Abstract: Disclosed herein is a composite co-fiber comprising a plurality of ceramic tows; one or more sacrificial yarns; where the sacrificial yarns are operative to undergo dissolution, decomposition or melting upon being subjected to an elevated temperature; and wherein the sacrificial yarns leave open spaces in the co-fiber upon being subjected to decomposition, dissolution or melting.

Abstract: Disclosed herein is a ceramic matrix composite airfoil comprising a triple bifurcated ply that defines a suction side, an outer platform, a pressure side and an inner platform of the airfoil, wherein the triple bifurcated ply comprises at least one ply that comprises a consolidated region, wherein the consolidated region is split into two bifurcated regions in three locations in three different directions.

Abstract: Disclosed herein is a ceramic matrix composite airfoil comprising a triple bifurcated ply that defines a suction side, an outer platform, a pressure side and an inner platform of the airfoil, wherein the triple bifurcated ply comprises at least one ply that comprises a consolidated region, wherein the consolidated region is split into two bifurcated regions in three locations in three different directions.

Abstract: A method of forming a ceramic matrix composite component according to an exemplary embodiment of this disclosure, among other possible things includes laying up plies of ceramic reinforcement material with sacrificial plies to form a preform, infiltrating the preform with a ceramic matrix material, and machining away the sacrificial plies to reveal a surface profile of the ceramic matrix composite component. A preform for a ceramic matrix composite component is also disclosed.

Abstract: A seal assembly for a gas turbine engine includes a seal including a main body extending circumferentially between opposed mate faces. The main body has a sealing portion and an engagement portion extending outwardly from sealing portion along at least one of the mate faces. The main body has a core including one or more core plies arranged to establish an internal cavity. An overwrap has one or more overwrap plies arranged to follow a perimeter of the one or more core plies to establish the engagement portion and the sealing portion. A platform insert extends between portions of the core and the overwrap to establish the sealing portion. A method of fabricating a seal for a gas turbine engine is also disclosed.

Abstract: A waterjet-guided laser machine includes a laser source, an LED, a waterjet head, and a light sensor. The waterjet head includes a water inlet and a nozzle having an outlet for a discharging a waterjet. There is a laser optical path along which a pulsed laser beam travels to the nozzle outlet. There is also a light beam optical delivery path along which the light beam travels from the LED to the nozzle outlet. The light beam optical delivery path is coincident with the laser optical path in the nozzle. There is a light beam optical return path along which the light beam that is reflected off of a workpiece travels to the light sensor. The light beam optical return path is coincident with the laser optical path inside the nozzle and coincident with the light beam optical delivery path inside the nozzle.

Abstract: A method of machining cooling holes includes providing a workpiece in which a cooling hole is to be formed. The cooling hole, once formed, defines distinct first and second sections. The workpiece is secured in a fixture that is mounted in a first machine. In the first machine, a laser is used to drill a through-hole in a wall of the workpiece. The through-hole is spatially common to the first and second sections of the cooling hole. After drilling the through-hole, the fixture with the workpiece secured therein is removed from the first machine and mounted in a second machine. In the second machine, ultrasonic machining is used to expand a portion of the through-hole to form the second section. An abrasive slurry used in the process is drained through the through-hole during the ultrasonic machining.

Abstract: A method is provided for machining a workpiece. During this machining method, an aperture is formed in the workpiece using a machining system. The machining system includes an ultrasonic machining device, a slurry delivery device and a controller. The forming of the aperture includes delivering a slurry to an interface between the ultrasonic machining device and the workpiece using the slurry delivery device, and transmitting ultrasonic vibrations into the slurry using the ultrasonic machining device. A feedback parameter is monitored during the forming of the aperture using the controller. A slurry delivery parameter for the slurry delivery device is adjusted during the forming of the aperture based on the feedback parameter using the controller.

Abstract: A method of spreading fiber tows includes assembling a fibrous composite from a plurality of tows, applying an aqueous solution to the fibrous composite, freezing the fibrous composite after applying the aqueous solution, freeze drying the fibrous composite to remove water from the fibrous composite, and heating the fibrous composite after freeze drying to remove a cryoprotectant from the fibrous composite. The aqueous solution comprises water and the cryoprotectant and freezing the fibrous composite spreads filaments within the plurality of fiber tows.

Abstract: A method for machining a ceramic workpiece includes providing a sonotrode that has a transducer and a horn arranged along an axis, and the horn has helical slots and terminates at a tip, bringing the tip into proximity of the ceramic workpiece and providing an abrasive media to a work zone around the tip, using the transducer to produce ultrasonic vibration that axially propagates down the horn and causes axial vibration at the tip, and the helical slots convert a portion of the axial vibration to torsional vibration at the tip, and the axial vibration and the torsional vibration causing the abrasive media to abrade the ceramic workpiece in the work zone and thereby remove a localized portion of the ceramic workpiece.

Abstract: A method of machining includes removing material from a target region of a ceramic component to form a blind opening in the ceramic component via removing a bulk of the material by a laser machining operation and then removing a remainder of the material by a mechanical machining operation.

Abstract: A method of machining includes mounting a component in a drilling machine. The component has a target region where the hole is to be drilled. The component and a jet head are situated relative to each other in a drilling arrangement in which the target region is at a first position that is vertically equal to or vertically above a second position at which the jet head is located. A liquid stream is jetted from the jet head and contains either abrasive particles or a laser beam. The stream impinges the target region, and the abrasive particles or the laser beam cause removal of material from the component to form the hole. The liquid stream rebounds off of the component as back-splash. The drilling arrangement causes gravitational draining of the back-splash from the target region to reduce interference between the back-splash and the liquid stream.

Abstract: A method for forming a hole in a ceramic matrix composite component includes providing a first tool component with a first hole, providing a fiber preform of the ceramic matrix composite component on the first tool component, positioning a second tool component on the fiber preform, such that the fiber preform is disposed between the first and second tool components, inserting a rod into the first and second holes and through the fiber preform, and performing a densification step of the fiber preform in the first and second tool components. The second tool component has a second hole coaxial with the first hole. The fiber preform is densified with a ceramic matrix.

Abstract: A flow path component assembly includes a flow path component having a plurality of segments that extend circumferentially about an axis and mounted in a support structure. At least one of the plurality of segments have a first wall and a second wall that extend radially outward from a base portion. The first wall is axially spaced from the second wall. A coating is on a portion of the first wall and a portion of the second wall. The coating is in contact with a feature on the support structure.

Abstract: A seal assembly for a gas turbine engine according to an example of the present disclosure includes a seal that has a main body extending circumferentially between opposed mate faces. The main body has a sealing portion and an engagement portion extending outwardly from sealing portion along at least one of the mate faces. The main body has a core that has one or more core plies having a first fiber construction and arranged to establish an internal cavity. An overwrap has one or more overwrap plies having a second fiber construction and arranged to follow a perimeter of the one or more core plies to establish the engagement portion and the sealing portion, and the second fiber construction differs from the first fiber construction. The first fiber construction establishes a first target fiber volume fraction, the second fiber construction establishes a second target fiber volume fraction. A method of fabricating a seal for a gas turbine engine is also disclosed.

Abstract: A seal assembly for a gas turbine engine according to an example of the present disclosure includes, among other things, a seal that has a main body extending circumferentially between opposed mate faces. The main body has a sealing portion and an engagement portion extending outwardly from sealing portion along at least one of the mate faces. The main body includes one or more braided core plies having a first fiber construction and arranged to establish an internal cavity. An overwrap having one or more braided overwrap plies follows a perimeter of the one or more braided core plies to establish the engagement portion and the sealing portion. The one or more braided overwrap plies have a second fiber construction differing from the first fiber construction. A method of fabricating a seal for a gas turbine engine is also disclosed.

Abstract: A seal assembly for a gas turbine engine includes a seal including a main body extending circumferentially between opposed mate faces. The main body has a sealing portion and an engagement portion extending outwardly from sealing portion along at least one of the mate faces. The main body has a core including one or more core plies arranged to establish an internal cavity. An overwrap has one or more overwrap plies arranged to follow a perimeter of the one or more core plies to establish the engagement portion and the sealing portion. A platform insert extends between portions of the core and the overwrap to establish the sealing portion. A method of fabricating a seal for a gas turbine engine is also disclosed.

Abstract: A seal assembly for a gas turbine engine includes a seal including a main body extending circumferentially between opposed mate faces. The main body has a sealing portion and an engagement portion extending outwardly from sealing portion along at least one of the mate faces. The main body has a core including one or more core plies arranged to establish an internal cavity. An overwrap has one or more overwrap plies arranged to follow a perimeter of the one or more core plies to establish the engagement portion and the sealing portion. A platform insert extends between portions of the core and the overwrap to establish the sealing portion. A method of fabricating a seal for a gas turbine engine is also disclosed.

Abstract: A flow path component assembly includes a flow path component having a plurality of segments that extend circumferentially about an axis and mounted in a support structure. At least one of the plurality of segments have a first wall and a second wall that extend radially outward from a base portion. The first wall is axially spaced from the second wall. A coating is on a portion of the first wall and a portion of the second wall. The coating is in contact with a feature on the support structure.

Abstract: A seal assembly for a gas turbine engine according to an example of the present disclosure includes a seal that has a main body extending circumferentially between opposed mate faces. The main body has a sealing portion and an engagement portion extending outwardly from sealing portion along at least one of the mate faces. The main body has a core that has one or more core plies having a first fiber construction and arranged to establish an internal cavity. An overwrap has one or more overwrap plies having a second fiber construction and arranged to follow a perimeter of the one or more core plies to establish the engagement portion and the sealing portion, and the second fiber construction differs from the first fiber construction. The first fiber construction establishes a first target fiber volume fraction, the second fiber construction establishes a second target fiber volume fraction. A method of fabricating a seal for a gas turbine engine is also disclosed.