The disclosure describes articles and techniques that include an airfoil having a hybrid coating system to provide improved particle impact resistance and improve CMAS attack resistance on the pressure side of the airfoil and improved thermal load protection on the suction side of the airfoil. An example article for a gas turbine engine may include a substrate, and a hybrid environmental barrier coating (EBC) including a relatively dense EBC layer on a first portion of the substrate and a relatively porous EBC layer on a second portion of the substrate, where the first portion of the substrate is different from the second portion of the substrate, and wherein at least a portion of the relatively porous EBC layer overlaps at least a portion of the relatively dense EBC layer in an overlap region.

A method for manufacturing an environmental barrier comprising the steps of coating a rare earth silicate powder with a precursor of a densification agent in order to form a rare earth silicate powder coated with the precursor of the densification agent, thermally spraying the coated powder onto a substrate in order to obtain an at least partially amorphous environmental barrier on the substrate and thermally treating the environmental barrier in order to crystallize and densify the environmental barrier.

A method for manufacturing an environmental barrier comprising the steps of coating a rare earth silicate powder with a precursor of a densification agent in order to form a rare earth silicate powder coated with the precursor of the densification agent, thermally spraying the coated powder onto a substrate in order to obtain an at least partially amorphous environmental barrier on the substrate and thermally treating the environmental barrier in order to crystallize and densify the environmental barrier.

A part includes a substrate, having, adjacent to a surface of the substrate, at least a portion that is made from a material that contains silicon, and an environmental barrier formed on the surface of the substrate, the environmental barrier including at least a first layer including a rare earth disilicate of formula RE.sup.a.sub.2Si.sub.2O.sub.7 present at a molar content lying in the range 70% to 99.9%, where RE.sup.a is a rare earth element; and at least one rare earth oxide of formula RE.sup.b.sub.2O.sub.3 present at a molar content lying in the range 0.1% to 30%, where RE.sup.b is a rare earth element different from RE.sup.a.

A part includes a substrate, having, adjacent to a surface of the substrate, at least a portion that is made from a material that contains silicon, and an environmental barrier formed on the surface of the substrate, the environmental barrier including at least a first layer including a rare earth disilicate of formula RE.sup.a.sub.2Si.sub.2O.sub.7 present at a molar content lying in the range 70% to 99.9%, where RE.sup.a is a rare earth element; and at least one rare earth oxide of formula RE.sup.b.sub.2O.sub.3 present at a molar content lying in the range 0.1% to 30%, where RE.sup.b is a rare earth element different from RE.sup.a.

Disclosed is a multi-phase abradable coating including a ceramic matrix and a dislocator phase.

Disclosed is a multi-phase abradable coating including a ceramic matrix and a dislocator phase.

A method of protecting a gas turbine component for operation in a high temperature environment that includes the gas turbine component including a substrate having a silicon-containing layer, wherein the gas turbine component has a curved surface; forming a flexible mask configured to cover the curved surface of the gas turbine component, the flexible mask including a plurality of slots disposed in a pattern; disposing the flexible mask in direct contact with the curved surface of the gas turbine component; applying a bondcoat onto the flexible mask and the gas turbine component, such that bondcoat fills the plurality of slots and contacts the curved surface; and removing the flexible mask by heat or chemical reaction, such that, after removing the flexible mask, the curved surface of the gas turbine component comprises a patterned bondcoat layer in the pattern defined by the flexible mask.

A method of protecting a gas turbine component for operation in a high temperature environment that includes the gas turbine component including a substrate having a silicon-containing layer, wherein the gas turbine component has a curved surface; forming a flexible mask configured to cover the curved surface of the gas turbine component, the flexible mask including a plurality of slots disposed in a pattern; disposing the flexible mask in direct contact with the curved surface of the gas turbine component; applying a bondcoat onto the flexible mask and the gas turbine component, such that bondcoat fills the plurality of slots and contacts the curved surface; and removing the flexible mask by heat or chemical reaction, such that, after removing the flexible mask, the curved surface of the gas turbine component comprises a patterned bondcoat layer in the pattern defined by the flexible mask.

In one example, a method for forming a coating system including a bond coat and an environmental barrier coating on a ceramic or CMC substrate, e.g., with an abradable coating on the environmental barrier coating. The method may include depositing a bond coat on a ceramic or ceramic matrix composite (CMC) substrate to form an as-deposited bond coat; heat treating the as-deposited bond coat following the deposition of the as-deposited bond coat on the substrate to form a heat treated bond coat; depositing an environment barrier coating (EBC) layer on the heat treated bond coat to form as deposited EBC layer; and heat treating the as-deposited EBC layer to form a heat treated EBC layer.