Abstract: In various aspects, a preheater, a directed flow chemical vapor infiltration/chemical vapor deposition (CVI/CVD) furnace, and/or an installation jig are described. In one example, a preheater includes a central inlet; a circuitous gas flow path downstream of the central inlet; a plenum section downstream of the circuitous gas flow path; and an outlet diffuser plate defining a plurality of apertures fluidly configured to couple the preheater to a furnace working zone, wherein the outlet diffuser plate is downstream of the plenum section, wherein the circuitous gas flow path is fluidly coupled to the plenum section by an outer circumferential slot opening.

Abstract: Methods of pressure assisted melt infiltration of fiber preforms are provided. The fiber preform is provided inside of a pressure vessel. The pressure vessel projects into a molten material contained in a crucible. The pressure vessel has an opening located below a surface of the molten material through which the molten material enters the pressure vessel. An end of the fiber preform contacts the molten material within the pressure vessel. The pressure vessel and crucible are located in a furnace. The molten material is pulled within the pressure vessel by increasing a first pressure at a first port of the furnace so the first pressure is higher than a second pressure at a second port of the pressure vessel. The second port is located above the molten material located within the pressure vessel. The fiber preform is infiltrated with the molten material.

Abstract: In some examples, a slurry infiltration fixture. The infiltration fixture includes a fixture main body that includes a slurry introduction channel and a plurality of fixture walls defining a cavity configured to receive a porous component. The cavity includes a component volume and a reservoir volume. The plurality of fixture walls includes a shape configured to define a fixed offset between the porous component and the plurality of fixture walls and a fixed volume for slurry between the plurality of fixture walls and the porous component. The slurry introduction channel is configured introduce the slurry into the cavity through an opening proximate a bottom of the cavity.

Abstract: A method to produce a ceramic matrix composite part, wherein the method comprises providing a ceramic fiber preform. Wherein the ceramic fiber preform includes a three-dimensional framework of a plurality of ceramic fibers. The method comprising, prior to melt infiltration, adding a layer of machinable stock to a target area of the ceramic fiber preform, melt infiltrating the ceramic fiber preform, forming the ceramic matrix composite part by cooling the melt infiltrated ceramic fiber preform, and machining the part in the target area where the machinable stock is located.

Abstract: A method to produce a ceramic matrix composite part, wherein the method comprises providing a ceramic fiber preform. Wherein the ceramic fiber preform includes a three-dimensional framework of a plurality of ceramic fibers. The method comprising, prior to melt infiltration, adding a layer of machinable stock to a target area of the ceramic fiber preform, melt infiltrating the ceramic fiber preform, forming the ceramic matrix composite part by cooling the melt infiltrated ceramic fiber preform, and machining the part in the target area where the machinable stock is located.

Abstract: A method to produce a ceramic matrix composite with controlled surface characteristics includes: applying a scrim ply to a surface of a fiber preform, where the fiber preform includes silicon carbide fibers coated with boron nitride; infiltrating the fiber preform and the scrim ply with a slurry, thereby forming an impregnated ply on an impregnated fiber preform; infiltrating the impregnated fiber preform and the impregnated ply with a melt comprising silicon, and then cooling, thereby forming a ceramic matrix composite having a ceramic surface layer thereon, where the ceramic surface layer has a predetermined thickness and is devoid of boron; machining or grit blasting the ceramic surface layer to form an intermediate layer suitable for coating; and depositing an environmental barrier coating on the intermediate layer. Thus, a ceramic matrix composite coated with the environmental barrier coating is formed with the intermediate layer in between.

Abstract: A method of forming a bladder cast ceramic matrix composite (CMC) article including infiltrating a CMC substrate positioned in a cavity of a mold body with a slurry. The CMC substrate includes reinforcement material defining inner spaces. The slurry includes solid particles and a carrier material. During infiltration, the slurry at least partially fills at least a portion of the inner spaces of the CMC substrate. The method also includes inflating at least one bladder that is coupled to the mold body and disposed within the cavity such that a surface of the at least one bladder in an inflated configuration contacts at least one surface of the CMC substrate. The method also includes drying the slurry to remove at least a portion of the carrier material form an infiltrated CMC and deflating the at least one bladder.

Abstract: A turbine shroud assembly for use with a gas turbine engine includes a turbine outer case, a blade track segment, and a carrier. The turbine outer case is arranged circumferentially around an axis. The blade track segment includes an arcuate runner that extends circumferentially partway around the axis to define a gas path boundary of the turbine shroud assembly and an attachment feature that extends radially outward from the runner. The carrier is configured to couple the blade track segment to the turbine outer case.

Abstract: A method to produce a ceramic matrix composite with controlled surface characteristics includes: applying a scrim ply to a surface of a fiber preform, where the fiber preform includes silicon carbide fibers coated with boron nitride; infiltrating the fiber preform and the scrim ply with a slurry, thereby forming an impregnated ply on an impregnated fiber preform; infiltrating the impregnated fiber preform and the impregnated ply with a melt comprising silicon, and then cooling, thereby forming a ceramic matrix composite having a ceramic surface layer thereon, where the ceramic surface layer has a predetermined thickness and is devoid of boron; machining or grit blasting the ceramic surface layer to form an intermediate layer suitable for coating; and depositing an environmental barrier coating on the intermediate layer. Thus, a ceramic matrix composite coated with the environmental barrier coating is formed with the intermediate layer in between.

Abstract: A turbine shroud assembly for use with a gas turbine engine includes a turbine outer case, a blade track segment, and a carrier. The turbine outer case is arranged circumferentially around an axis. The blade track segment includes an arcuate runner that extends circumferentially partway around the axis to define a gas path boundary of the turbine shroud assembly and an attachment feature that extends radially outward from the runner. The carrier is configured to couple the blade track segment to the turbine outer case.

Abstract: A turbine shroud assembly for use with a gas turbine engine includes a turbine outer case, a blade track segment, and a carrier assembly. The turbine outer case is arranged around an axis. The blade track segment is configured to define a portion of a gas path of the gas turbine engine. The carrier assembly is coupled to the turbine outer case and supports the blade track segment.

Abstract: A system for controlling the clearance distance between an impeller blade tip of a centrifugal compressor and a radially inner surface of an impeller shroud in a turbine engine. The system comprises a high pressure air source, an air piston mounted between an engine casing and the shroud and adapted to receive high pressure air from the high pressure air source, a mounting arm coupling the shroud and air piston, and a slidable coupling adapted to allow axial movement of the shroud and joining the shroud to an axial member.

Abstract: A ceramic matrix composite (CMC) component is provided that includes: a CMC body in which an environmental protection layer is completely embedded within a CMC material of the CMC body, the environmental protection layer comprising a ceramic that has a higher impact and/or environmental resistance than the CMC material. Methods for manufacturing the CMC component are also provided.

Abstract: A system for controlling the clearance distance between an impeller blade tip of a centrifugal compressor and a radially inner surface of an impeller shroud in a turbine engine. The system comprises a high pressure air source, an air piston mounted between an engine casing and the shroud and adapted to receive high pressure air from the high pressure air source, a mounting arm coupling the shroud and air piston, and a slidable coupling adapted to allow axial movement of the shroud and joining the shroud to an axial member.

Abstract: A system for controlling the clearance distance between an impeller blade tip of a centrifugal compressor and a radially inner surface of an impeller shroud in a turbine engine. The system comprises a high pressure air source, an air piston mounted between an engine casing and the shroud and adapted to receive high pressure air from the high pressure air source, a mounting arm coupling the shroud and air piston, and a slidable coupling adapted to allow axial movement of the shroud and joining the shroud to an axial member.

Abstract: A system for controlling the clearance distance between an impeller blade tip of a centrifugal compressor and a radially inner surface of an impeller shroud in a turbine engine. The system comprises a high pressure air source, an air piston mounted between an engine casing and the shroud and adapted to receive high pressure air from the high pressure air source, a mounting arm coupling the shroud and air piston, and a slidable coupling adapted to allow axial movement of the shroud and joining the shroud to an axial member.

Abstract: A system for controlling the clearance distance between an impeller blade tip of a centrifugal compressor and a radially inner surface of an impeller shroud in a turbine engine. The system comprises a high pressure air source, an air piston mounted between an engine casing and the shroud and adapted to receive high pressure air from the high pressure air source, a mounting arm coupling the shroud and air piston, and a slidable coupling adapted to allow axial movement of the shroud and joining the shroud to an axial member.

Abstract: A system for controlling the clearance distance between an impeller blade tip of a centrifugal compressor and a radially inner surface of an impeller shroud in a turbine engine. The system comprises a high pressure air source, an air piston mounted between an engine casing and the shroud and adapted to receive high pressure air from the high pressure air source, a mounting arm coupling the shroud and air piston, and a slidable coupling adapted to allow axial movement of the shroud and joining the shroud to an axial member.