Abstract: In some examples, a method including depositing a plurality of particles on a ceramic or ceramic matrix composite (CMC) substrate to form a barrier coating on the ceramic or CMC substrate, the plurality of particles including a silica-rich rare earth (RE) disilicate material and a second material, wherein the silica-rich RE disilicate material includes excess silica compared to a stoichiometric RE disilicate material, wherein the barrier coating includes a first domain including the silica-rich RE disilicate material and a second phase, the second phase being disposed at grain boundaries, splat boundaries, or both of the barrier coating.

Abstract: A radial turbine rotor incorporating ceramic matrix composite turbine blades is disclosed. The radial turbine rotor can include an axially-extending lug features for coupling the ceramic matrix composite turbine blades to a central hub.

Abstract: A radial turbine rotor incorporating ceramic matrix composite turbine blades is disclosed. The radial turbine rotor can include a dovetail shape retention features for coupling the ceramic matrix composite turbine blades to a central hub.

Abstract: A radial turbine rotor incorporating ceramic matrix composite turbine blades is disclosed. The radial turbine rotor can include a dovetail shape retention features for coupling the ceramic matrix composite turbine blades to a central hub.

Abstract: An article may include a substrate, such as a silicon-containing ceramic matrix composite, an environmental barrier coating (EBC) layer on the substrate, and a CMAS-resistant EBC layer on the EBC layer. The EBC layer may include at least one rare-earth disilicate (REDS). The CMAS-resistant EBC layer may include at least one rare-earth monosilicate (REMS) configured to react with CMAS to form crystalline reaction products. The CMAS-resistant EBC layer may include a plurality of vertical cracks extending from a surface of the CMAS-resistant EBC layer at least partially into the CMAS-resistant EBC layer. Additionally, or alternatively, the EBC layer may include a plurality of vertical cracks extending from a surface of the EBC layer into at least a portion of the EBC layer.

Abstract: A multi-piece radial turbine rotor includes a hub, turbine blades, and an intermediate ring that couples the turbine blades to the hub. Joints between the components of the rotor are adapted for inspection during manufacture to identify potential defects in the joints.

Abstract: A multi-piece radial turbine rotor includes a hub, turbine blades, and a flowpath ring that couples the turbine blades to the hub. Joints between the components of the rotor are adapted for inspection during manufacture to identify potential defects in the joints.

Abstract: The disclosure describes example techniques and assemblies for joining a first component and a second component. The techniques may include positioning the first and second component adjacent to each other to define a joint region between adjacent portions of the first component and the second component, the joint region being coated with an adhesion resistant coating. The techniques may also include positioning a braze material in the joint region, heating the braze material to form an at least softened material, and cooling the at least softened material to form a mechanical interlock including the braze material in the joint region joining the first and second components. The braze material does not metallurgically bond to the joint surface.

Abstract: A method for forming a component for a gas turbine engine may include forming a first portion of the component that includes a cast metal or metal alloy, forming a second portion of the component that includes presintered preform defining at least one support structure, positioning the second portion on the first portion to define an assembly such that the first portion and the second portion define at least one cooling channel therebetween, and heating the assembly to join the first portion and the second portion and form the component.

Abstract: The disclosure describes example techniques and assemblies for joining a first component and a second component. The techniques may include positioning the first and second component adjacent to each other to define a joint region between adjacent portions of the first component and the second component. The techniques may also include inserting a solid retainer material into the joint region through an aperture in one of the first component or the second component to form a mechanical interlock between the first component and the second component and sealing the aperture to retain the solid retainer material within the joint region. The solid retainer material includes at least one of a metal, a metal alloy, or a ceramic.

Abstract: A method for forming a component for a gas turbine engine may include forming a first portion of the component that includes a cast metal or metal alloy, forming a second portion of the component that includes presintered preform defining at least one support structure, positioning the second portion on the first portion to define an assembly such that the first portion and the second portion define at least one cooling channel therebetween, and heating the assembly to join the first portion and the second portion and form the component.

Abstract: The disclosure describes example techniques and assemblies for joining a first component and a second component. The techniques may include positioning the first and second component adjacent to each other to define a joint region between adjacent portions of the first component and the second component, the joint region being coated with an adhesion resistant coating. The techniques may also include positioning a braze material in the joint region, heating the braze material to form an at least softened material, and cooling the at least softened material to form a mechanical interlock including the braze material in the joint region joining the first and second components. The braze material does not metallurgically bond to the joint surface.

Abstract: The disclosure describes example techniques and assemblies for joining a first component and a second component. The techniques may include positioning the first and second component adjacent to each other to define a joint region between adjacent portions of the first component and the second component. The techniques may also include inserting a solid retainer material into the joint region through an aperture in one of the first component or the second component to form a mechanical interlock between the first component and the second component and sealing the aperture to retain the solid retainer material within the joint region. The solid retainer material includes at least one of a metal, a metal alloy, or a ceramic.

Abstract: An article may include a substrate, such as a silicon-containing ceramic matrix composite, an environmental barrier coating (EBC) layer on the substrate, and a CMAS-resistant EBC layer on the EBC layer. The EBC layer may include at least one rare-earth disilicate (REDS). The CMAS-resistant EBC layer may include at least one rare-earth monosilicate (REMS) configured to react with CMAS to form crystalline reaction products. The CMAS-resistant EBC layer may include a plurality of vertical cracks extending from a surface of the CMAS-resistant EBC layer at least partially into the CMAS-resistant EBC layer. Additionally, or alternatively, the EBC layer may include a plurality of vertical cracks extending from a surface of the EBC layer into at least a portion of the EBC layer.

Abstract: The disclosure describes example techniques and assemblies for joining a first component and a second component. The techniques may include positioning the first and second component adjacent to each other to define a joint region between adjacent portions of the first component and the second component, the joint region being coated with an adhesion resistant coating. The techniques may also include positioning a braze material in the joint region, heating the braze material to form an at least softened material, and cooling the at least softened material to form a mechanical interlock including the braze material in the joint region joining the first and second components. The braze material does not metallurgically bond to the joint surface.

Abstract: A method may include depositing a sacrificial support material on or adjacent to a build surface. The sacrificial support material may be configured to support a continuous reinforcement material during an additive manufacturing technique. The method also may include extruding the continuous reinforcement material from an additive manufacturing device such that at least a portion of the continuous reinforcement material contacts and is supported by the sacrificial support material; and removing the sacrificial support material to result in a feature defined at least in part by the continuous reinforcement material at the absence of sacrificial support material.

Abstract: In some examples, a method including depositing a plurality of particles on a ceramic or ceramic matrix composite (CMC) substrate to form a barrier coating on the ceramic or CMC substrate, the plurality of particles including a silica-rich rare earth (RE) disilicate material and a second material, wherein the silica-rich RE disilicate material includes excess silica compared to a stoichiometric RE disilicate material, wherein the barrier coating includes a first domain including the silica-rich RE disilicate material and a second phase, the second phase being disposed at grain boundaries, splat boundaries, or both of the barrier coating.

Abstract: The disclosure describes example techniques and assemblies for joining a first component and a second component. The techniques may include positioning the first and second component adjacent to each other to define a joint region between adjacent portions of the first component and the second component. The techniques may also include inserting a solid retainer material into the joint region through an aperture in one of the first component or the second component to form a mechanical interlock between the first component and the second component and sealing the aperture to retain the solid retainer material within the joint region. The solid retainer material includes at least one of a metal, a metal alloy, or a ceramic.

Abstract: A method may include depositing a sacrificial support material on or adjacent to a build surface. The sacrificial support material may be configured to support a continuous reinforcement material during an additive manufacturing technique. The method also may include extruding the continuous reinforcement material from an additive manufacturing device such that at least a portion of the continuous reinforcement material contacts and is supported by the sacrificial support material; and removing the sacrificial support material to result in a feature defined at least in part by the continuous reinforcement material at the absence of sacrificial support material.

Abstract: A method for fabricating a cast component with a cooling channel is provided. The method includes forming a shell mold over a pattern-ceramic matrix composite (CMC) elongated core arrangement to define a cavity in the shell mold. The pattern-CMC elongated core arrangement includes a pattern-forming material with a CMC elongated core disposed therein. The pattern-forming material in the cavity is replaced with metal via a casting process to form the cast component with the CMC elongated core disposed therein defining the cooling channel. The CMC elongated core is removed from the cast component to open the cooling channel for fluid communication.