A coating is formed on a surface of a base material of a furnace, and includes a base layer and a sliding material layer that is formed on a surface of the base layer and contains an oxide ceramic and a compound having a layered crystal structure. The sliding material layer causes the collided ashes to be slipped and facilitates the drop off of the adhered ashes. The base material forms a heat transfer tube or a wall surface of the furnace. The coating is also applied to a coal gasification furnace, a pulverized coal fired boiler, a combustion apparatus, or a reaction apparatus containing a furnace.

A method for forming an oxidation protection system on a composite structure is provided, which may comprise applying a ceramic layer slurry to the composite structure, wherein the ceramic layer slurry may comprise aluminum and silicon in a solvent or carrier fluid; heating the composite structure to form a ceramic layer on the composite structure, wherein the ceramic layer may comprise aluminum nitride; applying a sealing slurry to the composite structure, wherein the sealing slurry may comprise a sealing pre-slurry composition and a sealing carrier fluid, wherein the sealing pre-slurry composition may comprise a sealing phosphate glass composition; and/or heating the composite structure to form a sealing layer on the composite structure.

A method for forming an oxidation protection system on a composite structure is provided, which may comprise applying a ceramic layer slurry to the composite structure, wherein the ceramic layer slurry may comprise aluminum and silicon in a solvent or carrier fluid; heating the composite structure to form a ceramic layer on the composite structure, wherein the ceramic layer may comprise aluminum nitride; applying a sealing slurry to the composite structure, wherein the sealing slurry may comprise a sealing pre-slurry composition and a sealing carrier fluid, wherein the sealing pre-slurry composition may comprise a sealing phosphate glass composition; and/or heating the composite structure to form a sealing layer on the composite structure.

A cubic boron nitride sintered body including cubic boron nitride and a binder phase, wherein a content of the cubic boron nitride is 40 volume % or more and 70 volume % or less; a content of the binder phase is 30 volume % or more and 60 volume % or less; an average particle size of the cubic boron nitride is 0.1 μm or more and 3.0 μm or less; the binder phase contains TiN and/or TiCN, and TiB.sub.2 and contains substantially no AIN and/or Al.sub.2O.sub.3, the binder phase has a TiB.sub.2 (101) plane that shows a maximum peak position (2θ) in X-ray diffraction of 44.2° or more; and I.sub.2/I.sub.1 is 0.10 or more and 0.55 or less, where denotes an X-ray diffraction intensity of a (111) plane of the cubic boron nitride and I.sub.2 denotes an X-ray diffraction intensity of a (101) plane of TiB.sub.2 of the binder phase.

An oxidation protection system disposed on a substrate is provided, which may comprise a boron layer comprising a boron compound disposed on the substrate; a silicon layer comprising a silicon compound disposed on the boron layer; and at least one sealing layer comprising monoaluminum phosphate and phosphoric acid disposed on the silicon layer.

An oxidation protection system disposed on a substrate is provided, which may comprise a boron layer comprising a boron compound disposed on the substrate; a silicon layer comprising a silicon compound disposed on the boron layer; and at least one sealing layer comprising monoaluminum phosphate and phosphoric acid disposed on the silicon layer.

The present disclosure provides a method for coating a composite structure comprising the steps of applying a first slurry of a first phosphate glass composition on an outer surface of the composite structure. The first slurry comprises a first additive including at least one of molybdenum disulfide or tungsten disulfide. The method may further include heating the composite structure to a temperature sufficient to form a base layer adhered to the composite structure.

The present disclosure provides a method for coating a composite structure comprising the steps of applying a first slurry of a first phosphate glass composition on an outer surface of the composite structure. The first slurry comprises a first additive including at least one of molybdenum disulfide or tungsten disulfide. The method may further include heating the composite structure to a temperature sufficient to form a base layer adhered to the composite structure.

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.