Abstract: According to a method set forth herein a plurality of preform plies having first and second preform plies can be associated together to define a preform. The preform can be subject to chemical vapor infiltration (CVI) processing to define a ceramic matrix composite (CMC) structure.

Abstract: According to a method set forth herein a plurality of preform plies having first and second preform plies can be associated together to define a preform. The preform can be subject to chemical vapor infiltration (CVI) processing to define a ceramic matrix composite (CMC) structure.

Abstract: A ceramic matrix composite article includes a melt infiltration ceramic matrix composite substrate comprising a ceramic fiber reinforcement material in a ceramic matrix material having a free silicon proportion, and a chemical vapor infiltration ceramic matrix composite outer layer comprising a ceramic fiber reinforcement material in a ceramic matrix material having essentially no free silicon proportion disposed on an outer surface of at least a portion of the substrate.

Abstract: Provided is a method including obtaining ceramic matrix composite (CMC) with a first matrix portion including a silicon carbide and silicon phase dispersed therewithin, disposing a coating thereupon to form a sealed part, and forming thereupon another segment comprising a CMC, which may be another matrix portion including a silicon carbide and a silicon phase dispersed within therewithin. Also provided is a gas turbine component with a CMC segment including a matrix portion including a silicon carbide and a silicon phase dispersed therewithin, a sealing layer including silicon carbide enclosing the first segment, and a second segment on the sealing layer, wherein the second segment includes a melt-infiltrated CMC having a matrix portion including a silicon carbide and a silicon phase dispersed therewithin.

Abstract: The present disclosure relates to ceramic matrix composites made by chemical vapor infiltration, methods of making the ceramic matrix composites, and ceramic matrix composite turbine components for use in a hot gas pathway. A method of fabricating a ceramic matrix composite is provided that can include the steps of: (i) forming a plurality of holes in a ceramic matrix composite preform of desired shape; and (ii) densifying the preform by a chemical vapor infiltration process to form a part or most of the matrix. A ceramic matrix composite is also provided that can be used in hot combustion gases made according to the aforementioned ceramic matrix composite fabrication method described herein.

Abstract: Provided is a method including obtaining ceramic matrix composite (CMC) with a first matrix portion including a silicon carbide and silicon phase dispersed therewithin, disposing a coating thereupon to form a sealed part, and forming thereupon another segment comprising a CMC, which may be another matrix portion including a silicon carbide and a silicon phase dispersed within therewithin. Also provided is a gas turbine component with a CMC segment including a matrix portion including a silicon carbide and a silicon phase dispersed therewithin, a sealing layer including silicon carbide enclosing the first segment, and a second segment on the sealing layer, wherein the second segment includes a melt-infiltrated CMC having a matrix portion including a silicon carbide and a silicon phase dispersed therewithin.

Abstract: Ceramic matrix composite articles include, for example, a plurality of unidirectional arrays of fiber tows in a matrix having a monomodal pore size distribution, and a fiber volume fraction between about 15 percent and about 35 percent. The articles may be formed by, for example, providing a shaped preform comprising a prepreg tape layup of unidirectional arrays of fiber tows, a matrix precursor, and a pore former, curing the shaped preform to pyrolyze the matrix precursor and burnout the pore former so that the shaped preform comprises the unidirectional arrays of fiber tows and a porous matrix having a monomodal pore size distribution, and subjecting the cured shaped preform to chemical vapor infiltration to densify the porous matrix so that the ceramic matrix composite article has a fiber volume fraction between about 15 percent and about 35 percent.

Abstract: A preform CMC article is disclosed comprising an interior ply structure having at least one interior CMC ply including at least one longitudinal CMC ply disposed along the article length, an exterior shell ply forming an article surface and having at least one exterior CMC ply substantially surrounding the interior ply structure, and at least one wicking portion in which the interior ply structure penetrates the exterior ply shell with an exposed edge of the longitudinal CMC ply disposed at the article surface. A CMC article is disclosed including the interior ply structure and the exterior ply shell, wherein the longitudinal CMC ply includes an exposed edge disposed at the surface of the CMC article. A method for forming the CMC article is disclosed including wicking a melt infiltration agent into the article through the wicking portion into the interior ply structure along the longitudinal CMC ply.

Abstract: The present application provides methods and apparatus for processing ceramic fibers for the manufacture of ceramic matrix composites (CMCs). One method may include providing at least one frame including a planar array of unidirectional ceramic fibers extending across a void thereof. The method may further include depositing a coating on the ceramic fibers of the at least one frame via a chemical vapor deposition (CVD) process. The method may also include impregnating the coated ceramic fibers with a slurry including a ceramic matrix precursor composition to form at least one CMC prepreg, such as a prepreg tape. The ceramic fibers may be substantially SiC fibers, for example.

Abstract: A ceramic matrix composite article includes a melt infiltration ceramic matrix composite substrate comprising a ceramic fiber reinforcement material in a ceramic matrix material having a free silicon proportion, and a chemical vapor infiltration ceramic matrix composite outer layer comprising a ceramic fiber reinforcement material in a ceramic matrix material having essentially no free silicon proportion disposed on an outer surface of at least a portion of the substrate.

Abstract: A method for making a composite material includes disposing a quantity of liquid comprising at least 90 weight percent molten boron within pores of a porous preform, the preform comprising a preform material; and reacting at least a portion of the molten boron with a portion of the preform material to form a solid ceramic reaction product, thereby forming a ceramic matrix composite material. An article comprises a composite material; the composite material comprises a fibrous phase disposed within a matrix. The matrix comprises silicon carbide, boron carbide, and boron silicide.

Abstract: A method for forming a ceramic matrix composite article includes forming by melt infiltration a ceramic matrix composite substrate inducing a ceramic fiber reinforcement material in a ceramic matrix material having a free silicon proportion and forming by chemical vapor infiltration a ceramic matrix composite outer layer including a ceramic fiber reinforcement material in a ceramic matrix material having no free silicon proportion disposed on at least a portion of the substrate.

Abstract: The present application provides methods and apparatus for processing ceramic fibers for the manufacture of ceramic matrix composites (CMCs). One method may include providing at least one frame including a planar array of unidirectional ceramic fibers extending across a void thereof. The method may further include at least one of depositing a coating on the ceramic fibers of the at least one frame via a chemical vapor deposition (CVD) process and impregnating the ceramic fibers with a slurry including a ceramic matrix precursor composition to form at least one CMC prepreg. In some embodiments, the ceramic fibers of the planar array may include a coating, and the method may include impregnating the coated ceramic fibers with a slurry including a ceramic matrix precursor composition to form at least one CMC prepreg.

Abstract: A preform CMC article is disclosed comprising an interior ply structure having at least one interior CMC ply including at least one longitudinal CMC ply disposed along the article length, an exterior shell ply forming an article surface and having at least one exterior CMC ply substantially surrounding the interior ply structure, and at least one wicking portion in which the interior ply structure penetrates the exterior ply shell with an exposed edge of the longitudinal CMC ply disposed at the article surface. A CMC article is disclosed including the interior ply structure and the exterior ply shell, wherein the longitudinal CMC ply includes an exposed edge disposed at the surface of the CMC article. A method for forming the CMC article is disclosed including wicking a melt infiltration agent into the article through the wicking portion into the interior ply structure along the longitudinal CMC ply.

Abstract: A method can include applying a mask to a CMC structure, and subjecting the structure having an applied mask to a process for repair. In one embodiment, the applying a mask to a CMC structure can include applying a mask to a feature of a CMC structure.

Abstract: A method for making a composite material includes disposing a quantity of liquid comprising at least 90 weight percent molten boron within pores of a porous preform, the preform comprising a preform material; and reacting at least a portion of the molten boron with a portion of the preform material to form a solid ceramic reaction product, thereby forming a ceramic matrix composite material. An article comprises a composite material; the composite material comprises a fibrous phase disposed within a matrix. The matrix comprises silicon carbide, boron carbide, and boron silicide.

Abstract: Ceramic matrix composite articles include, for example, a plurality of unidirectional arrays of fiber tows in a matrix having a monomodal pore size distribution, and a fiber volume fraction between about 15 percent and about 35 percent. The articles may be formed by, for example, providing a shaped preform comprising a prepreg tape layup of unidirectional arrays of fiber tows, a matrix precursor, and a pore former, curing the shaped preform to pyrolyze the matrix precursor and burnout the pore former so that the shaped preform comprises the unidirectional arrays of fiber tows and a porous matrix having a monomodal pore size distribution, and subjecting the cured shaped preform to chemical vapor infiltration to densify the porous matrix so that the ceramic matrix composite article has a fiber volume fraction between about 15 percent and about 35 percent.

Abstract: Provided is a method including obtaining ceramic matrix composite (CMC) with a first matrix portion including a silicon carbide and silicon phase dispersed therewithin, disposing a coating thereupon to form a sealed part, and forming thereupon another segment comprising a CMC, which may be another matrix portion including a silicon carbide and a silicon phase dispersed within therewithin. Also provided is a gas turbine component with a CMC segment including a matrix portion including a silicon carbide and a silicon phase dispersed therewithin, a sealing layer including silicon carbide enclosing the first segment, and a second segment on the sealing layer, wherein the second segment includes a melt-infiltrated CMC having a matrix portion including a silicon carbide and a silicon phase dispersed therewithin.

Abstract: The present application provides methods and apparatus for processing ceramic fibers for the manufacture of ceramic matrix composites (CMCs). One method may include providing at least one frame including a planar array of unidirectional ceramic fibers extending across a void thereof. The method may further include depositing a coating on the ceramic fibers of the at least one frame via a chemical vapor deposition (CVD) process. The method may also include impregnating the coated ceramic fibers with a slurry including a ceramic matrix precursor composition to form at least one CMC prepreg, such as a prepreg tape. The ceramic fibers may be substantially SiC fibers, for example.

Abstract: Ceramic matrix composite articles include, for example, a plurality of unidirectional arrays of fiber tows in a matrix having a monomodal pore size distribution, and a fiber volume fraction between about 15 percent and about 35 percent. The articles may be formed by, for example, providing a shaped preform comprising a prepreg tape layup of unidirectional arrays of fiber tows, a matrix precursor, and a pore former, curing the shaped preform to pyrolyze the matrix precursor and burnout the pore former so that the shaped preform comprises the unidirectional arrays of fiber tows and a porous matrix having a monomodal pore size distribution, and subjecting the cured shaped preform to chemical vapor infiltration to densify the porous matrix so that the ceramic matrix composite article has a fiber volume fraction between about 15 percent and about 35 percent.