A method of making a multilayer environmental barrier coating for a ceramic matrix composite is provided, comprising the steps of: plasma spray coating an oxide-based bond coat over top of the ceramic matrix composite and depositing a columnar top coat over the oxide-based bond coat.

A method for coating a substrate includes spraying a combination of powders. The combination of powders includes: Hf.sub.0.5Si.sub.0.5O.sub.2; Zr.sub.0.5Si.sub.0.5O.sub.2; and, optionally, at least one of HfO.sub.2 and ZrO.sub.2. A molar ratio of said Hf.sub.0.5Si.sub.0.5O.sub.2 and HfO.sub.2 combined to said Zr.sub.0.5Si.sub.0.5O.sub.2 and ZrO.sub.2 combined is from 2:1 to 4:1. A molar ratio of said Hf.sub.0.5Si.sub.0.5O.sub.2 to said HfO.sub.2 is at least 1:3.

A method for coating a substrate includes spraying a combination of powders. The combination of powders includes: Hf.sub.0.5Si.sub.0.5O.sub.2; Zr.sub.0.5Si.sub.0.5O.sub.2; and, optionally, at least one of HfO.sub.2 and ZrO.sub.2. A molar ratio of said Hf.sub.0.5Si.sub.0.5O.sub.2 and HfO.sub.2 combined to said Zr.sub.0.5Si.sub.0.5O.sub.2 and ZrO.sub.2 combined is from 2:1 to 4:1. A molar ratio of said Hf.sub.0.5Si.sub.0.5O.sub.2 to said HfO.sub.2 is at least 1:3.

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.

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.

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.

An environmental barrier coating includes a barrier layer which includes a matrix, diffusive particles, and gettering particles; and a calcium-magnesia alumina-silicate (CMAS)-resistant component. The CMAS-resistant component includes hafnium silicate and a rare earth hafnate. An article and a method of fabricating an article are also disclosed.

An environmental barrier coating includes a barrier layer which includes a matrix, diffusive particles, and gettering particles; and a calcium-magnesia alumina-silicate (CMAS)-resistant component. The CMAS-resistant component includes hafnium silicate and a rare earth hafnate. An article and a method of fabricating an article are also disclosed.

An environmental barrier coating includes a barrier layer which includes a matrix, diffusive particles, and gettering particles; and a calcium-magnesia alumina-silicate (CMAS)-resistant component. The CMAS-resistant component includes hafnium silicate and a rare earth hafnate. An article and a method of fabricating an article are also disclosed.