Ceramic matrix composite articles include, for example, a plurality of unidirectional arrays of fiber tows in a matrix having a monomodal pore size distribution, and a fiber volume fraction between about 15 percent and about 35 percent. The articles may be formed by, for example, providing a shaped preform comprising a prepreg tape layup of unidirectional arrays of fiber tows, a matrix precursor, and a pore former, curing the shaped preform to pyrolyze the matrix precursor and burnout the pore former so that the shaped preform comprises the unidirectional arrays of fiber tows and a porous matrix having a monomodal pore size distribution, and subjecting the cured shaped preform to chemical vapor infiltration to densify the porous matrix so that the ceramic matrix composite article has a fiber volume fraction between about 15 percent and about 35 percent.

Disclosed is a method for improving the high-temperature stability of a component, in particular a blade of a turbomachine, formed at least partially from a molybdenum alloy that, besides molybdenum, silicon, boron and titanium, comprises iron and/or yttrium. The method comprises depositing a diffusion barrier layer formed from technically pure molybdenum or tungsten or being an alloy based on molybdenum and/or tungsten at least on an outer surface, which comprises the molybdenum alloy, of the component, and depositing silicon on the diffusion barrier layer to form molybdenum silicides and/or tungsten silicides.

An airfoil comprises a wall that defines a leading edge and a trailing edge and one or more cavities located within the wall along with a rib that separates the cavities. The rib or the wall comprises a first split ply that comprises a consolidated section and two or more split sections; wherein the split sections emanate from the consolidated section; and where the split sections define the wall and the cavities of the airfoil.

A method of preparing a fiber for use in forming a ceramic matrix composite material comprises the steps of removing a polymer coating from an outer surface of glass or ceramic fibers by providing heated and humidified gas across the glass or ceramic fibers for a period of time.

A method of repairing an article including cleaning a repair area, wherein the repair area comprises a ceramic matrix composite; and depositing a ceramic material in the cleaned repair area using laser assisted chemical vapor deposition. Also disclosed is a repaired ceramic composite produced by this method.

A gas turbine engine includes: a turbine section including a casing extending circumferentially about a plurality of turbine blades and having at least one seal member coated with an abradable coating. At least one turbine blade has sides and a tip and at least one seal member is located adjacent to the tip of the at least one turbine blade. The tip of the at least one turbine blade has a wear resistant layer and an abrasive coating disposed on the wear resistant layer. The wear resistant layer has a thickness less than or equal to 10 mils (254 micrometers) and includes metal boride compounds.

A gas turbine engine includes an engine static structure extending circumferentially about an engine centerline axis; a compressor section, a combustor section, and a turbine section within the engine static structure. At least one of the compressor section and the turbine section includes at least one airfoil and at least one seal member adjacent to the at least one airfoil. A tip of the at least one airfoil is metal having a wear resistant coating and the at least one seal member is coated with an abradable coating. The wear resistant coating is formed as a layer in a base metal surface of the airfoil, has a thickness less than or equal to 10 mils (254 micrometers) and includes metal boride compounds.

The invention relates to a part made of silicon-based ceramic material or silicon-based ceramic matrix composite (CMC) material comprising an environmental barrier coating (EBC), said coating (12, 13) comprising a bonding layer (12) deposited on the surface of the ceramic material or ceramic matrix composite (CMC), said bonding layer (12) being topped by one or more layers together forming a multifunctional barrier structure (13), characterised in that the bonding layer (12) has at its interface with the multifunctional structure a polycrystalline silica layer (12) or sub-layer (12b).

A gas turbine engine component includes a gas turbine engine component body formed of a ceramic matrix composite material having at least one fastener integrally formed with the gas turbine engine component body as a single-piece structure. The gas turbine engine component body initially comprises a rigidized preform structure formed from a polymer based material. The at least one fastener connects the gas turbine engine component body to an engine support structure.

A method comprises discharging from a metal vaporization device a vapor of a metal or a metal precursor to a chemical vapor infiltration device where the chemical vapor infiltration device is in fluid communication with the metal vaporization device. The chemical vapor infiltration device contains a preform containing ceramic fibers. The preform is infiltrated with a metallic coating or a coating of a metallic precursor along with a ceramic precursor coating. The metallic coating and/or the metallic precursor coating and the ceramic precursor coating are applied sequentially or simultaneously.