An airfoil includes an airfoil wall that defines a leading end, a trailing end, and suction and pressure sides that join the leading end and the trailing end. The airfoil wall is formed of a silicon-containing ceramic. A first environmental barrier topcoat is disposed on the suction side of the airfoil wall, and a second, different environmental barrier topcoat is disposed on the pressure side of the airfoil wall. The first topcoat is vaporization-resistant and the second topcoat is resistant to calcium-magnesium-aluminosilicate.

An airfoil includes an airfoil wall that defines a leading end, a trailing end, and suction and pressure sides that join the leading end and the trailing end. The airfoil wall is formed of a silicon-containing ceramic. A first environmental barrier topcoat is disposed on the suction side of the airfoil wall, and a second, different environmental barrier topcoat is disposed on the pressure side of the airfoil wall. The first topcoat is vaporization-resistant and the second topcoat is resistant to calcium-magnesium-aluminosilicate.

Methods for preparing an environmental barrier coating and the resulting coating are provided. The methods and products include the incorporation of a continuous ceramic inner layer and a segmented ceramic outer layer on a CMC component. The segmented ceramic outer layer may be formed by thermal spray techniques. The coating is more stable at higher temperatures and provides for a longer lifetime of the coated component.

Methods for preparing an environmental barrier coating and the resulting coating are provided. The methods and products include the incorporation of a continuous ceramic inner layer and a segmented ceramic outer layer on a CMC component. The segmented ceramic outer layer may be formed by thermal spray techniques. The coating is more stable at higher temperatures and provides for a longer lifetime of the coated component.

A method of forming a barrier layer on a ceramic matrix composite (CMC) is described. The method includes forming a particulate surface layer comprising silicon particles on an outer surface of a fiber preform. The particulate surface layer is nitrided to convert the silicon particles to silicon nitride particles. After the nitriding, the fiber preform and the particulate surface layer are infiltrated with a molten material comprising silicon. Following infiltration, the molten material is cooled, thereby forming a ceramic matrix composite with a barrier layer thereon, where the barrier layer comprises silicon nitride and less than 5 vol. % free silicon. The barrier layer may also include silicon carbide and/or one or more refractory metal silicides.

A method of forming a barrier layer on a ceramic matrix composite (CMC) is described. The method includes forming a particulate surface layer comprising silicon particles on an outer surface of a fiber preform. The particulate surface layer is nitrided to convert the silicon particles to silicon nitride particles. After the nitriding, the fiber preform and the particulate surface layer are infiltrated with a molten material comprising silicon. Following infiltration, the molten material is cooled, thereby forming a ceramic matrix composite with a barrier layer thereon, where the barrier layer comprises silicon nitride and less than 5 vol. % free silicon. The barrier layer may also include silicon carbide and/or one or more refractory metal silicides.

A method of applying a coating to a substrate includes forming a slurry by mixing elemental precursors of gettering particles, diffusive particles, matrix material, and a carrier fluid; applying the slurry to a substrate; and sintering the slurry to form a composite material. The sintering causes the elemental precursors to react with one another to form gettering particles. An article is also disclosed.

An article for use in a high-temperature environment that includes a substrate including a superalloy material, a ceramic, or a ceramic matrix composite, and an abradable coating on the substrate, the abradable coating including a rare earth silicate and a dislocator phase, the dislocator phase forms one or more distinct phase regions in the abradable coating and comprises at least one of hafnium diboride (HfB.sub.2), zirconium diboride (ZrB.sub.2), tantalum nitride (TaN or Ta.sub.2N), tantalum carbide (Ta.sub.2C), titanium diboride (TiB.sub.2), zirconium carbide (ZrC), hafnium carbide (HfC), tantalum diboride (TaB.sub.2), hafnium nitride (HfN), or niobium carbide (NbC).

An article for use in a high-temperature environment that includes a substrate including a superalloy material, a ceramic, or a ceramic matrix composite, and an abradable coating on the substrate, the abradable coating including a rare earth silicate and a dislocator phase, the dislocator phase forms one or more distinct phase regions in the abradable coating and comprises at least one of hafnium diboride (HfB.sub.2), zirconium diboride (ZrB.sub.2), tantalum nitride (TaN or Ta.sub.2N), tantalum carbide (Ta.sub.2C), titanium diboride (TiB.sub.2), zirconium carbide (ZrC), hafnium carbide (HfC), tantalum diboride (TaB.sub.2), hafnium nitride (HfN), or niobium carbide (NbC).

Methods for preparing an environmental barrier coating and the resulting coating are provided. The methods and products include the incorporation of a continuous ceramic inner layer and a segmented ceramic outer layer on a CMC component. The segmented ceramic outer layer may be formed by thermal spray techniques. The coating is more stable at higher temperatures and provides for a longer lifetime of the coated component.