Abstract: A system and method for forming a porous ceramic preform is provided. The method may include forming a stacked powder structure including a binder layer and a powder layer on the binder layer. The binder layer may be formed by depositing a binder with a spray nozzle on a substrate. The powder layer may be formed by depositing a powder on the binder layer. The porous ceramic preform may be formed by heating the stacked powder structure to pyrolyze the binder. The porous ceramic preform is configured to be infiltrated by a molten material. The substrate may comprise a ceramic fiber preform. After melt infiltration of the porous ceramic preform and the ceramic fiber preform, a densified ceramic feature having a predetermined geometry may be formed on a ceramic matrix composite (CMC) component.

Abstract: A system and method for forming a ceramic matrix composite blade track is provided. The method may include stacking a plurality of first plies to form a first porous preform layer, the first plies including a plurality of first ceramic fibers. The method may further include stacking a plurality of second plies to form a second porous preform layer, the second plies including a plurality of second ceramic fibers. The method may further include combining the first porous preform layer and the second porous preform layer to form a unified porous preform. The method may further include forming a structural layer by infiltrating the first porous preform with a first ceramic matrix material, and forming an abradable layer by infiltrating the second porous preform with a second ceramic matrix material.

Abstract: A braze alloy for joining or repairing ceramic matrix composite (CMC) components comprises a braze composition including silicon at a concentration from about 48 at. % to about 66 at. %, titanium at a concentration from about 1 at. % to about 35 at. %, and an additional element selected from aluminum, cobalt, vanadium, nickel, and chromium. The braze composition comprises a melting temperature of less than 1300° C.

Abstract: A system and method for forming a ceramic matrix composite blade track is provided. The method may include stacking a plurality of first plies to form a first porous preform layer, the first plies including a plurality of first ceramic fibers. The method may further include stacking a plurality of second plies to form a second porous preform layer, the second plies including a plurality of second ceramic fibers. The method may further include combining the first porous preform layer and the second porous preform layer to form a unified porous preform. The method may further include forming a structural layer by infiltrating the first porous preform with a first ceramic matrix material, and forming an abradable layer by infiltrating the second porous preform with a second ceramic matrix material.

Abstract: An airfoil and a method of manufacturing an airfoil may be provided, where the airfoil comprises a core and a shell. The core comprises core ceramic fibers extending along a span of the airfoil. The shell surrounds the core and includes shell ceramic fibers. Substantially all of the core ceramic fibers are arranged in a radial direction. The airfoil may also be a ceramic matrix composite formed by infiltrating the core and the shell with a matrix material.

Abstract: A system and method for forming a porous ceramic preform is provided. The method may include forming a stacked powder structure including a binder layer and a powder layer on the binder layer. The binder layer may be formed by depositing a binder with a spray nozzle on a substrate. The powder layer may be formed by depositing a powder on the binder layer. The porous ceramic preform may be formed by heating the stacked powder structure to pyrolyze the binder. The porous ceramic preform is configured to be infiltrated by a molten material. The substrate may comprise a ceramic fiber preform. After melt infiltration of the porous ceramic preform and the ceramic fiber preform, a densified ceramic feature having a predetermined geometry may be formed on a ceramic matrix composite (CMC) component.

Abstract: A braze alloy for joining or repairing ceramic matrix composite (CMC) components comprises a braze composition including silicon at a concentration from about 48 at. % to about 66 at. %, titanium at a concentration from about 1 at. % to about 35 at. %, and an additional element selected from aluminum, cobalt, vanadium, nickel, and chromium. The braze composition comprises a melting temperature of less than 1300° C.

Abstract: A dual-walled ceramic matrix composite (CMC) component comprises: a CMC core having a hollow shape enclosing at least one interior channel; and a CMC outer layer overlying and spaced apart from the CMC core by a ceramic slurry-cast architecture positioned therebetween. Each of the CMC core and the CMC outer layer comprises ceramic fibers in a ceramic matrix. The CMC core further includes a plurality of through-thickness inner cooling holes in fluid communication with the at least one interior channel. The ceramic slurry-cast architecture defines a cooling fluid path over an outer surface of the CMC core that connects the interior channel(s) to an external environment of the dual-walled CMC component. The CMC outer layer may also include a plurality of through-thickness outer cooling holes in fluid communication with the cooling fluid path, thereby extending the cooling fluid path through the CMC outer layer.

Abstract: An airfoil and a method of manufacturing an airfoil may be provided, where the airfoil comprises a core and a shell. The core comprises core ceramic fibers extending along a span of the airfoil. The shell surrounds the core and includes shell ceramic fibers. Substantially all of the core ceramic fibers are arranged in a radial direction. The airfoil may also be a ceramic matrix composite formed by infiltrating the core and the shell with a matrix material.

Abstract: A dual-walled ceramic matrix composite (CMC) component comprises: a CMC core having a hollow shape enclosing at least one interior channel; and a CMC outer layer overlying and spaced apart from the CMC core by a ceramic slurry-cast architecture positioned therebetween. Each of the CMC core and the CMC outer layer comprises ceramic fibers in a ceramic matrix. The CMC core further includes a plurality of through-thickness inner cooling holes in fluid communication with the at least one interior channel. The ceramic slurry-cast architecture defines a cooling fluid path over an outer surface of the CMC core that connects the interior channel(s) to an external environment of the dual-walled CMC component. The CMC outer layer may also include a plurality of through-thickness outer cooling holes in fluid communication with the cooling fluid path, thereby extending the cooling fluid path through the CMC outer layer.

Abstract: A method of producing a ceramic weld, including identifying a ceramic first surface and a ceramic second surface to be bonded together, maintaining a non-oxidizing atmosphere over the first and second surfaces, and engaging the first and second surfaces to define a joint. An arc is generated between an electrode and the joint to create a liquid phase, and the liquid phase is cooled to yield a solid fusion layer, wherein the first and second surfaces are joined in the fusion layer.