Provided is a tubular body containing SiC fibers having high thermal conductivity. The tubular body containing SiC fibers includes a SiC fiber layer wound in a tubular form, an inner SiC coating layer covering an inner surface of the SiC fiber layer, and an outer SiC coating layer covering an outer surface of the SiC fiber layer. The inner and outer SiC coating layers are bound to each other in gaps provided in the SiC fiber layer.

Provided is a tubular body containing SiC fibers having high thermal conductivity. The tubular body containing SiC fibers includes a SiC fiber layer wound in a tubular form, an inner SiC coating layer covering an inner surface of the SiC fiber layer, and an outer SiC coating layer covering an outer surface of the SiC fiber layer. The inner and outer SiC coating layers are bound to each other in gaps provided in the SiC fiber layer.

There is provided a fiber-reinforced brittle matrix composite. The fiber-reinforced brittle matrix composite comprises a brittle matrix material (for example, a cementitious or ceramics material) and a coated fiber embedded in the brittle matrix material, wherein the coated fiber comprises a fiber (for example, polyethylene fiber, glass fiber, silicon carbide fiber, alumina fiber, mullite fiber) and a coating material (for example, carbon nanofibers, carbon nanotubes), which is non-covalently disposed on the fiber. A method for producing the fiber-reinforced brittle matrix composite is also provided. The method comprises providing a fiber, disposing a coating material on the fiber to form a coated fiber, wherein the coating material is non-covalently disposed on the fiber, and embedding the coated fiber in a brittle matrix material to obtain the fiber-reinforced brittle matrix composite.

There is provided a fiber-reinforced brittle matrix composite. The fiber-reinforced brittle matrix composite comprises a brittle matrix material (for example, a cementitious or ceramics material) and a coated fiber embedded in the brittle matrix material, wherein the coated fiber comprises a fiber (for example, polyethylene fiber, glass fiber, silicon carbide fiber, alumina fiber, mullite fiber) and a coating material (for example, carbon nanofibers, carbon nanotubes), which is non-covalently disposed on the fiber. A method for producing the fiber-reinforced brittle matrix composite is also provided. The method comprises providing a fiber, disposing a coating material on the fiber to form a coated fiber, wherein the coating material is non-covalently disposed on the fiber, and embedding the coated fiber in a brittle matrix material to obtain the fiber-reinforced brittle matrix composite.

Inorganic coatings that may be used to coat and protect concrete are disclosed. The protective inorganic coatings include a liquid composition portion comprising water, an alkali metal oxide component and a silicate-containing component. The coatings also include a powder composition portion comprising microspheres, metal oxide powder and optional microfibers. When applied to concrete, the coatings provide chemical and physical protection.

Inorganic coatings that may be used to coat and protect concrete are disclosed. The protective inorganic coatings include a liquid composition portion comprising water, an alkali metal oxide component and a silicate-containing component. The coatings also include a powder composition portion comprising microspheres, metal oxide powder and optional microfibers. When applied to concrete, the coatings provide chemical and physical protection.

A fiber comprises a bulk material comprising one or more materials selected from the group consisting of carbon, silicon, boron, silicon carbide, and boron nitride; and a metal whose affinity for oxygen is greater than the affinity for oxygen of any of the one or more materials. The metal may be selected from the group consisting of beryllium, titanium, hafnium and zirconium. At least a first portion of the metal may be present in un-oxidized form at the entrance to and/or within grain boundaries within the fiber. A method of improving at least one of the strength, creep resistance, and toughness of a fiber comprises adding to a fiber, initially comprising a bulk material having a first affinity for oxygen, a metal that has a second affinity for oxygen higher than the first affinity. The metal may be selected from the group consisting of beryllium, titanium, hafnium and zirconium.

A fiber comprises a bulk material comprising one or more materials selected from the group consisting of carbon, silicon, boron, silicon carbide, and boron nitride; and a metal whose affinity for oxygen is greater than the affinity for oxygen of any of the one or more materials. The metal may be selected from the group consisting of beryllium, titanium, hafnium and zirconium. At least a first portion of the metal may be present in un-oxidized form at the entrance to and/or within grain boundaries within the fiber. A method of improving at least one of the strength, creep resistance, and toughness of a fiber comprises adding to a fiber, initially comprising a bulk material having a first affinity for oxygen, a metal that has a second affinity for oxygen higher than the first affinity. The metal may be selected from the group consisting of beryllium, titanium, hafnium and zirconium.

A gas turbine engine includes a rotatable component and a non-rotatable component. A seal is carried on one of the rotatable component or the non-rotatable component to provide sealing there between. The seal includes a geopolymer seal element.

Techniques for infiltrating a CMC substrate may include infiltrating the CMC substrate with a first slurry to at least partially fill at least some inner spaces of the CMC substrate, where the first slurry includes first solid particles, drying the first slurry to form an infiltrated CMC including the first solid particles, depositing a second slurry including a carrier material and second solid particles on a surface of the infiltrated CMC, where the second solid particles include a plurality of fine ceramic particles, a plurality of coarse ceramic particles, and a plurality of diamond particles, drying the second slurry to form an article having an outer surface layer including the second solid particles on the infiltrated CMC, and infiltrating the article with a molten infiltrant to form a composite article.