The present disclosure provides a method for coating a composite structure, comprising forming a first slurry by combining a first pre-slurry composition with a first carrier fluid, applying the first slurry on a surface of the composite structure, and heating the composite structure to a temperature sufficient to form a base layer on the composite structure. The first pre-slurry composition may comprise a first phosphate glass composition and a low coefficient of thermal expansion material, wherein the low coefficient of thermal expansion material is a material with a coefficient of thermal expansion of less than 10×10.sup.−6° C..sup.−1.

The present disclosure provides a method for coating a composite structure, comprising forming a first slurry by combining a first pre-slurry composition with a first carrier fluid, applying the first slurry on a surface of the composite structure, and heating the composite structure to a temperature sufficient to form a base layer on the composite structure. The first pre-slurry composition may comprise a first phosphate glass composition and a low coefficient of thermal expansion material, wherein the low coefficient of thermal expansion material is a material with a coefficient of thermal expansion of less than 10×10.sup.−6° C..sup.−1.

The present disclosure provides a method for coating a composite structure, comprising applying a first slurry on a surface of the composite structure, heating the composite structure to a temperature sufficient to form a base layer on the composite structure, forming a sealing slurry comprising at least one of acid aluminum phosphate or orthophosphoric acid, applying the sealing slurry to the base layer, and heating the composite structure to a second temperature sufficient to form a sealing layer on the base layer.

The present disclosure provides a method for coating a composite structure, comprising applying a first slurry on a surface of the composite structure, heating the composite structure to a temperature sufficient to form a base layer on the composite structure, forming a sealing slurry comprising at least one of acid aluminum phosphate or orthophosphoric acid, applying the sealing slurry to the base layer, and heating the composite structure to a second temperature sufficient to form a sealing layer on the base layer.

This application describes a method of making a super-hard article that includes a super-hard structure bonded to a substrate. The super-hard structure generally includes a sintered plurality of super-hard grains made from cubic boron nitride. The method generally includes providing raw material powder suitable for sintering the super-hard structure; combining the raw material powder with an organic binder material in a liquid medium to form a paste; providing a substrate assembly having a formation surface area configured for forming a boundary of the super-hard structure, the substrate having a recess coterminous with the formation surface area; extruding the paste into contact with the formation surface area to provide a paste assembly; and heat treating and/or sintering the paste assembly to remove the binder material and provide a pre-sinter assembly.

A method of making a ceramic matrix composite that exhibits chemical resistance has been developed. The method comprises depositing a compliant layer comprising boron nitride, silicon-doped boron nitride, and/or pyrolytic carbon on silicon carbide fibers, depositing a barrier layer having a high contact angle with molten silicon on the compliant layer, and depositing a wetting layer comprising silicon carbide, boron carbide, and/or pyrolytic carbon on the barrier layer. After depositing the wetting layer, a fiber preform comprising the silicon carbide fibers is infiltrated with a slurry. After slurry infiltration, the fiber preform is infiltrated with a melt comprising silicon, and then the melt is cooled, thereby forming a ceramic matrix composite.

An oxidation protection system disposed on a substrate is provided, which may comprise a base layer comprising a first pre-slurry composition comprising a first phosphate glass composition, and/or a sealing layer comprising a second pre-slurry composition comprising a second phosphate glass composition and a strengthening compound comprising boron nitride, a metal oxide, and/or silicon carbide.

The present disclosure provides a method for coating a composite structure, comprising forming a first slurry by combining a glass frit comprising a first phosphate glass composition with a first carrier fluid comprising an acid aluminum phosphate, wherein the ratio of aluminum to phosphoric acid is between 1 to 2 and 1 to 3, applying the first slurry on a surface of the composite structure to form a base layer, and heating the composite structure to a temperature sufficient to adhere the base layer to the composite structure.

The present disclosure provides a method for coating a composite structure, comprising forming a first slurry by combining a glass frit comprising a first phosphate glass composition with a first carrier fluid comprising an acid aluminum phosphate, wherein the ratio of aluminum to phosphoric acid is between 1 to 2 and 1 to 3, applying the first slurry on a surface of the composite structure to form a base layer, and heating the composite structure to a temperature sufficient to adhere the base layer to the composite structure.

The present disclosure provides a method for coating a composite structure, comprising forming a first slurry by combining a first pre-slurry composition with a first carrier fluid, applying the first slurry on a surface of the composite structure, and heating the composite structure to a temperature sufficient to form a base layer on the composite structure. The first pre-slurry composition may comprise a first phosphate glass composition and a low coefficient of thermal expansion material, wherein the low coefficient of thermal expansion material is a material with a coefficient of thermal expansion of less than 10×10.sup.−6° C..sup.−1.