High-temperature machine components, more particularly, articles capable of operating in high-temperature environments, including for example turbines of gas engines, may be formed of a high temperature ceramic matrix composite that includes a ceramic substrate including silicon; an environmental harrier coating system including a silicon containing bond coat; and a diffusion barrier layer of a carbide or a nitride between the substrate of the article and the silicon bond coat of the environmental barrier coating system. The diffusion harrier layer selectively prevents or reduces the diffusion of boron and impurities from the substrate to the bond coat of the environmental barrier coating system.

High-temperature machine components, more particularly, articles capable of operating in high-temperature environments, including for example turbines of gas engines, may be formed of a high temperature ceramic matrix composite that includes a ceramic substrate including silicon; an environmental harrier coating system including a silicon containing bond coat; and a diffusion barrier layer of a carbide or a nitride between the substrate of the article and the silicon bond coat of the environmental barrier coating system. The diffusion harrier layer selectively prevents or reduces the diffusion of boron and impurities from the substrate to the bond coat of the environmental barrier coating system.

A component includes a substrate at least a portion of which adjacent to a surface of the substrate is made of a material including silicon; a bond coat located on the surface of the substrate and including silicon, an environmental barrier which includes an outer layer of ceramic material covering the bond coat, wherein the environmental barrier further includes a self-healing inner layer located between the bond coat and the outer layer, the inner layer including a matrix in which silico-forming particles are dispersed, these particles being capable of generating a matrix crack healing phase in the presence of oxygen.

A component includes a substrate at least a portion of which adjacent to a surface of the substrate is made of a material including silicon; a bond coat located on the surface of the substrate and including silicon, an environmental barrier which includes an outer layer of ceramic material covering the bond coat, wherein the environmental barrier further includes a self-healing inner layer located between the bond coat and the outer layer, the inner layer including a matrix in which silico-forming particles are dispersed, these particles being capable of generating a matrix crack healing phase in the presence of oxygen.

A thermal barrier coating includes a highly porous layer and a dense layer. The highly porous layer is formed on a heat-resistant base, is made of ceramic, has pores, has a layer thickness of equal to or larger than 0.3 mm and equal to or smaller than 1.0 mm, and has a pore ratio of equal to or higher than 1 vol % and equal to or lower than 30 vol %. The dense layer is formed on the highly porous layer, is made of ceramic, has a pore ratio of equal to or lower than 0.9 vol % that is equal to or lower than the pore ratio of the highly porous layer, and has a layer thickness of equal to or smaller than 0.05 mm.

A spraying material comprising a rare earth (R), aluminum and oxygen, the spraying material being a powder and comprising a crystalline phase of a rare earth (R) aluminum monoclinic (R.sub.4Al.sub.2O.sub.9) and a crystalline phase of a rare earth oxide (R.sub.2O.sub.3), with respect to diffraction peaks detected within a diffraction angle 2 range from 10 to 70 by a X-ray diffraction method using the characteristic X-ray of Cu-K, the spraying material having diffraction peaks attributed to the rare earth oxide (R.sub.2O.sub.3) and diffraction peaks attributed to the rare earth (R) aluminum monoclinic (R.sub.4Al.sub.2O.sub.9), and an intensity ratio I(R)/I(RAL) of an integral intensity I(R) of the maximum diffraction peak attributed to the rare earth oxide (R.sub.2O.sub.3) to an integral intensity I(RAL) of the maximum diffraction peak attributed to the rare earth aluminum monoclinic (R.sub.4Al.sub.2O.sub.9) being at least 1.

A spraying material comprising a rare earth (R), aluminum and oxygen, the spraying material being a powder and comprising a crystalline phase of a rare earth (R) aluminum monoclinic (R.sub.4Al.sub.2O.sub.9) and a crystalline phase of a rare earth oxide (R.sub.2O.sub.3), with respect to diffraction peaks detected within a diffraction angle 2 range from 10 to 70 by a X-ray diffraction method using the characteristic X-ray of Cu-K, the spraying material having diffraction peaks attributed to the rare earth oxide (R.sub.2O.sub.3) and diffraction peaks attributed to the rare earth (R) aluminum monoclinic (R.sub.4Al.sub.2O.sub.9), and an intensity ratio I(R)/I(RAL) of an integral intensity I(R) of the maximum diffraction peak attributed to the rare earth oxide (R.sub.2O.sub.3) to an integral intensity I(RAL) of the maximum diffraction peak attributed to the rare earth aluminum monoclinic (R.sub.4Al.sub.2O.sub.9) being at least 1.

A method of fabricating a coating includes providing a ceramic matrix composite that includes SiC fibers disposed in a SiC matrix, depositing a base slurry on the ceramic matrix composite, wherein the base slurry contains powders of a metal oxide, at least one of silicon carbide, silicon nitride, or free silicon, and barium-magnesium-aluminosilicate in a first carrier fluid, drying the deposited base slurry to produce a base green layer, depositing a transition slurry on the base green layer, wherein the transition slurry contains powders of a metal oxide, at least one of silicon carbide, silicon nitride, or free silicon, at least one of zirconium carbide, zirconium nitride, or zirconium oxide, and barium-magnesium-aluminosilicate in a second carrier fluid, drying the deposited transition slurry to produce a transition green layer, and forming a consolidated coating on the ceramic matrix composite by heating the base green layer and the at least one transition green layer to cause chemical reactions that convert the powders to metal-silicon-oxygen rich phase and metal-zirconium-oxygen rich phase.

A coating method includes depositing a slurry including a coarsely particulate ceramic and a finely particulate ceramic on a base material configured with an oxide-based ceramics matrix composite such that a proportion of coarse particles decreases towards a surface of the base material; forming a bond coating by performing a heat treatment on the base material on which the slurry has been deposited; and forming a top coating by thermally spraying a ceramic onto the bond coating. The oxide-based ceramics matrix composite is an alumina silica type oxide-based ceramics matrix composite. The coarsely particulate ceramic and the finely particulate ceramic are alumina-based powder.

A coating method includes depositing a slurry including a coarsely particulate ceramic and a finely particulate ceramic on a base material configured with an oxide-based ceramics matrix composite such that a proportion of coarse particles decreases towards a surface of the base material; forming a bond coating by performing a heat treatment on the base material on which the slurry has been deposited; and forming a top coating by thermally spraying a ceramic onto the bond coating. The oxide-based ceramics matrix composite is an alumina silica type oxide-based ceramics matrix composite. The coarsely particulate ceramic and the finely particulate ceramic are alumina-based powder.