Abstract: The invention concerns an article (20) formed of a ceramic matrix composite structure having a plurality of ceramic fibre layers (22) and a binder material (24) interspersed throughout said layers. The ceramic matrix composite material may be sintered. The ceramic fibre layers undulate relative to one or more outer surfaces (38;40) of the article. Thus support features (48) within the article are able to share a load in use between a plurality of layers. The invention may be suited to engine components such as turbine seal segments in a gas turbine engine.

Abstract: A seal segment is provided for a shroud ring of a rotor of a gas turbine engine. The seal segment is positioned, in use, radially adjacent the rotor. The seal segment has two or more spaced passageways. In use, a respective support bar can be contained within each passageway. The support bars allow attachment of the seal segment to the engine casing. Each passageway has an elliptical or substantially elliptical cross-section with a minor diameter and a major diameter, the minor diameter being substantially aligned with the radial direction. The respective support bar has a correspondingly elliptical or substantially elliptical cross-section for a close fit in the passageway.

Abstract: A seal segment is provided for a shroud ring of a rotor of a gas turbine engine. The seal segment is positioned, in use, radially adjacent the rotor. The seal segment includes a body portion having front and rear sides which each contain a respective slot that extends in the circumferential direction so that a respective hook formation is insertable into each slot for attaching the seal segment to the engine casing. The body portion is formed from continuous fibre reinforced ceramic matrix composite, reinforcing fibres of the composite wrapping around each slot so that, at the base of the slot, the reinforcing fibres are parallel to the surface of the body portion.

Abstract: A method of forming a ceramic matrix composite component is provided. The method includes the steps of: providing a pattern element; coating the pattern element with a ceramic slurry; drying the slurry to form a ceramic layer; forming a ceramic matrix composite body on a surface of the ceramic layer to produce a ceramic matrix composite component with the ceramic layer attached thereto.

Abstract: A component of a gas turbine engine is formed from a continuous fibre reinforced ceramic matrix composite (CMC). The component has a sealing portion which, in use, makes sealing contact with an adjacent component of the engine. The sealing portion comprises a recess formed in the CMC and filled with a finer grade ceramic relative to the surrounding CMC, a metal or an intermetallic.

Abstract: A method of forming a ceramic matrix composite gas turbine engine includes: providing green sub-elements, each sub-element containing stacked plys of continuous fibre reinforcement embedded in a green ceramic matrix; assembling the sub-elements so that each sub-element contacts at least one other; and sintering the assembled sub-elements to fuse the ceramic matrix within each sub-element and between contacting sub-elements, forming a composite unitary body. An alternative method includes the steps of: providing a sintered sub-elements, each sub-element containing stacked plys of continuous fibre reinforcement embedded in a sintered ceramic matrix; assembling the sintered sub-elements so that each sub-element contacts at least one other, ceramic cement being provided at the contact interfaces between the sub-elements; and the assembled sub-elements to fuse the ceramic cement, forming a ceramic matrix composite unitary body.

Abstract: A seal segment is positioned, in use, radially adjacent the rotor. The seal segment has first and second circumferentially spaced passageways each of which extends in the fore and aft direction. In use, a first support bar is contained within the first passageway, and a second support bar is contained within the second passageway. The first and second support bars being mountable to complementary formations provided by the casing of the engine. The first passageway is configured such that the seal segment is fixed relative to the first support bar in the radial and circumferential directions. The second passageway is configured such that the seal segment is fixed relative to the second support bar in the radial direction but allows relative movement of the seal segment and the second support bar in the circumferential direction to accommodate differential thermal expansion of the seal segment and the casing.

Abstract: A fastener is provided for connecting two or more structural elements having matching apertures which, when aligned, form a frusto-conical cavity. The fastener includes a body portion having a frusto-conical outer surface which is receivable in the aligned apertures of the structural elements such that the outer surface of the body portion is in mating engagement with the cavity formed by the aligned apertures. The fastener further includes an elongate member which extends from the body portion at the narrow end of the frusto-conical outer surface. The fastener further includes a fixing element carried by the elongate member. The fixing element is operable to exert a clamping force between the frusto-conical outer surface and the fixing element to retain the structural elements in connection therebetween. The fastener further includes a through-hole which extends along the elongate member and which allows fluid communication between opposing sides of the connected structural elements.

Abstract: This invention relates to heat transfer passage (102) within a component (100) and a component having such a heat transfer passage. The passage (102) comprises opposing side walls (112), a base (110) extending between said side walls and one or more upstanding formations (122) depending from said base between said side walls. The passage is arranged to receive a heat transfer fluid flow during use and the upstanding formation (122) is arranged to induce separation of a boundary layer portion of said heat transfer fluid flow from the base in use. The upstanding formation (122) comprises a projection portion (126) which is spaced from said opposing side walls (112). Such upstanding formations are typically referred to as turbulators.

Abstract: This invention relates to heat transfer passage (102) within a component (100) and a component having such a heat transfer passage. The passage (102) comprises opposing side walls (112), a base (110) extending between said side walls and one or more upstanding formations (122) depending from said base between said side walls. The passage is arranged to receive a heat transfer fluid flow during use and the upstanding formation (122) is arranged to induce separation of a boundary layer portion of said heat transfer fluid flow from the base in use. The upstanding formation (122) comprises a projection portion (126) which is spaced from said opposing side walls (112). Such upstanding formations are typically referred to as turbulators.

Abstract: Vanes are generally hollow with a passage through which service pipes extend. These service pipes must be connected such that they can allow for thermal expansion and contraction but also anti rotation features are needed in order to prevent damage when a supply coupling is connected through a pipe end. This anti-rotation feature is generally provided between a top hat and a pipe end through flanges. In order to allow reduced spacing between the top of the vane and a casing the flanges are arranged to allow at least recessing of a first flange into a passage opening profile whereby those flanges inter-engage with second flanges at a surface interface to prevent rotation.