A blade outer air seal has at least one internal surface and a layer atop the at least one internal surface. The layer has: a matrix comprising at least one of hafnium silicate (HfSiO.sub.4) and zirconium silicate (ZrSiO.sub.4), ytterbium disilicate (Yb.sub.2Si.sub.2O.sub.7); and barium magnesium alumino silicate (BMAS) or other alkaline earth aluminosilicate.

A blade outer air seal has at least one internal surface and a layer atop the at least one internal surface. The layer has: a matrix comprising at least one of hafnium silicate (HfSiO.sub.4) and zirconium silicate (ZrSiO.sub.4), ytterbium disilicate (Yb.sub.2Si.sub.2O.sub.7); and barium magnesium alumino silicate (BMAS) or other alkaline earth 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 layer, 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 layer, 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.

The present application discloses a ceramic preform, a method of making a ceramic preform and a metal matrix composite comprising a ceramic preform. In one exemplary embodiment, the ceramic preform comprises a ceramic compound compressed into the shape of a cylinder by rotational compression molding. The cylinder has an inner surface and an outer surface. A first liner may be attached to the inner surface of the cylinder and a second liner may attached to the outer surface of the cylinder. The metal matrix composite of the present application may be formed as a brake drum or a brake disc.

The present application discloses a ceramic preform, a method of making a ceramic preform and a metal matrix composite comprising a ceramic preform. In one exemplary embodiment, the ceramic preform comprises a ceramic compound compressed into the shape of a cylinder by rotational compression molding. The cylinder has an inner surface and an outer surface. A first liner may be attached to the inner surface of the cylinder and a second liner may attached to the outer surface of the cylinder. The metal matrix composite of the present application may be formed as a brake drum or a brake disc.

A composite article comprises a substrate, the substrate comprising a silicon containing material and an additive comprising boron nitride nanotubes.

A composite article comprises a substrate, the substrate comprising a silicon containing material and an additive comprising boron nitride nanotubes.

An environmental barrier coating system for a turbine component, including an environmental barrier layer applied to a turbine component substrate containing silicon; the environmental barrier layer comprising an oxide matrix surrounding a fiber-reinforcement structure and a self-healing phase interspersed throughout the oxide matrix; wherein the fiber-reinforcement structure comprises at least one first fiber bundle oriented along a load bearing stress direction of said turbine component substrate; wherein the fiber-reinforcement structure comprises at least one second fiber bundle oriented orthogonal to the at least one first fiber bundle orientation; wherein the fiber-reinforcement structure comprises at least one third fiber woven between the at least one first fiber bundle and the at least one second fiber bundle.

An environmental barrier coating system for a turbine component, including an environmental barrier layer applied to a turbine component substrate containing silicon; the environmental barrier layer comprising an oxide matrix surrounding a fiber-reinforcement structure and a self-healing phase interspersed throughout the oxide matrix; wherein the fiber-reinforcement structure comprises at least one first fiber bundle oriented along a load bearing stress direction of said turbine component substrate; wherein the fiber-reinforcement structure comprises at least one second fiber bundle oriented orthogonal to the at least one first fiber bundle orientation; wherein the fiber-reinforcement structure comprises at least one third fiber woven between the at least one first fiber bundle and the at least one second fiber bundle.