A ceramic matrix composite (CMC) is formed using a three-dimensional (3-D) woven preform by removing the set of sacrificial fibers from the 3-D woven preform and allowing a metal or metal alloy infiltrate the 3-D woven preform. The 3-D woven preform is formed by a method that includes providing a woven layer comprising a first set of ceramic fibers oriented in a first (x) direction woven with a second set of ceramic fibers oriented in a second (y) direction; stacking a plurality of woven layers on top of each other, said woven layers providing a two-dimensional (2-D) preform; weaving a set of sacrificial fibers in a third (z) direction with the 2-D preform, said weaving providing the 3-D woven preform; and shaping the 3-D woven preform into a predetermined shape.

The present invention relates to a process for producing a fiber-reinforced three-dimensional ceramic component allowing for a targeted orientation of the reinforcing fibers, a slip for use in said process according to the invention, and a device for carrying out the process according to the invention.

A method of forming a ceramic matrix composite includes three-dimensionally weaving a fibrous preform, the preform including a plurality of warp tows, a plurality of weft tows, and a plurality of z-fibers passing orthogonally between the plurality of warp and the plurality of weft tows. The method further includes debulking the preform, decomposing the plurality of z-fibers to form a respective plurality of z-channels in the preform, and densifying the preform with a ceramic matrix.

Disclosed is a hydraulically and chemically bonding refractory cement, which includes a caustic magnesia component having a BET specific surface area of at least 0.5 m.sup.2/g, and a carboxylic acid component, wherein the carboxylic acid component consists of at least one carboxylic acid that is only slightly water soluble and/or has a low dissolution rate in aqueous solutions, and which carboxylic acid component is capable of generating at least one soluble magnesium salt upon contact of the cement with water. Also disclosed is a corresponding refractory material containing the magnesia cement and to uses thereof for the manufacture of products useful in various industries.

A cementitious composition includes (i) white Portland cement having a fineness of about 350-550 m.sup.2/kg, D90 between about 11-50 m, and total combined iron oxide, manganese oxide, and chromium oxide <1.0% by weight (ii) light color pozzolan such as white silica fume, and (iii) at least one light color particulate material, such as ground granulated blast furnace slag (GGBFS) having a fineness greater than that of the white Portland cement, a D90 less than that of the white Portland cement, and total combined iron oxide, manganese oxide, and chromium oxide content <3.0% by weight and/or coarse limestone powder having a D90 greater than that of the white cement. The cementitious composition may include one or more of aggregates, fibers, or admixture. The cementitious composition can be a dry blend, fresh cementitious mixture, or hardened cementitious composition. The cementitious composition can be precast concrete, stucco, GFRC, UHPC or SCC.

A method for forming a hole in a ceramic matrix composite (CMC) component may be provided. A sacrificial fiber having an environmental barrier coating on an outer surface thereof may be inserted into a porous ceramic preform that includes ceramic fibers. The ceramic preform may be formed into a ceramic matrix composite body. The sacrificial fiber may be removed from the ceramic matrix composite body, the environmental barrier coating of the sacrificial fiber defining an opening in the ceramic matrix composite body. A ceramic matrix composite component may be provided. The ceramic matrix composite component may include an environmental barrier coating of a sacrificial fiber, where the environmental barrier coating forms a lining of a hole passing partly or entirely through a thickness of the ceramic matrix composite body.

A technique of heating a mixture of fibers that includes sacrificial fibers and carbon fiber precursor fibers to a temperature between about 170 C. and about 400 C., such that the sacrificial fibers are substantially removed and a plurality of channels remain in a preform precursor, and carbonizing the carbon fiber precursor fibers to form a porous carbon fiber preform. Also disclosed is a technique of heating a mixture of fibers that includes sacrificial fibers and carbon fibers to a temperature between about 170 C. and about 400 C., such that the sacrificial fibers are substantially removed and a plurality of channels remain, and infiltrating a densifying agent into at least the plurality of channels. Also disclosed is an article including a mixture of fibers that includes sacrificial fibers and carbon fiber precursor fibers or carbon fibers.

The invention relates to a batch for producing an unshaped refractory ceramic product, to a method for producing a fired refractory ceramic product, to a fired refractory ceramic product and to the use of an unshaped refractory ceramic product.

Silicon carbide composite materials contain CSiC with a density of 2.95 to 3.05 g/cm.sup.3 and a fiber bundle content of 2 to 10 wt. %. The fiber bundles have a length of 6 to 20 mm, a width of 0.2 to 3 mm, and a thickness of 0.1 to 0.8 mm. The fiber bundles are filled with a cured phenolic resin content of up to 45 wt. %, and the protected fiber bundles are integrated into an SiC matrix. A method produces the silicon carbide composite materials.

A stiffness controlled abradeable seal system for a gas turbine engine includes a cantilevered arm that supports one of a rotating seal surface and a static seal surface, a stiffness of the cantilevered arm controlled to achieve a desired operational temperature at a seal interface.