic matrix composite). The environmental barrier coating can include a barrier layer having a refractory material phase and a silicon-containing glass phase. The silicon-containing glass phase may be a continuous phase within the barrier layer (e.g., a breathable grain boundary of the barrier layer), or may be a plurality of discontinuous layers dispersed throughout the refractory material phase. The refractory material phase can include a rare earth silicate material having a rare earth component at a first atomic percent, while the silicon-containing glass phase comprises the rare earth component at a second atomic percent that is less than the first atomic percent. Methods are also provided for forming a barrier layer on a substrate.

Abstract: Coating systems on a surface of a CMC component, such as a CMC shroud, are provided. The coating system can include an environmental barrier coating on the surface of the CMC component and an abradable coating on the environmental barrier coating and defining an external surface opposite of the environmental barrier coating. The abradable coating includes a compound having the formula: Ln2ABO8, where Ln comprises scandium, yttrium, lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, or mixtures thereof; A comprises Si, Ti, Ge, or a combination thereof; and B comprises Mo, W, or a combination thereof. In one embodiment, the abradable coating has a first coefficient of thermal expansion at an interface with the environmental barrier coating that changes to a second coefficient of thermal expansion at its external surface. Methods are also provided for applying an abradable coating onto a CMC component.

Abstract: A ceramic component is generally provided that includes a silicon-based layer comprising a silicon-containing material (e.g., a silicon metal and/or a silicide) and about 0.001% to about 85% of a Ga-containing compound. For example, the silicon-based layer can be a bond coating directly on the surface of the substrate. Alternatively or additionally, the silicon-based layer can be an outer layer defining a surface of the substrate, with an environmental barrier coating on the surface of the substrate. Gas turbine engines are also generally provided that include such a ceramic component.

Abstract: A coated seal slot system for turbomachinery includes a first turbine component comprising a first groove having at least one first coating attached to at least a portion of the first groove of the first turbine component, a second turbine component comprising a second groove having at least one second coating attached to at least a portion of the second groove of the second turbine component. The first and the second turbine components are disposable adjacent to each other with the first groove having the first coating and the second groove having the second coating together forming a coated seal slot extending across a gap between the first turbine component and the second turbine component. A seal is disposable in the coated seal slot and extendable across the gap between the first and the second turbine components and engageable with the first coating and the second coating to inhibit leakage of gas through the gap.

Abstract: Environmental barrier coatings for high temperature ceramic components including a bond coat layer; an optional silica layer; and at least one transition layer including: from about 85% to about 100% by volume of the transition layer of a primary transition material including a rare earth disilicate, or a doped rare earth disilicate; and from 0% to about 15% by volume of the transition layer of a secondary material selected from Fe2O3, iron silicates, rare earth iron oxides, Al2O3, mullite, rare earth aluminates, rare earth aluminosilicates, TiO2, rare earth titanates, Ga2O3, rare earth gallates, NiO, nickel silicates, rare earth nickel oxides, Lnb metals, Lnb2O3, Lnb2Si2O7, Lnb2SiO5, borosilicate glass, alkaline earth silicates, alkaline earth rare earth oxides, alkaline earth rare earth silicates, and mixtures thereof; where the transition layer is applied to the component as a slurry including at least an organic solvent, the primary transition material and at least one slurry sintering aid, and where a re

Abstract: A ceramic component is generally provided that includes a silicon-based layer comprising a silicon-containing material (e.g., a silicon metal and/or a silicide) and about 0.001% to about 85% of an In-containing compound. For example, the silicon-based layer can be a bond coating directly on the surface of the substrate. Alternatively or additionally, the silicon-based layer can be an outer layer defining a surface of the substrate, with an environmental barrier coating on the surface of the substrate. Gas turbine engines are also generally provided that include such a ceramic component.

Abstract: Methods for forming a ceramic matrix composite (CMC) are generally provided. The method may include melt infiltrating a silicon mixture into a ceramic matrix composite preform, with the silicon mixture including SiGa, SiIn, or a mixture thereof. The silicon mixture may include silicon metal in combination with SiGa, SiIn, or the mixture thereof. Additionally, the silicon mixture may further include B within the SiGa, SiIn, or the mixture thereof (e.g., in the form of SiBGa, SiBIn, or a mixture thereof).

Abstract: Methods for forming a ceramic matrix composite from a melt infiltrated and melt extracted preform that has residual silicon within open pore channels therein are provided. The method may include: introducing a carbon yielding resin into the open pore channels; heating the preform to produce elemental carbon from the carbon yielding resin within the open pore channels; and further heating the elemental carbon to react with the residual silicon to form SiC within the open pore channels to form the ceramic matrix composite.

Abstract: A coated substrate is provided that comprises: a substrate; and a barrier coating comprising a compound having the formula: Ln2ABOs, where Ln comprises scandium, yttrium, lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, or mixtures thereof; A comprises Si, Ti, Ge, Sn, Ce, Hf, Zr, or a combination thereof; and B comprises Mo, W, or a combination thereof. In one embodiment, B comprises Mo.

Abstract: Methods and materials for forming in-situ features in a ceramic matrix composite component are described. The method of forming a ceramic matrix composite component with cooling features, comprises forming a preform tape, laying up said preform tape to a desired shape, placing a high-temperature resistant fugitive material insert of preselected geometry in the preform tape of the desired shape, compacting the preform tape of the desired shape, burning out the preform tape of the desired shape, melt infiltrating the desired shape, removing the high-temperature resistant insert to form the cooling features during one of the burning out or the melt infiltrating or following the burning out or the melt infiltrating.