Abstract: A three-dimensional preform, composite components formed with the preform, and processes for producing the preform and composite materials. The three-dimensional preform includes first and second sets of tows containing filaments. Each tow of the first set has a predetermined polygonal cross-sectional shape and is embedded within a temporary matrix. The preform is fabricated from the first and second sets of tows, in which the second set of tows are transverse to the first set of tows, adjacent tows of the second set are spaced apart to define interstitial regions therebetween, and the polygonal cross-sectional shapes of the first set of tows are substantially congruent to the cross-sectional shapes of the interstitial regions so as to substantially fill the interstitial regions.

Abstract: A preform architecture and process for producing composite materials, and particularly CMC components. The process entails producing a composite component having a matrix material reinforced with a three-dimensional preform. The process includes producing first and second sets of tows containing filaments. Each tow of the first set has a predetermined cross-sectional shape and is embedded within a temporary matrix material formed of a material that is not the matrix material or a precursor of the matrix material. The preform is then fabricated from the first and second sets of tows, in which the second set of tows are transverse to the first set of tows, adjacent tows of the second set are spaced apart to define interstitial regions therebetween, and the cross-sectional shapes of the first set of tows are substantially congruent to the cross-sectional shapes of the interstitial regions so as to substantially fill the interstitial regions.

Abstract: A method of manufacturing a turbine engine component is disclosed. The method includes the steps of providing a plurality of ceramic cloth plies, each ply having woven ceramic fiber tows and at least one fugitive fiber tow, laying up the plurality of plies in a preselected arrangement to form a turbine engine component shape, oxidizing the fugitive fibers to produce fugitive fiber void regions in the ply, rigidizing the component shape to form a coated component preform using chemical vapor infiltration, partially densifying the coated component preform using carbon-containing slurry, and further densifying the coated component preform with at least silicon to form a ceramic matrix composite turbine engine component having matrix rich regions.

Abstract: A ceramic matrix composite (CMC) component for gas turbine engines, the component having fine features such as thin edges with thicknesses of less than about 0.030 inches and small radii of less that about 0.030 inches formed using the combination of prepreg plies layed up with non-ply ceramic inserts. The CMC components of the present invention replace small ply inserts cut to size to fit into areas of contour change or thickness change, and replace the small ply inserts with a fabricated single piece discontinuously reinforced composite insert, resulting in fewer defects, such as wrinkles, and better dimensional control.

Abstract: A ceramic matrix composite with a ceramic matrix and a gradient layering of coating on ceramic fibers. The coating typically improves the performance of the composite in one direction while degrading it in another direction. For a SiC-SiC ceramic matrix composite, a BN coating is layered in a gradient fashion or in a step-wise fashion in different regions of the article comprising the ceramic. The BN coating thickness is applied over the ceramic fibers to produce varying desired physical properties by varying the coating thickness within differing regions of the composite, thereby tailoring the strength of the composite in the different regions. The coating may be applied as a single layer as a multi-layer coating to enhance the performance of the coating as the ceramic matrix is formed or infiltrated from precursor materials into a preform of the ceramic fibers.

Abstract: A ceramic matrix composite (CMC) component for gas turbine engines, the component having fine features such as thin edges with thicknesses of less than about 0.030 inches and small radii of less that about 0.030 inches formed using the combination of prepreg plies layed up with non-ply ceramic inserts. The CMC components of the present invention replace small ply inserts cut to size to fit into areas of contour change or thickness change, and replace the small ply inserts with a fabricated single piece discontinuously reinforced composite insert, resulting in fewer defects, such as wrinkles, and better dimensional control.

Abstract: A ceramic matrix composite with a ceramic matrix and a gradient layering of coating on ceramic fibers. The coating typically improves the performance of the composite in one direction while degrading it in another direction. For a SiC-SiC ceramic matrix composite, a BN coating is layered in a gradient fashion or in a step-wise fashion in different regions of the article comprising the ceramic. The BN coating thickness is applied over the ceramic fibers to produce varying desired physical properties by varying the coating thickness within differing regions of the composite, thereby tailoring the strength of the composite in the different regions. The coating may be applied as a single layer as a multi-layer coating to enhance the performance of the coating as the ceramic matrix is formed or infiltrated from precursor materials into a preform of the ceramic fibers.

Abstract: The present invention is a ceramic matrix composite turbine engine component, wherein the component has a direction of maximum tensile stress during normal engine operation. The component comprises a plurality of biased ceramic plies, wherein each biased ply comprises ceramic fiber tows, the tows being woven in a first warp direction and a second weft direction, the second weft direction lying at a preselected angular orientation with respect to the first warp direction, wherein a greater number of tows are woven in the first warp direction than in the second weft direction, and wherein a number of tows in the second weft direction allows the biased plies to maintain their structural integrity when handled.

Abstract: A method for forming a ceramic matrix composite (CMC) component for gas turbine engines. The method contemplates replacing a plurality of plies with insert material. The insert material can be partially cured or pre-cured and applied in place of a plurality of small plies or it may be inserted into cavities of a component in the form of a paste or a ply. The insert material is isotropic, being formed of a combination of matrix material and chopped fibers, tow, cut plies or combinations thereof. The use of the insert material allows for features such as thin edges with thicknesses of less than about 0.030 inches and small radii such as found in corners. The CMC components of the present invention replace small ply inserts cut to size to fit into areas of contour change or thickness change, and replace the small ply inserts with a fabricated single piece discontinuously reinforced composite insert, resulting in fewer defects, such as wrinkles, and better dimensional control.

Abstract: Methods for making tape cast barrier coatings involving making a slurry including at least a solvent and a barrier coating composition, depositing the slurry onto a carrier film in a tape casting machine to produce a cast slurry, evaporating the solvent from the cast slurry to produce a tape including the carrier film, and the barrier coating composition, and removing the carrier film from the tape to produce a tape cast barrier coating.

Abstract: Tapes including a carrier film, and at least one barrier coating composition applied to the carrier film where the barrier coating composition is an environmental barrier coating composition or a thermal barrier coating composition.

Abstract: Methods for repairing barrier coatings involving providing a component having a barrier coating including at least one damaged portion, removing the damaged portion of the barrier coating leaving a void, applying a replacement tape cast barrier coating to the void of the component, and sintering the component having the replacement tape cast barrier coating layer.

Abstract: A method of manufacturing a turbine engine component comprising the steps of providing and laying up a plurality of ceramic plies comprising woven ceramic fiber tows to form a turbine engine component shape, inserting a plurality of tows of oxidizable fugitive fibers into the component shape, such that each fugitive fiber tow passes through a preselected number of ceramic plies, burning off the fugitive fiber tows, the burning producing through-thickness void regions, rigidizing the component shape with a layer of BN and a layer of SiC to form a coated component preform using chemical vapor infiltration, and partially densifying the coated component preform using carbon-containing slurry and filling the through thickness void regions, and further densifying the coated component preform with at least silicon to form a ceramic matrix composite turbine engine component with in-situ ceramic matrix plugs formed where the through-thickness void regions were located.

Abstract: A metallic alloy having at least two metallic constituents is produced by first furnishing at least two non-oxide compounds, wherein the non-oxide compounds collectively comprise each of the metallic constituents, and wherein each of the non-oxide compounds is soluble in a mutual solvent. The method further includes dissolving the non-oxide compounds in the mutual solvent to produce a solution containing the metallic constituents, thereafter heating the solution to remove the mutual solvent and oxidize the metallic constituents to produce a mixed metallic oxide, thereafter cooling the mixed metallic oxide to form a substantially homogeneous mixed metallic oxide solid mass, and thereafter chemically reducing the mixed metallic oxide solid mass to produce a metallic alloy. The metallic alloy may be consolidated or otherwise processed.

Abstract: A preform architecture and process for producing composite materials, and particularly CMC components. The process entails producing a composite component having a matrix material reinforced with a three-dimensional preform. The process includes producing first and second sets of tows containing filaments. Each tow of the first set has a predetermined cross-sectional shape and is embedded within a temporary matrix material formed of a material that is not the matrix material or a precursor of the matrix material. The preform is then fabricated from the first and second sets of tows, in which the second set of tows are transverse to the first set of tows, adjacent tows of the second set are spaced apart to define interstitial regions therebetween, and the cross-sectional shapes of the first set of tows are substantially congruent to the cross-sectional shapes of the interstitial regions so as to substantially fill the interstitial regions.

Abstract: A ceramic matrix composite (CMC) component for gas turbine engines, the component having fine features such as thin edges with thicknesses of less than about 0.030 inches and small radii of less that about 0.030 inches formed using the combination of prepreg plies layed up with non-ply ceramic inserts. The CMC components of the present invention replace small ply inserts cut to size to fit into areas of contour change or thickness change, and replace the small ply inserts with a fabricated single piece discontinuously reinforced composite insert, resulting in fewer defects, such as wrinkles, and better dimensional control.

Abstract: A method for making a ceramic matrix composite turbine engine component, wherein the method includes providing a plurality of biased ceramic plies, wherein each biased ply comprises ceramic fiber tows, the tows being woven in a first warp direction and a second weft direction, the second weft direction lying at a preselected angular orientation with respect to the first warp direction, wherein a greater number of tows are woven in the first warp direction than in the second weft direction. The plurality of biased plies are laid up in a preselected arrangement to form the component, and a preselected number of the plurality of biased plies are oriented such that the orientation of the first warp direction of the plies lie about in the direction of maximum tensile stress during normal engine operation. A coating is applied to the plurality of biased plies. The coated component preform is then densified.

Abstract: The present invention is a ceramic matrix composite turbine engine component, wherein the component has a region of expected higher interlaminate stress during normal engine operation. The component includes both coated fiber tows and uncoated fiber tows arranged together into a preselected form, wherein the uncoated fiber tows are located at predetermined regions of expected high interlaminate stress. The invention further includes method of manufacturing a CMC such as a composite turbine engine component, wherein the component has a region of expected higher interlaminate stress during engine operation.

Abstract: Process for fabricating a preform, wherein a fiber preform is infiltrated with molten silicon after being contacted with an aqueous silicon carbide particulate slurry containing a dissolved source of carbon and heated to coat the particles with carbon.

Abstract: A metallic alloy having at least two metallic constituents is produced by first furnishing at least two non-oxide compounds, wherein the non-oxide compounds collectively comprise each of the metallic constituents, and wherein each of the non-oxide compounds is soluble in a mutual solvent. The method further includes dissolving the non-oxide compounds in the mutual solvent to produce a solution containing the metallic constituents, thereafter heating the solution to remove the mutual solvent and oxidize the metallic constituents to produce a mixed metallic oxide, thereafter cooling the mixed metallic oxide to form a substantially homogeneous mixed metallic oxide solid mass, and thereafter chemically reducing the mixed metallic oxide solid mass to produce a metallic alloy. The metallic alloy may be consolidated or otherwise processed.