Slurry infiltration process

Abstract

A process for fabricating a partially densified ceramic matrix composite, comprising the steps of fabricating a ceramic fiber preform comprising a fiber, a fiber tow, or both; optionally depositing an interface coating on the fiber, the fiber tow, or both; depositing a structural support material on the fiber, the fiber tow, or both to form a partially densified ceramic matrix composite comprising pores, a porous network or both; preparing at least one slurry composition comprising particulate particles; infiltrating the slurry composition into the partially densified ceramic matrix composite and depositing the particulate particles into the pores, the porous network or both; rapidly solidifying one or more liquid phases of the slurry composition within a slurry infiltrated partially densified ceramic matrix composite; drying a solidified slurry infiltrated partially densified ceramic matrix composite.

Description

RTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WOSLURRY INFILTRATION PROCESSCROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of United States Provisional Patent Application No.63 / 749,427 filed on January 24, 2025, which is hereby incorporated by reference for all purposes as if fully set forth herein.FIELD OF THE INVENTION

[0002] The subject matter disclosed herein relates to the slurry infiltration of solid particles and, in particular, to the slurry infiltration of solid particles using a combination of rapid liquid or liquid phases solidification and drying techniques for more uniform distribution.BACKGROUND OF THE INVENTION

[0003] Slurry infiltration processes can employ either thermal drying or freeze-drying techniques to complete the process. Freeze-drying is favored as the technique enhances the uniform distribution of particles and carbon sources within the pores of partially densified ceramic matrix composites. Such uniformity can achieve consistent material properties in the final product.

[0004] However, conventional freeze dryers operate at moderate cooling rates, resulting in a slow freezing process, e.g., of the slurry and solvent in a slurry infiltration processes. During this extended freezing period, coarse particles, or even some fine particles, within the slurry tend to settle due to gravity. Such settling leads to localized variations in particle distribution within the partially densified ceramic matrix composite. Once dried, these localized variations compromise the homogeneity of the particle and carbon source dispersion within the partially densified ceramic matrix composite. The compromised homogeneity potentially affects the quality and performance of the final product. Addressing this limitation is essential to improving the reliability and efficiency of slurry infiltration methods utilizing freeze-drying techniques.RTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WO

[0005] Consequently, there is a need for an improved freeze-drying technique.SUMMARY OF THE INVENTION

[0006] The present disclosure is directed, in a first aspect, to a process for fabricating a partially densified ceramic matrix composite, comprising the steps of: fabricating a ceramic fiber preform comprising at least one fiber, at least one fiber tow, or at least one fiber and fiber tow; optionally depositing an interface coating on the at least one fiber, the at least one fiber tow, or the at least one fiber and fiber tow; depositing a structural support material on the at least one fiber, the at least one fiber tow, or the at least one fiber and fiber tow to form a partially densified ceramic matrix composite comprising at least one pore, at least one porous network or at least one pore and porous network; preparing at least one slurry composition comprising at least one solid particle; infiltrating the slurry composition into the partially densified ceramic matrix composite and depositing the at least one solid particle into the at least one pore, the at least one porous network or the at least one pore and porous network; rapidly solidifying one or more liquid phases of the slurry composition within a slurry infiltrated partially densified ceramic matrix composite; and drying a solidified slurry infiltrated partially densified ceramic matrix composite.

[0007] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, rapidly solidifying comprises the following steps: loading the slurry infiltrated partially densified ceramic matrix composite into an apparatus; charging a liquid cryogenic material into the apparatus; rapidly solidifying the one or more liquid phases of the slurry composition within the slurry infiltrated partially densified ceramic matrix composite; and optionally, applying ultrasound during rapid solidification.

[0008] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, rapidly solidifying comprises the following steps: loading the slurry infiltrated partially densified ceramic matrix composite into an apparatus; charging a liquid cryogenic material into the apparatus; applying a vacuum within the apparatus; rapidly solidifyingRTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WOthe one or more liquid phases of the slurry composition within the slurry infiltrated partially densified ceramic matrix composite; and optionally, applying ultrasound during rapid solidification.

[0009] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, rapidly solidifying comprises the following steps: loading the slurry infiltrated partially densified ceramic matrix composite into an apparatus; applying a vacuum within the apparatus; charging a liquid cryogenic material into the apparatus; rapidly solidifying the one or more liquid phases of the slurry composition within the slurry infiltrated partially densified ceramic matrix composite; and optionally, applying ultrasound during rapid solidification.

[0010] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, rapidly solidifying comprises the following steps: loading the slurry infiltrated partially densified ceramic matrix composite into an apparatus; charging a gaseous cryogenic material into the apparatus; rapidly solidifying the one or more liquid phases of the slurry composition within the slurry infiltrated partially densified ceramic matrix composite; and optionally, applying ultrasound during rapid solidification.

[0011] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, rapidly solidifying comprises the following steps: loading the slurry infiltrated partially densified ceramic matrix composite into an apparatus; spraying a liquid cryogenic material onto the slurry infiltrated partially densified ceramic matrix composite; rapidly solidifying the slurry composition disposed within the slurry infiltrated partially densified ceramic matrix composite; and optionally, applying ultrasound during rapid solidification.

[0012] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, rapidly solidifying comprises the following steps: loading the slurry infiltrated partially densified ceramic matrix composite into an apparatus; charging a slushRTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WOcomprising at least one phase of cryogenic materials into the apparatus; rapidly solidifying one or more liquid phases of the slurry composition within the slurry infiltrated partially densified ceramic matrix composite; and optionally, applying ultrasound during rapid solidification.

[0013] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, the at least one slurry further comprises one or more of the following: a solvent, a binder, a gelling agent, a dispersant, a wetting agent, a pH adjustor, an ice nucleator, a recrystallization inhibitor, and combinations thereof.

[0014] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, the gelling agent, the binders or both the gelling agent and the binders comprise any one or more of the following: polyvinyl alcohol (PVA), polyvinyl butyral (PVB), lignosulfonates, starches aluminosilicate, carboxymethylcellulose, methyl cellulose, carboethyl cellulose, hydroxypropyl methyl cellulose, gellan gum, gelatins, pectin, aragose gum, curdlan gum, xanthium gum, konjac gum, carrageenan gum, alginates, sodium alginate, agar gum, non-ionic copolymer surfactants, and combinations thereof.

[0015] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, the at least one solid particle comprises any one or more of the following materials: carbon source materials, nitride source materials, boride source materials, oxide source materials, oxide phase precursor materials, metal source materials and metalloid source materials.

[0016] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, the carbon source materials comprise any one or more of the following: carbon-based materials, carbide materials, graphite, carbon nanotube, carbon nanofiber, and diamond.

[0017] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, the carbide materials comprise any one or more of theRTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WOfollowing: boron carbides, zirconium carbides, hafnium carbides, tantalum carbides, niobium carbides, titanium carbides, molybdenum carbides, tungsten carbides, vanadium carbides, chromium carbides, ytterbium carbides, and yttrium carbides.

[0018] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, the nitride source materials comprise any one or more of the following: silicon nitrides, titanium nitrides, boron nitrides, zirconium nitrides, hafnium nitrides, niobium nitrides, tantalum nitrides, vanadium nitrides, ytterbium nitrides, and yttrium nitrides.

[0019] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, the boride source materials comprise any one or more of the following: silicon borides, titanium borides, zirconium borides, hafnium borides, niobium borides, tantalum borides, vanadium borides, molybdenum borides, ytterbium borides, and yttrium borides.

[0020] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, the oxide source materials comprise any one or more of the following: aluminum oxides, silicon oxides, tantalum oxides, boron oxides, hafnium oxides, zirconium oxides, ytterbium oxides, and yttrium oxides.

[0021] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, the oxide phase precursor materials comprise one or more of the following: BaOa-SiC ; AEO-ALOa-SiCh, where AE comprises at least one of Be, Ca, Ba and Sr; REO-ALOa-SiCh, where RE comprises at least one of La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y; and, combinations thereof.

[0022] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, depositing comprises one or more of the following techniques: slurry infiltration and chemical vapor infiltration.RTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WO

[0023] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, the interface coating or the structural support material or both the interface coating and the structural support material comprises one or more of the following materials: carbides, carbon materials, nitrides, borides, and combinations thereof.

[0024] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, the carbides comprise one or more of the following: silicon carbides, boron carbides, zirconium carbides, hafnium carbides, tantalum carbides, niobium carbides, titanium carbides, molybdenum carbides, tungsten carbides, vanadium carbides, chromium carbides, ytterbium carbides, yttrium carbides, and combinations thereof.

[0025] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, the carbon materials comprise one or more of the following: pyrolytic carbons, graphite and combinations thereof.

[0026] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, the nitrides comprise one or more of the following: silicon nitrides, titanium nitrides, boron nitrides, zirconium nitrides, hafnium nitrides, niobium nitrides, tantalum nitrides, vanadium nitrides, ytterbium nitrides, yttrium nitrides, and combinations thereof.

[0027] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, the borides comprise one or more of the following: silicon borides, titanium borides, zirconium borides, hafnium borides, niobium borides, tantalum borides, vanadium borides, ytterbium borides, yttrium borides, and combinations thereof.

[0028] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, the apparatus comprises any one or more of the following: a vacuum chamber, a slurry infiltration chamber, a freeze dryer, and combinations thereof.RTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WO

[0029] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, the partially densified ceramic matrix composite further comprises densifying the partially densified ceramic matrix composite using any one or more of the following techniques: melt-infiltration, polymer infiltration and pyrolysis, atomic layer deposition, chemical vapor infiltration, physical vapor deposition, chemical vapor deposition, and combinations thereof.

[0030] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, melt-infiltrating further comprises melt-infiltrating one or more of the following molten infiltrants: metals, metalloids, metal alloys, metalloid alloys, glasses, and combinations thereof.

[0031] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, the partially densified ceramic matrix composite further comprises heat treating a densified ceramic matrix composite.

[0032] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, drying further comprises evaporating one or more liquid phases of the slurry composition within the slurry infiltrated partially densified ceramic matrix composite.

[0033] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, drying further comprises sublimating one or more liquid phases of the slurry composition within the slurry infiltrated partially densified ceramic matrix composite.

[0034] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, drying further comprises subjecting the solidified partially densified ceramic matrix composite at a temperature of at least room temperature to at least one of the following processes: aging, drying, curing, and combinations thereof.RTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WO

[0035] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, aging or drying further comprises at least partially evaporating one or more liquid phases of the slurry composition of the solidified partially densified ceramic matrix composite.

[0036] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, the process further comprises curing at least one remaining binder present in the partially densified ceramic matrix composite.

[0037] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, the process further comprises cross-linking at least one remaining binder present in the partially densified ceramic matrix composite.

[0038] In another embodiment, the present disclosure is directed to a partially densified ceramic matrix composite fabricated by a process comprising the steps of: fabricating a ceramic fiber preform comprising at least one fiber, at least one fiber tow, or at least one fiber and fiber tow; optionally depositing an interface coating on the at least one fiber, the at least one fiber tow, or the at least one fiber and fiber tow; depositing a structural support material on the at least one fiber, the at least one fiber tow, or the at least one fiber and fiber tow to form a partially densified ceramic matrix composite comprising at least one pore, at least one porous network or at least one pore and porous network; preparing at least one slurry composition comprising at least one solid particle; infiltrating the slurry composition into the partially densified ceramic matrix composite and depositing the at least one solid particle into the at least one pore, the at least one porous network or the at least one pore and porous network; rapidly solidifying a slurry infiltrated partially densified ceramic matrix composite; and, drying a solidified slurry infiltrated partially densified ceramic matrix composite.

[0039] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, rapidly solidifying comprises the following steps: loading theRTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WOslurry infiltrated partially densified ceramic matrix composite into an apparatus; charging a liquid cryogenic material into the apparatus; rapidly solidifying the one or more liquid phases of the slurry composition within the slurry infiltrated partially densified ceramic matrix composite; and optionally, applying ultrasound during rapid solidification.

[0040] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, rapidly solidifying comprises the following steps: loading the slurry infiltrated partially densified ceramic matrix composite into an apparatus; charging a liquid cryogenic material into the apparatus; applying a vacuum within the apparatus; rapidly solidifying the one or more liquid phases of the slurry composition within the slurry infiltrated partially densified ceramic matrix composite; and optionally, applying ultrasound during rapid solidification.

[0041] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, rapidly solidifying comprises the following steps: loading the slurry infiltrated partially densified ceramic matrix composite into an apparatus; applying a vacuum within the apparatus; charging a liquid cryogenic material into the apparatus; rapidly solidifying the one or more liquid phases of the slurry composition within the slurry infiltrated partially densified ceramic matrix composite; and optionally, applying ultrasound during rapid solidification.

[0042] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, rapidly solidifying comprises the following steps: loading the slurry infiltrated partially densified ceramic matrix composite into an apparatus; charging a gaseous cryogenic material into the apparatus; rapidly solidifying the one or more liquid phases of the slurry composition within the slurry infiltrated partially densified ceramic matrix composite; and optionally, applying ultrasound during rapid solidification.RTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WO

[0043] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, rapidly solidifying comprises the following steps: loading the slurry infiltrated partially densified ceramic matrix composite into an apparatus; spraying a liquid cryogenic material onto the slurry infiltrated partially densified ceramic matrix composite; rapidly solidifying the slurry composition disposed within the slurry infiltrated partially densified ceramic matrix composite; and optionally, applying ultrasound during rapid solidification.

[0044] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, rapidly solidifying comprises the following steps: loading the slurry infiltrated partially densified ceramic matrix composite into an apparatus; charging a slush comprising at least one phase of cryogenic materials into the apparatus; rapidly solidifying one or more liquid phases of the slurry composition within the slurry infiltrated partially densified ceramic matrix composite; and optionally, applying ultrasound during rapid solidification.

[0045] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, the at least one slurry further comprises one or more of the following: a solvent, a binder, a gelling agent, a dispersant, a wetting agent, a pH adjustor, an ice nucleator, a recrystallization inhibitor, and combinations thereof.

[0046] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, the gelling agent, the binders or both the gelling agent and the binders comprise any one or more of the following: polyvinyl alcohol (PVA), polyvinyl butyral (PVB), lignosulfonates, starches aluminosilicate, carboxymethylcellulose, methyl cellulose, carboethyl cellulose, hydroxypropyl methyl cellulose, gellan gum, gelatins, pectin, aragose gum, curdlan gum, xanthium gum, konjac gum, carrageenan gum, alginates, sodium alginate, agar gum, non-ionic copolymer surfactants, and combinations thereof.

[0047] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, the at least one solid particle comprises any one or more of theRTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WOfollowing materials: carbon source materials, nitride source materials, boride source materials, oxide source materials, oxide phase precursor materials, metal source materials and metalloid source materials.

[0048] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, the carbon source materials comprise any one or more of the following: carbon-based materials, carbide materials, graphite, carbon nanotube, carbon nanofiber, and diamond.

[0049] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, the carbide materials comprise any one or more of the following: boron carbides, zirconium carbides, hafnium carbides, tantalum carbides, niobium carbides, titanium carbides, molybdenum carbides, tungsten carbides, vanadium carbides, chromium carbides, ytterbium carbides, and yttrium carbides.

[0050] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, the nitride source materials comprise any one or more of the following: silicon nitrides, titanium nitrides, boron nitrides, zirconium nitrides, hafnium nitrides, niobium nitrides, tantalum nitrides, vanadium nitrides, ytterbium nitrides, and yttrium nitrides.

[0051] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, the boride source materials comprise any one or more of the following: silicon borides, titanium borides, zirconium borides, hafnium borides, niobium borides, tantalum borides, vanadium borides, molybdenum borides, ytterbium borides, and yttrium borides.

[0052] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, the oxide source materials comprise any one or more of the following: aluminum oxides, silicon oxides, tantalum oxides, boron oxides, hafnium oxides, zirconium oxides, ytterbium oxides, and yttrium oxides.RTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WO

[0053] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, the oxide phase precursor materials comprise one or more of the following: B2O3-SIO2; AEO-AhOs-SiCh, where AE comprises at least one of Be, Ca, Ba and Sr; REO-AhOa-SiCh, where RE comprises at least one of La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y; and, combinations thereof.

[0054] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, depositing comprises one or more of the following techniques: slurry infiltration and chemical vapor infiltration.

[0055] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, the interface coating or the structural support material or both the interface coating and the structural support material comprises one or more of the following materials: carbides, carbon materials, nitrides, borides, and combinations thereof.

[0056] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, the carbides comprise one or more of the following: silicon carbides, boron carbides, zirconium carbides, hafnium carbides, tantalum carbides, niobium carbides, titanium carbides, molybdenum carbides, tungsten carbides, vanadium carbides, chromium carbides, ytterbium carbides, yttrium carbides, and combinations thereof.

[0057] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, the carbon materials comprise one or more of the following: pyrolytic carbons, graphite and combinations thereof.

[0058] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, the nitrides comprise one or more of the following: silicon nitrides, titanium nitrides, boron nitrides, zirconium nitrides, hafnium nitrides, niobium nitrides, tantalum nitrides, vanadium nitrides, ytterbium nitrides, yttrium nitrides, and combinations thereof.RTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WO

[0059] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, the borides comprise one or more of the following: silicon borides, titanium borides, zirconium borides, hafnium borides, niobium borides, tantalum borides, vanadium borides, ytterbium borides, yttrium borides, and combinations thereof.

[0060] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, the apparatus comprises any one or more of the following: a vacuum chamber, a slurry infiltration chamber, a freeze dryer, and combinations thereof.

[0061] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, the partially densified ceramic matrix composite further comprises densifying the partially densified ceramic matrix composite using any one or more of the following techniques: melt-infiltration, polymer infiltration and pyrolysis, atomic layer deposition, chemical vapor infiltration, physical vapor deposition, chemical vapor deposition, and combinations thereof.

[0062] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, melt-infiltrating further comprises melt-infiltrating one or more of the following molten infiltrants: metals, metalloids, metal alloys, metalloid alloys, glasses, and combinations thereof.

[0063] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, the partially densified ceramic matrix composite further comprises heat treating a densified ceramic matrix composite.

[0064] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, drying further comprises evaporating one or more liquid phases of the slurry composition within the slurry infiltrated partially densified ceramic matrix composite.RTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WO

[0065] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, drying further comprises sublimating one or more liquid phases of the slurry composition within the slurry infiltrated partially densified ceramic matrix composite.

[0066] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, drying further comprises subjecting the solidified partially densified ceramic matrix composite at a temperature of at least room temperature to at least one of the following processes: aging, drying, curing, and combinations thereof.

[0067] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, aging or drying further comprises at least partially evaporating one or more liquid phases of the slurry composition of the solidified partially densified ceramic matrix composite.

[0068] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, the partially densified ceramic matrix composite further comprises curing at least one remaining binder present in the partially densified ceramic matrix composite.

[0069] In further embodiments of the present disclosure, including further embodiments of the above exemplary embodiments, the partially densified ceramic matrix composite further comprises cross-linking at least one remaining binder present in the partially densified ceramic matrix composite.BRIEF DESCRIPTION OF FIGURES

[0070] The features of the disclosure believed to be novel and the elements characteristic of the invention are set forth with particularity in the appended claims. The figures are for illustration purposes only and are not drawn to scale. The disclosure itself, however, both as to organizationRTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WOand method of operation, can best be understood by reference to the description of the preferred embodiment(s) which follows, taken in conjunction with the accompanying drawings in which:

[0071] FIG. 1 illustrates an uneven solid particle distribution that may occur during a standard drying procedure of a partially densified ceramic matrix material.

[0072] FIG. 2 shows an exemplary uniform distribution of solid particles in a partially densified ceramic matrix material during production when rapidly solidifying.

[0073] FIG. 3 is a flowchart illustrating an exemplary method for fabricating a melt-infiltrated ceramic matrix composite via uniformly distributing solid particles within a partially densified ceramic matrix material intermediate product.

[0074] FIG.4 is a flowchart illustrating various exemplary embodiments for rapidly solidifying the liquid phases of a slurry composition within a slurry infiltrated partially densified ceramic matrix composite.DETAILED DESCRIPTION OF THE INVENTION

[0075] The embodiments of the present disclosure can comprise, consist of, and consist essentially of the features and / or steps described herein, as well as any of the additional or optional ingredients, components, steps, or limitations described herein or would otherwise be appreciated by one of skill in the art. It is to be understood that all concentrations disclosed herein are by weight percent (wt. %.) based on a total weight of the composition unless otherwise indicated.

[0076] As used herein, a "coated preform" or "coated substrate" refers to an interface coated ceramic fiber preform or an interface coated ceramic fiber substrate. As also used herein, a "partially densified CMC" or "partially densified ceramic matrix composite" refers to a coated substrate or preform that includes a structural support material layer that facilitates rigidizationRTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WOof the preform to become self-supporting, also known as a rigidized coated substrate or rigidized coated preform. As also used further herein, a "ceramic matrix composite" or "CMC" refers to a matrix infiltrated into the coated substrate or coated preform or alternatively, a matrix infiltrated into the rigidized partially densified CMC.

[0077] The present disclosure introduces an innovative process that replaces conventional freezing techniques with a combination of rapid solidification and drying techniques, such as blast freezing or flash freezing, followed by, e.g., evaporation or sublimation. These combined techniques employ rapid freezing technologies, such as liquid nitrogen or other cryogenic materials in liquid or gas form, rather than standard freeze dryers or freezers whose freezing rates are slower by comparison. The exemplary process disclosed herein may ensure the solvent in the slurry solidifies within a matter of seconds to minutes, effectively prevents various particles in the slurry from settling during rapid solidification, and ensures a more uniform distribution throughout a porous structure of a partially densified ceramic matrix composite.

[0078] By immobilizing the various particles almost instantaneously, the various particles may uniformly distribute throughout the porous structure of the partially densified ceramic matrix composite. Once frozen, the partially densified ceramic matrix composite may undergo a low-temperature, high-vacuum drying process, taking place in either a freeze dryer or a vacuum chamber capable of maintaining the requisite low temperatures. During this stage, the frozen solvent undergoes sublimation, and the vaporized solvent may be evacuated from the structure. Once evacuated, a porous partially densified ceramic matrix composite with uniformly distributed pores, particles, carbon sources, and other constituents may result.

[0079] Referring now to Fig. 1, the potential effect of a standard drying procedure on the distribution of solid particles, e.g., a carbon source, in a CMC is illustrated. The black dots 10 may represent diamond particles. However, any solid particles of any size may be distributed in the partially densified ceramic matrix composite can be represented by the black dots 10, e.g., carbide or metal particles that may be desired to be present in the CMC material. As can be seen,RTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WOthe black dots 10 may designate the solid particles, e.g., carbon source, that may clog up a path between two fibers and / or fiber tows 20, 30 by non-uniformly distributing within the space around and proximate to the fibers and / or fiber tows (see FIG. 1).

[0080] During melt infiltration, solid particles may react with the molten infiltrating material. This reaction may produce volumetric and / or chemistry changes in both the molten infiltrating material and solid particles. For example, once melt infiltrated, solid particles, such as a diamond particle, may react with the molten infiltrating silicon alloy to form silicon carbide. The resulting reaction formed silicon carbide with a volume approximately 3.6 times the volume of the original diamond particles may result in the "choke off" of infiltration paths if the carbon source is not distributed uniformly or is packed too tightly at certain locations within the partially densified ceramic matrix material. Additionally, the diamond-to-silicon carbide reaction removes silicon from the melt infiltrating silicon alloy, which alters the final chemistry of the resultant silicide phase(s) when the silicon alloy solidifies. In such an embodiment, a non-uniform distribution of diamond particles will result in a non-uniform distribution of the resultant silicon carbide, diamond and silicide phases. The resulting ceramic matrix composite will exhibit and possess high internal stresses due to a coefficient of thermal expansion (CTE) mismatch between the aforementioned materials. The non-uniformly distributed materials may also lead to other properties, e.g., thermal conductivity, that then also become non-uniform throughout the resultant CMC material. These additional non-uniform properties of the resultant CMC material again may lead to an inferior or defective resultant CMC material.

[0081] Referring now to FIG. 2, the solid particles, e.g., diamond particles, in the partially densified ceramic matrix composite may be even more uniformly distributed when rapidly solidifying and either a solvent containing a gelling agent or a solvent containing a binder and aforementioned slurry additives are used. In either exemplary embodiment, each exemplary slurry may lead to a more evenly distributed solid particles within the infiltrated partially densified ceramic matrix composite. Rapidly solidifying utilizing either slurry additives or gelling agents may produce uniformly distributed particles that avoid such future "choking off"RTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WOoccurrences. For example, once infiltrated and frozen, the solid particles represented by black dots 10 may be uniformly distributed in the space(s) between two fibers and / or fiber tows 20, 30 of the partially densified ceramic matrix composite where the open space between the solid particles may later be filled with silicide.

[0082] A further way to achieve more uniform solid particle distribution may be made by minimizing ice crystal size to the extent the resultant ice crystals may be smaller than the size of the solid particles within the partially densified ceramic matrix composite. During solidification, large ice crystals may move particles to ice crystal grain boundaries. Such particle movement may cause unwanted particle packing, i.e., non-uniform solid particle distribution, at such grain boundaries, and may achieve lower particle concentration at areas from where particles may have been moved by the large ice crystals. However, ice crystal size may be suppressed when either gelling the slurry prior to solidifying or utilizing a solvent containing a binder and slurry additives including, but not limited to, ice nucleators, recrystallization inhibitors, combinations thereof, and the like. In either embodiment, if either the gel achieves sufficient strength or the ice crystal size is suppressed, ice crystals may form significantly smaller than the size of the solid particle(s). As a result, the solid particle(s) may exhibit and possess uniform distribution.

[0083] Referring now to FIG. 3, an exemplary process 100 for fabricating a melt-infiltrated ceramic matrix composite via uniformly distributing solid particles within a partially densified ceramic matrix composite intermediate product is shown. At an exemplary step 200 of FIG. 3, a ceramic fiber preform containing fibers and / or fiber tows may be fabricated. The ceramic fiber preform may be fabricated using any suitable technique known. Suitable fibers for use as the fibers and / or fiber tows may include, but are not limited to, silicon carbide, carbon, aluminum oxide, silicon nitride, combinations thereof, and the like.

[0084] Next, at an optional exemplary step 300 of FIG. 3, the fibers and / or fiber tows of the ceramic fiber preform may be coated with an interface coating to form a coated preform. Suitable interface coating materials may include, but are not limited to, carbides such as siliconRTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WOcarbides, boron carbides, zirconium carbides, hafnium carbides, tantalum carbides, niobium carbides, titanium carbides, molybdenum carbides, tungsten carbides, vanadium carbides, chromium carbides, ytterbium carbides, yttrium carbides, combinations thereof, and the like; carbon materials such as pyrolytic carbons, graphite in one or more of flake, particle or fiber form; carbon nanotubes, carbon nanofibers, diamonds, combinations thereof, and the like; nitrides such as silicon nitrides, titanium nitrides, boron nitrides, zirconium nitrides, hafnium nitrides, niobium nitrides, tantalum nitrides, vanadium nitrides, ytterbium nitrides, yttrium nitrides, combinations thereof, and the like; borides such as silicon borides, titanium borides, zirconium borides, hafnium borides, niobium borides, tantalum borides, vanadium borides, ytterbium borides, yttrium borides, combinations thereof, and the like; combinations thereof, and the like. The interface coating materials may be deposited using any suitable deposition technique. Suitable deposition techniques may include, but are not limited to, chemical vapor infiltration, slurry infiltration, combinations thereof, and the like.

[0085] Next, at an exemplary step 400 of FIG. 3, IFC coated fibers and / or fiber tows of the coated preform may be coated further with a structural support material to form a partially densified ceramic matrix composite. Suitable structural support materials may include, but are not limited to, carbides such as silicon carbide, boron carbide, combinations thereof, and the like; carbon materials such as pyrolytic carbon, combinations thereof, and the like; nitrides such as silicon nitride, combinations thereof, and the like; combinations thereof, and the like. The structural support materials may be deposited using any suitable deposition technique. Suitable deposition techniques may include, but are not limited to, chemical vapor infiltration, slurry infiltration, combinations thereof, and the like.

[0086] Next, at an exemplary step 500 of FIG. 3, an exemplary slurry containing various additives suitable for infiltration into the partially densified ceramic matrix composite may be prepared. Slurry additives, e.g., solid particles, binders, gelling agents, dispersants, wetting agents, pH adjustors, ice nucleators, recrystallization inhibitors, combinations thereof, and the like, may be used to enhance the properties of the slurry. More particular, a combination of solid particles;RTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WOsolvent; binder and / or gelling agent; dispersant and / or wetting agent; pH adjustor; ice nucleator; ice crystal modifiers; and, recrystallization inhibitor may improve the exemplary combined rapid solidification and drying technique disclosed herein and achieve the desired uniform particle distribution within the partially densified ceramic matrix composite. Additives of any shape, e.g., particulate, flake or fiber; or size, e.g., nanometer, sub-micron, micron, combinations comprising any one of the foregoing, and the like; may be added to a slurry prior to slurry infiltration taking place.

[0087] The solid particles may include, but are not limited to, carbon-based materials; various carbides, including but not limited to, boron carbides, zirconium carbides, hafnium carbides, tantalum carbides, niobium carbides, titanium carbides, molybdenum carbides, tungsten carbides, vanadium carbides, chromium carbides, ytterbium carbides, yttrium carbides, combinations thereof, and the like; graphite, e.g., flake, particle or fiber forms; carbon nanotubes, carbon nanofibers, diamond particles, combinations thereof, and the like; nitrides, including but not limited to, silicon nitrides, titanium nitrides, boron nitrides, zirconium nitrides, hafnium nitrides, niobium nitrides, tantalum nitrides, vanadium nitrides, ytterbium nitrides, yttrium nitrides, combinations thereof, and the like; borides, including but not limited to, silicon borides, titanium borides, zirconium borides, hafnium borides, niobium borides, tantalum borides, vanadium borides, ytterbium borides, yttrium borides, combinations thereof, and the like; silicides including, but not limited to, hafnium silicide, zirconium silicide, titanium silicide, tantalum silicide, iridium silicide, molybdenum silicide, tungsten silicide, boron silicide, niobium silicide, ytterbium silicide, vanadium silicide, scandium silicide, yttrium silicide, combinations thereof, and the like; oxides, including but not limited to, aluminum oxides, silicon oxides, tantalum oxides, boron oxides, hafnium oxides, zirconium oxides, ytterbium oxides, yttrium oxides, combinations thereof, and the like; oxide phase precursors including, but not limited to, alkaline earth metal alumino silicates, boro-silicates (BzOs-SiOz), alkaline earth metal alumino silicates, such as AEO-AhOs-SiO?, where AE = Be, Ca, Ba and Sr; rare earth alumino silicates, such as REO-AhOs-SiCh, where RE = La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y;RTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WOcombinations thereof, and the like; metals including, but not limited to, zirconium, hafnium, tantalum, niobium, titanium, molybdenum, tungsten, vanadium, chromium, ytterbium, yttrium, combinations thereof, and the like; metalloids including, but not limited to, silicon, boron, combinations thereof, and the like; alloys comprising any one or more of the aforementioned metal(s) and / or metalloid(s); as well as combinations thereof, and the like.

[0088] The binders and gelling agents may bind particles together in the resultant matrix and also may prevent the slurry from leaking out of the preform post infiltration. Suitable binders may include, but are not limited to, polyvinyl alcohol (PVA), polyvinyl butyral (PVB), lignosulfonates, acrylic co-polymers, combinations thereof, and the like. Suitable gelling agents may include, but are not limited to, aluminosilicate, carboxymethylcellulose, starches, methyl cellulose, carbo-ethyl cellulose, hydroxypropyl methyl cellulose, gellan gum, gelatins, pectin, aragose gum, curdlan gum, xanthium gum, konjac gum, carrageenan gum, alginates, sodium alginate, agar gum, non-ionic copolymer surfactants; combinations thereof, and the like.

[0089] The dispersants and wetting agents may reduce air bubbles, improve slurry penetration within the preform, prevent particle clustering, increase particle loading, and reduce slurry viscosity. Suitable dispersant and wetting agents may include, but are not limited to, Triton X-100, Dysperbyk BYK156, combinations thereof, and the like. The pH adjustors may increase particle dispersion within the slurry that may improve slurry penetration within the preform, prevent particle clustering, increase particle loading, and reduce slurry viscosity. For example, when seeking to increase the pH, ammonia may be added to the slurry. In another example, when seeking to decrease the pH, hydrochloric acid may be added to the slurry.

[0090] The ice nucleators may increase ice nucleation sites that lead to forming smaller, more dispersant sized ice crystals resulting in more uniform particle distribution. The recrystallization inhibitors may prevent ice crystal growth during frozen storage, create melting point hysteresis and promote super cooling. As a result, ice crystal size may be reduced and improved particle distribution may be achieved.RTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WO

[0091] When preparing the slurry at exemplary step 500, slurry constituents such as the solvent, binders, gelling agents, dispersants, wetting agents, ice nucleators, recrystallization inhibitors, may be mixed using a suitable mixing technique. Suitable mixing techniques may include, but are not limited to, high shear mixing, combinations thereof, and the like. Next, one or more aforementioned solid particles may be added to the mixture and the resultant mixture may be mixed further using the suitable mixing techniques. Next, one or more aforementioned pH adjustor(s) may be added to the mixture and the resultant mixture may be mixed further using the suitable mixing techniques. Next, the resultant slurry may be degassed under a vacuum.

[0092] Next, once degassed, at an exemplary step 600 of FIG. 3, the slurry may be infiltrated into the partially densified ceramic matrix composite. In preparation, the partially densified ceramic matrix composite first may be placed in a vacuum chamber. Once the vacuum is applied, the partially densified ceramic matrix composite may be submerged entirely within the exemplary slurry. Once submerged entirely, the vacuum applied may be released. If the exemplary slurry contained a gelation agent, the gelling process of the slurry within the partially densified ceramic matrix composite may begin occurring. The gelling process may be modulated by altering the temperature and / oradjusting the pH. Once gelation is completed, the partially densified ceramic matrix composite may be extracted from the gel and removed from vacuum chamber or pressure vessel. Any excess gel present may be removed from the exterior of the partially densified ceramic matrix composite.

[0093] Next, at an exemplary step 700 of FIG. 3, the slurry infiltrated partially densified ceramic matrix composite may be frozen. In at least one embodiment, frozen may mean rapid freezing such as flash freezing or blast freezing. In at least one additional embodiment, frozen may also mean rapid solidification of one or more liquid phases. To achieve the desired extent of freezing, freezing parameters may be monitored and modified as necessary. In at least one embodiment, the freezing parameters may include, but are not limited to, a temperature range of approximately -10°C to approximately -70°C; a pressure range of approximately 0.001 Torr to approximately 7,600 Torr; a freezing rate of approximately 200°C / sec to approximatelyRTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WO0.1°C / sec; solidification direction, combinations thereof, and the like, to achieve the desired size of the ice crystals within the slurry infiltrated partially densified ceramic matrix composite. Once frozen, in at least one embodiment, the frozen partially densified ceramic matrix composite may be dried using any one or more techniques. Suitable drying techniques may include any technique capable of, in at least one exemplary embodiment, evaporating one or more solidified liquid phases and leaving behind a solid structure within the partially densified ceramic matrix composite or, in at least one other embodiment, sublimating one or more solidified liquid phases and again leaving behind the aforementioned solid structures. In at least one other embodiment, the slurry-infiltrated, partially densified ceramic matrix composite may undergo an aging, drying, and / or curing process at room temperature and / or elevated temperatures. During this process, one or more liquid phases of the slurry composition initially may be partially or fully evaporated. Subsequently, the remaining binder or binders present may undergo a curing technique and / or a crosslinking process to achieve the desired properties suitable for a future densification step.

[0094] Referring specifically now to FIG. 4, one or more techniques to rapidly solidify the one or more liquid phases of the slurry infiltrated partially densified ceramic matrix composite may be utilized as illustrated. For example, in at least one embodiment, an apparatus may be provided at an exemplary step 705. The apparatus may accommodate the slurry infiltrated partially densified ceramic matrix composite and the rapid solidification process disclosed herein. A suitable apparatus may include, but is not limited to, a freeze dryer, a vacuum chamber, a slurry infiltration chamber; individually, and combinations thereof, and the like. The apparatus may include a vessel or other receptacle for receiving the slurry infiltrated partially densified ceramic matrix composite. At an exemplary step 710 of FIG. 4, the slurry infiltrated partially densified ceramic matrix composite may be loaded into the vessel or other receptacle within the apparatus. In at least one embodiment, when a slurry infiltration chamber is utilized, a partially densified ceramic matrix composite has already been loaded into the vessel or receptacle prior to undergoing slurry infiltration and, once slurry infiltrated, is now prepared to solidify one or more liquid phases of the slurry composition within the partially densified ceramic matrixRTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WOcomposite. Once loaded, the slurry infiltrated partially densified ceramic matrix composite may be frozen using any one of a number of techniques as will be described next.

[0095] In at least one exemplary embodiment, at an exemplary step 715 of FIG. 4, a cryogenic material, e.g., any one or more phases of nitrogen (N2), oxygen (O2), helium (He), and any other materials capable of achieving a supercooled temperature, e.g., a liquid or gas in supercooled form, may be charged into the vessel or receptacle containing the slurry infiltrated partially densified ceramic matrix composite. Next, at an exemplary step 720 of FIG. 4, the cryogenic material, e.g., liquid N2, may be charged until the slurry infiltrated partially densified ceramic matrix composite is substantially or entirely submerged. A vacuum may be applied to accelerate rapid solidification by drawing the liquid N2into the partially densified ceramic matrix composite for a time period of approximately 1 second to approximately 1 hour, and solidifying the slurry contained therein. In the alternative, the liquid N2 may be charged at a positive pressure, higher than the internal pressure of the vessel or receptacle, to force the liquid N2 into the partially densified ceramic matrix composite for a time period of approximately 1 second to approximately 1 hour, and solidifying the slurry contained therein. In at least one embodiment, at an optional exemplary step 725 of FIG. 4, ultrasound also may be applied as the slurry infiltrated partially densified ceramic matrix composite is being submerged. Applying ultrasound may reduce temperature gradient(s) during rapid solidification of the slurry. In turn, reducing temperature gradient(s) may enhance the uniformity and speed of slurry solidification. Once the slurry infiltrated partially densified ceramic matrix composite is frozen, the process may proceed to the next exemplary step 800 of FIG. 3 discussed further below.

[0096] In at least one other exemplary embodiment, at an exemplary step 730 of FIG. 4, a cryogenic material, e.g., any one or more phases of nitrogen (N2), may be charged into the vessel or receptacle containing the slurry infiltrated partially densified ceramic matrix composite. The cryogenic material, e.g., liquid N2, may be charged until the slurry infiltrated partially densified ceramic matrix composite is substantially or entirely submerged. Next, at an exemplary step 735 of FIG. 4, a vacuum may be applied to accelerate rapid solidification by drawing, e.g., the liquidRTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WON2 into the partially densified ceramic matrix composite for a time period of approximately 1 second to approximately 1 hour, and solidifying the slurry contained therein. In at least one embodiment, at an optional exemplary step 740 of FIG. 4, ultrasound also may be applied as the slurry infiltrated partially densified ceramic matrix composite is frozen. Applying ultrasound may reduce temperature gradient(s) during rapid solidification of the slurry. In turn, reducing temperature gradient(s) may enhance the uniformity and speed of slurry solidification. Once the slurry infiltrated partially densified ceramic matrix composite is frozen, the process may proceed to the next exemplary step 800 of FIG. 3 discussed further below.

[0097] In at least yet one other exemplary embodiment, at an exemplary step 745 of FIG. 4, a cryogenic material, e.g., any one or more phases of N2, may be charged into the vessel or receptacle containing the slurry infiltrated partially densified ceramic matrix composite. Next, at an exemplary step 750 of FIG. 4, the cryogenic material, e.g., gaseous N2, may be charged until the slurry infiltrated within the partially densified ceramic matrix composite is frozen. A vacuum may be applied to accelerate rapid solidification by drawing the gaseous N2 into the partially densified ceramic matrix composite for a time period of approximately 1 second to approximately 1 hour, and solidifying the slurry contained therein. In the alternative, the gaseous N2 may be charged at a positive pressure, higher than the internal pressure of the vessel or receptacle, to force the gaseous N2 into the partially densified ceramic matrix composite for a time period of approximately 1 second to approximately 1 hour, and solidifying the slurry contained therein. In at least one embodiment, at an optional exemplary step 755 of FIG. 4, ultrasound also may be applied as the slurry infiltrated partially densified ceramic matrix composite is frozen. Applying ultrasound may reduce temperature gradient(s) during rapid solidification of the slurry. In turn, reducing temperature gradient(s) may enhance the uniformity and speed of slurry solidification. Once the slurry infiltrated partially densified ceramic matrix composite is frozen, the process may proceed to the next exemplary step 800 of FIG. 3 discussed further below.

[0098] In at least yet one other exemplary embodiment, at an exemplary step 760 of FIG. 4, a cryogenic material, e.g., any one or more phases of N2, may be sprayed onto the slurry infiltratedRTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WOpartially densified ceramic matrix composite contained within the vessel or receptacle. Next, at an exemplary step 765 of FIG. 4, the cryogenic material, e.g., liquid N2, may be sprayed until the slurry infiltrated within the partially densified ceramic matrix composite is frozen. A vacuum may be applied to accelerate rapid solidification by drawing the liquid N2 into the partially densified ceramic matrix composite for a time period of approximately 1 second to approximately 1 hour, and solidifying the slurry contained therein. In the alternative, the liquid N2 may be charged at a positive pressure, higher than the internal pressure of the vessel or receptacle, to force the liquid N2 into the partially densified ceramic matrix composite for a time period of approximately 1 second to approximately 1 hour, and solidifying the slurry contained therein. In at least one embodiment, at an exemplary step 770 of FIG. 4, ultrasound also may be applied as the slurry infiltrated partially densified ceramic matrix composite is frozen. Applying ultrasound may reduce temperature gradient(s) during rapid solidification of the slurry. In turn, reducing temperature gradient(s) may enhance the uniformity and speed of slurry solidification. Once the slurry infiltrated partially densified ceramic matrix composite is frozen, the process may proceed to the next exemplary step 800 of FIG. 3 discussed further below.

[0099] In at least yet one other exemplary embodiment, at an exemplary step 775 of FIG. 4, a slush containing a mixture of phases of a cryogenic material, e.g., solid N2, liquid N2 and / or gaseous N2, may be charged within the vessel or receptacle containing the slurry infiltrated partially densified ceramic matrix composite. Next, at an exemplary step 780, the slurry infiltrated partially densified ceramic matrix composite may be substantially or entirely submerged or exposed to the slush of cryogenic material, e.g., a N2 slush, until frozen. A vacuum may be applied to accelerate rapid solidification by drawing the N2 slush into the partially densified ceramic matrix composite for a time period of approximately 1 second to approximately 1 hour, and solidifying the slurry contained therein. In the alternative, the N2 slush at a positive pressure, higher than the internal pressure of the vessel or receptacle, to force the N2 slush into the partially densified ceramic matrix composite for a time period of approximately 1 second to approximately 1 hour, and solidifying the slurry contained therein. In at least one embodiment,RTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WOat exemplary step 770, ultrasound also may be applied as the slurry infiltrated partially densified ceramic matrix composite is frozen. Applying ultrasound may reduce temperature gradient(s) during rapid solidification of the slurry. In turn, reducing temperature gradient(s) may enhance the uniformity and speed of slurry solidification. Once the slurry infiltrated partially densified ceramic matrix composite is frozen, the process may proceed to the next exemplary step 800 of FIG. 3 discussed further below.

[0100] Next, at exemplary step 800 of FIG. 3, once achieving the desired size of the ice crystals, the partially densified ceramic matrix composite containing the solidified liquid phases of the slurry composition may be dried. In at least one embodiment, a vacuum may be applied to begin sublimating the solidified liquid phases of the slurry composition within the partially densified ceramic matrix composite. The solidified liquid phases undergo sublimation and may transition directly from a solid phase to a vapor phase without passing through a liquid phase. Sublimation may leave the remaining solid particles uniformly spaced, as the absence of liquid solvent may eliminate surface tension, which may otherwise cause particle agglomeration. Consequently, sublimation, rather than melting, must be achieved to prevent clustering and porosity within the partially densified ceramic matrix composite. In at least one other embodiment, the partially densified ceramic matrix composite containing the solidified liquid phases of the slurry composition may be loaded into a drying apparatus. Suitable drying apparatus for use herein may achieve and maintain a temperature capable of melting and evaporating the solidified liquid phases of the slurry composition, yet leave the uniformly distributed particles and / or solid structures in place within the pores, porous network, or both of the partially densified ceramic matrix composite.

[0101] After sublimation occurs, the partially densified ceramic matrix composite may be placed in a drying oven. Any drying oven equipped with a moisture free container for holding the sublimated frozen partially densified ceramic matrix composite may be considered suitable for use herein. The drying oven may be operated at a temperature sufficient to drive off any residual moisture within the partially densified ceramic matrix composite. In at least oneRTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WOembodiment, a sufficient temperature range may be approximately 70°Cto approximately 500°C and, more particularly, approximately 100°Cto approximately 300°C.

[0102] Next, at an exemplary step 900 of FIG. 3, the dried partially densified ceramic matrix composite may be densified to form a fully densified ceramic matrix composite. Suitable densification techniques may include, but are not limited to, melt-infiltration, polymer infiltration and pyrolysis, deposition techniques, such as, but not limited to, atomic layer deposition, chemical vapor infiltration, physical vapor deposition, chemical vapor deposition; individually, and combinations thereof, and the like.

[0103] In at least one embodiment, when densifying via melt-infiltration, a liquid metalloid, metalloid alloy or oxide, for example, silicon, silicon alloy, or alumino-silicate glass, may be infiltrated into the sublimated partially densified ceramic matrix composite containing the solid particles suspended and uniformly distributed therein. The open spaces between the fibers and / or fiber tows should contain uniformly distributed solid particles, which are not clumped together, and thereby allowing the pores and / or porous network to be adequately open for the infiltrant, e.g., liquid metal, liquid metalloid, metal alloy, metalloid alloy or glass, to infiltrate uniformly between the fibers and / or fiber tows of the sublimated partially densified ceramic matrix composite and around the solid particles. Moreover, open spaces that do not contain solid particles also may be minimized by the uniform distribution of solid particles to avoid open porosity within the final CMC. The reaction of the solid particles, e.g., diamond particles, with the melt-infiltrant, e.g., the liquid metalloid, e.g., a silicon; metalloid alloy, e.g., a silicon alloy; or glass, e.g., an alumino-silicate glass, may lead to the formation of silicon carbide.

[0104] When the solid particles include an oxide phase precursor material and the molten infiltrant is an oxide, the aforementioned reaction may lead to forming an oxide phase. In at least one embodiment, the resultant oxide phase may include, but is not limited to, an oxide crystalline structure comprising at least two of the following oxides, alumino silicates or both oxides and alumino silicates: BzOa-SiOz; alumino silicates of oxides of one or more of: Be, Ca, Ba,RTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WOSr, and combinations thereof; alumino silicates of oxides of one or more of: La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Y, and combinations thereof; and, combinations thereof. In at least one other embodiment, the resultant oxide phase may include, but is not limited to, cordierite, mullite, sapphirine, combinations thereof, and the like. In at least yet one other embodiment, the resultant oxide phase may include, but is not limited to, a series of molten glasses each comprising MgO, AIO1.5, and SiOz but each having a different eutectic point, that may represent a mixture of at least two of the following glasses: cordierite, mullite, sapphirine, spinel, alumina, periclase, and forsterite.

[0105] Next, at an exemplary optional step 1000 of FIG. 3, the resultant melt-infiltrated CMC may be heat-treated to react the solid particles with the melt infiltrant as well as at least one or more metals, metal alloys, metalloids, metalloid alloys, oxides aforementioned various particles, fiber protection coatings, combinations thereof, and the like, therein. Melt infiltration may be carried out at low temperatures and dwell times relative to heat treatment temperatures and dwell times in order to minimize reaction of molten materials and solid particles during the melt infiltration step. If the aforementioned reaction is not minimized, unwanted material segregation or infiltration "choking off" may result. Suitable melt infiltration temperature range may be approximately 1100°C to approximately l,650°C and, more particularly, approximately l,290°C to approximately l,600°C. In correlation with the melt infiltration temperature range, suitable dwell time range may be approximately 1 minute to approximately 10 hours. Suitable heat treatment temperature range may be approximately l,300°C to approximately 2,000°C. In correlation with the heat treatment temperature range, suitable dwell times may be approximately 10 minutes to approximately 48 hours. Heat treatment temperatures and hold times may be designed to achieve the desired amount of reaction between the molten materials and the solid particles. In most circumstances, the desired amount of reaction may be greater than approximately 95% of the total amount of solid particles.

[0106] As discussed herein, combining rapid solidification and drying techniques may improve both the efficiency and quality of the slurry infiltration technique. The aforementionedRTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WOcombination may promote a highly uniform distribution of particles and pore structure. A more uniform distribution of particles within the part may lead to a more effective reaction between the molten materials and the carbon source. In additional, a more uniform distribution may also ensure consistent dispersion of solid filler particles throughout the partially densified ceramic matrix composite. In turn, the performance and consistency of subsequent densification processes performed also may be enhanced. Such uniformity may promote an even distribution of high-temperature capable phases within the matrix of the resultant composite, minimizing localized GTE mismatches and thereby reducing the likelihood of cracking. Furthermore, the exemplary process may not only improve the thermal conductivity of the resultant CMC components but may also enhance their mechanical properties. As a consequence, the resultant CMC components may exhibit improved overall performance and reliability when produced through the exemplary process disclosed herein.

[0107] While the present disclosure has been particularly described, in conjunction with specific preferred embodiments, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. It is therefore contemplated that the appended claims will embrace any such alternatives, modifications and variations as falling within the true scope and spirit of the present disclosure.

Claims

RTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WOCLAIMSWhat is claimed is:

1. A process for fabricating a partially densified ceramic matrix composite, comprising the steps of:fabricating a ceramic fiber preform comprising at least one fiber, at least one fiber tow, or at least one fiber and fiber tow;optionally depositing an interface coating on the at least one fiber, the at least one fiber tow, or the at least one fiber and fiber tow;depositing a structural support material on the at least one fiber, the at least one fiber tow, or the at least one fiber and fiber tow to form a partially densified ceramic matrix composite comprising at least one pore, at least one porous network or at least one pore and porous network;preparing at least one slurry composition comprising at least one solid particle; infiltrating the slurry composition into the partially densified ceramic matrix composite and depositing the at least one solid particle into the at least one pore, the at least one porous network or the at least one pore and porous network;rapidly solidifying one or more liquid phases of the slurry composition within a slurry infiltrated partially densified ceramic matrix composite; anddrying a solidified slurry infiltrated partially densified ceramic matrix composite.

2. The process of claim 1, wherein rapidly solidifying comprises the following steps:loading the slurry infiltrated partially densified ceramic matrix composite into an apparatus;charging a liquid cryogenic material into the apparatus;rapidly solidifying the one or more liquid phases of the slurry composition within the slurry infiltrated partially densified ceramic matrix composite; andoptionally, applying ultrasound during rapid solidification.RTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WO3. The process of claim 1, wherein rapidly solidifying comprises the following steps:loading the slurry infiltrated partially densified ceramic matrix composite into an apparatus;charging a liquid cryogenic material into the apparatus;applying a vacuum within the apparatus;rapidly solidifying the one or more liquid phases of the slurry composition within the slurry infiltrated partially densified ceramic matrix composite; andoptionally, applying ultrasound during rapid solidification.

4. The process of claim 1, wherein rapidly solidifying comprises the following steps:loading the slurry infiltrated partially densified ceramic matrix composite into an apparatus;applying a vacuum within the apparatus;charging a liquid cryogenic material into the apparatus;rapidly solidifying the one or more liquid phases of the slurry composition within the slurry infiltrated partially densified ceramic matrix composite; andoptionally, applying ultrasound during rapid solidification.

5. The process of claim 1, wherein rapidly solidifying comprises the following steps:loading the slurry infiltrated partially densified ceramic matrix composite into an apparatus;charging a gaseous cryogenic material into the apparatus;rapidly solidifying the one or more liquid phases of the slurry composition within the slurry infiltrated partially densified ceramic matrix composite; andoptionally, applying ultrasound during rapid solidification.

6. The process of claim 1, wherein rapidly solidifying comprises the following steps:RTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WOloading the slurry infiltrated partially densified ceramic matrix composite into an apparatus;spraying a liquid cryogenic material onto the slurry infiltrated partially densified ceramic matrix composite;rapidly solidifying the slurry composition disposed within the slurry infiltrated partially densified ceramic matrix composite; andoptionally, applying ultrasound during rapid solidification.

7. The process of claim 1, wherein rapidly solidifying comprises the following steps:loading the slurry infiltrated partially densified ceramic matrix composite into an apparatus;charging a slush comprising at least one phase of cryogenic materials into the apparatus; rapidly solidifying one or more liquid phases of the slurry composition within the slurry infiltrated partially densified ceramic matrix composite; andoptionally, applying ultrasound during rapid solidification.

8. The process according to claim 1, wherein the at least one slurry further comprises one or more of the following: a solvent, a binder, a gelling agent, a dispersant, a wetting agent, a pH adjustor, an ice nucleator, a recrystallization inhibitor, and combinations thereof.

9. The process of claim 8, wherein the gelling agent, the binders or both the gelling agent and the binders comprise any one or more of the following: polyvinyl alcohol (PVA), polyvinyl butyral (PVB), lignosulfonates, starches aluminosilicate, carboxymethylcellulose, methyl cellulose, carbo-ethyl cellulose, hydroxypropyl methyl cellulose, gellan gum, gelatins, pectin, aragose gum, curdlan gum, xanthium gum, konjac gum, carrageenan gum, alginates, sodium alginate, agar gum, non-ionic copolymer surfactants, and combinations thereof.RTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WO10. The process of claim 1, wherein the at least one solid particle comprises any one or more of the following materials: carbon source materials, nitride source materials, boride source materials, oxide source materials, oxide phase precursor materials, metal source materials and metalloid source materials.

11. The process of claim 10, wherein the carbon source materials comprise any one or more of the following: carbon-based materials, carbide materials, graphite, carbon nanotube, carbon nanofiber, and diamond.

12. The process of claim 11, wherein the carbide materials comprise any one or more of the following: boron carbides, zirconium carbides, hafnium carbides, tantalum carbides, niobium carbides, titanium carbides, molybdenum carbides, tungsten carbides, vanadium carbides, chromium carbides, ytterbium carbides, and yttrium carbides.

13. The process of claim 10, wherein the nitride source materials comprise any one or more of the following: silicon nitrides, titanium nitrides, boron nitrides, zirconium nitrides, hafnium nitrides, niobium nitrides, tantalum nitrides, vanadium nitrides, ytterbium nitrides, and yttrium nitrides.

14. The process of claim 10, wherein the boride source materials comprise any one or more of the following: silicon borides, titanium borides, zirconium borides, hafnium borides, niobium borides, tantalum borides, vanadium borides, molybdenum borides, ytterbium borides, and yttrium borides.

15. The process of claim 10, wherein the oxide source materials comprise any one or more of the following: aluminum oxides, silicon oxides, tantalum oxides, boron oxides, hafnium oxides, zirconium oxides, ytterbium oxides, and yttrium oxides.RTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WO16. The process of claim 10, wherein the oxide phase precursor materials comprise one or more of the following: B2O3-SiC>2; AEO-ALOs-SiCh, where AE comprises at least one of Be, Ca, Ba and Sr; REO-ALOa-SiCh, where RE comprises at least one of La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y; and, combinations thereof.

17. The process of claim 1, wherein depositing comprises one or more of the following techniques: slurry infiltration and chemical vapor infiltration.

18. The process of claim 1, wherein the interface coating or the structural support material or both the interface coating and the structural support material comprises one or more of the following materials: carbides, carbon materials, nitrides, borides, and combinations thereof.

19. The process of claim 18, wherein the carbides comprise one or more of the following: silicon carbides, boron carbides, zirconium carbides, hafnium carbides, tantalum carbides, niobium carbides, titanium carbides, molybdenum carbides, tungsten carbides, vanadium carbides, chromium carbides, ytterbium carbides, yttrium carbides, and combinations thereof.

20. The process of claim 18, wherein the carbon materials comprise one or more of the following: pyrolytic carbons, graphite and combinations thereof.

21. The process of claim 18, wherein the nitrides comprise one or more of the following: silicon nitrides, titanium nitrides, boron nitrides, zirconium nitrides, hafnium nitrides, niobium nitrides, tantalum nitrides, vanadium nitrides, ytterbium nitrides, yttrium nitrides, and combinations thereof.

22. The process of claim 18, wherein the borides comprise one or more of the following: silicon borides, titanium borides, zirconium borides, hafnium borides, niobium borides, tantalum borides, vanadium borides, ytterbium borides, yttrium borides, and combinations thereof.RTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WO23. The process of claim 1, wherein the apparatus comprises any one or more of the following: a vacuum chamber, a slurry infiltration chamber, a freeze dryer, and combinations thereof.

24. The process of claim 1, further comprising densifying the partially densified ceramic matrix composite using any one or more of the following techniques: melt-infiltration, polymer infiltration and pyrolysis, atomic layer deposition, chemical vapor infiltration, physical vapor deposition, chemical vapor deposition, and combinations thereof.

25. The process of claim 24, wherein melt-infiltrating further comprises melt-infiltrating one or more of the following molten infiltrants: metals, metalloids, metal alloys, metalloid alloys, glasses, and combinations thereof.

26. The process of claim 24, further comprising heat treating a densified ceramic matrix composite.

27. The process of claim 1, wherein drying further comprises evaporating one or more liquid phases of the slurry composition within the slurry infiltrated partially densified ceramic matrix composite.

28. The process of claim 1, wherein drying further comprises sublimating one or more liquid phases of the slurry composition within the slurry infiltrated partially densified ceramic matrix composite.RTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WO29. The process of claim 1, wherein drying further comprises subjecting the solidified partially densified ceramic matrix composite at a temperature of at least room temperature to at least one of the following processes: aging, drying, curing, and combinations thereof.

30. The process of claim 29, wherein aging or drying further comprises at least partially evaporating one or more liquid phases of the slurry composition of the solidified partially densified ceramic matrix composite.

31. The process of claim 30, further comprising curing at least one remaining binder present in the partially densified ceramic matrix composite.

32. The process of claim 30, further comprising cross-linking at least one remaining binder present in the partially densified ceramic matrix composite.

33. A partially densified ceramic matrix composite fabricated by a process comprising the steps of:fabricating a ceramic fiber preform comprising at least one fiber, at least one fiber tow, or at least one fiber and fiber tow;optionally depositing an interface coating on the at least one fiber, the at least one fiber tow, or the at least one fiber and fiber tow;depositing a structural support material on the at least one fiber, the at least one fiber tow, or the at least one fiber and fiber tow to form a partially densified ceramic matrix composite comprising at least one pore, at least one porous network or at least one pore and porous network;preparing at least one slurry composition comprising at least one solid particle;RTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WOinfiltrating the slurry composition into the partially densified ceramic matrix composite and depositing the at least one solid particle into the at least one pore, the at least one porous network or the at least one pore and porous network;rapidly solidifying a slurry infiltrated partially densified ceramic matrix composite; and drying a solidified slurry infiltrated partially densified ceramic matrix composite.

34. The partially densified ceramic matrix composite of claim 33, wherein rapidly solidifying comprises the following steps:loading the slurry infiltrated partially densified ceramic matrix composite into an apparatus;charging a liquid cryogenic material into the apparatus;rapidly solidifying the one or more liquid phases of the slurry composition within the slurry infiltrated partially densified ceramic matrix composite; andoptionally, applying ultrasound during rapid solidification.

35. The partially densified ceramic matrix composite of claim 33, wherein rapidly solidifying comprises the following steps:loading the slurry infiltrated partially densified ceramic matrix composite into an apparatus;charging a liquid cryogenic material into the apparatus;applying a vacuum within the apparatus;rapidly solidifying the one or more liquid phases of the slurry composition within the slurry infiltrated partially densified ceramic matrix composite; andoptionally, applying ultrasound during rapid solidification.

36. The partially densified ceramic matrix composite of claim 33, wherein rapidly solidifying comprises the following steps:RTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WOloading the slurry infiltrated partially densified ceramic matrix composite into an apparatus;applying a vacuum within the apparatus;charging a liquid cryogenic material into the apparatus;rapidly solidifying the one or more liquid phases of the slurry composition within the slurry infiltrated partially densified ceramic matrix composite; andoptionally, applying ultrasound during rapid solidification.

37. The partially densified ceramic matrix composite of claim 33, wherein rapidly solidifying comprises the following steps:loading the slurry infiltrated partially densified ceramic matrix composite into an apparatus;charging a gaseous cryogenic material into the apparatus;rapidly solidifying the one or more liquid phases of the slurry composition within the slurry infiltrated partially densified ceramic matrix composite; andoptionally, applying ultrasound during rapid solidification.

38. The partially densified ceramic matrix composite of claim 33, wherein rapidly solidifying comprises the following steps:loading the slurry infiltrated partially densified ceramic matrix composite into an apparatus;spraying a liquid cryogenic material onto the slurry infiltrated partially densified ceramic matrix composite;rapidly solidifying the slurry composition disposed within the slurry infiltrated partially densified ceramic matrix composite; andoptionally, applying ultrasound during rapid solidification.RTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WO39. The partially densified ceramic matrix composite of claim 33, wherein rapidly solidifying comprises the following steps:loading the slurry infiltrated partially densified ceramic matrix composite into an apparatus;charging a slush comprising at least one phase of cryogenic materials into the apparatus; rapidly solidifying one or more liquid phases of the slurry composition within the slurry infiltrated partially densified ceramic matrix composite; andoptionally, applying ultrasound during rapid solidification.

40. The partially densified ceramic matrix composite according to claim 33, wherein the at least one slurry further comprises one or more of the following: a solvent, a binder, a gelling agent, a dispersant, a wetting agent, a pH adjustor, an ice nucleator, a recrystallization inhibitor, and combinations thereof.

41. The partially densified ceramic matrix composite of claim 40, wherein the gelling agent, the binder, or both the gelling agent and the binder comprise any one or more of the following: polyvinyl alcohol (PVA), polyvinyl butyral (PVB), lignosulfonates, starches aluminosilicate, carboxymethylcellulose, methyl cellulose, carbo-ethyl cellulose, hydroxypropyl methyl cellulose, gellan gum, gelatins, pectin, aragose gum, curd Ian gum, xanthium gum, konjac gum, carrageenan gum, alginates, sodium alginate, agar gum, non-ionic copolymer surfactants, and combinations thereof.

42. The partially densified ceramic matrix composite of claim 33, wherein the at least one solid particle comprises any one or more of the following materials: carbon source materials, nitride source materials, boride source materials, oxide source materials, oxide phase precursor materials, metal source materials and metalloid source materials.RTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WO43. The partially densified ceramic matrix composite of claim 42, wherein the carbon source materials comprise any one or more of the following: carbon-based materials, carbide materials, graphite, carbon nanotube, carbon nanofiber, and diamond.

44. The partially densified ceramic matrix composite of claim 43, wherein the carbide materials comprise any one or more of the following: boron carbides, zirconium carbides, hafnium carbides, tantalum carbides, niobium carbides, titanium carbides, molybdenum carbides, tungsten carbides, vanadium carbides, chromium carbides, ytterbium carbides, and yttrium carbides.

45. The partially densified ceramic matrix composite of claim 42, wherein the nitride source materials comprise any one or more of the following: silicon nitrides, titanium nitrides, boron nitrides, zirconium nitrides, hafnium nitrides, niobium nitrides, tantalum nitrides, vanadium nitrides, ytterbium nitrides, and yttrium nitrides.

46. The partially densified ceramic matrix composite of claim 42, wherein the boride source materials comprise any one or more of the following: silicon borides, titanium borides, zirconium borides, hafnium borides, niobium borides, tantalum borides, vanadium borides, molybdenum borides, ytterbium borides, and yttrium borides.

47. The partially densified ceramic matrix composite of claim 42, wherein the oxide source materials comprise any one or more of the following: aluminum oxides, silicon oxides, tantalum oxides, boron oxides, hafnium oxides, zirconium oxides, ytterbium oxides, and yttrium oxides.

48. The partially densified ceramic matrix composite of claim 42, wherein the oxide phase precursor materials comprise one or more of the following: E^Os-SiCh; AEO-AhOa-SiCh, where AE comprises at least one of Be, Ca, Ba and Sr; REO-A Os-SiC , where RE comprises at least one of La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y; and, combinations thereof.RTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WO49. The partially densified ceramic matrix composite of claim 33, wherein depositing comprises one or more of the following techniques: slurry infiltration and chemical vapor infiltration.

50. The partially densified ceramic matrix composite of claim 33, wherein the interface coatingorthe structural support material or both the interface coating and the structural support material comprises one or more of the following materials: carbides, carbon materials, nitrides, borides, and combinations thereof.

51. The partially densified ceramic matrix composite of claim 50, wherein the carbides comprise one or more of the following: silicon carbides, boron carbides, zirconium carbides, hafnium carbides, tantalum carbides, niobium carbides, titanium carbides, molybdenum carbides, tungsten carbides, vanadium carbides, chromium carbides, ytterbium carbides, yttrium carbides, and combinations thereof.

52. The partially densified ceramic matrix composite of claim 50, wherein the carbon materials comprise one or more of the following: pyrolytic carbons, graphite and combinations thereof.

53. The partially densified ceramic matrix composite of claim 50, wherein the nitrides comprise one or more of the following: silicon nitrides, titanium nitrides, boron nitrides, zirconium nitrides, hafnium nitrides, niobium nitrides, tantalum nitrides, vanadium nitrides, ytterbium nitrides, yttrium nitrides, and combinations thereof.

54. The partially densified ceramic matrix composite of claim 50, wherein the borides comprise one or more of the following: silicon borides, titanium borides, zirconium borides,RTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WOhafnium borides, niobium borides, tantalum borides, vanadium borides, ytterbium borides, yttrium borides, and combinations thereof.

55. The partially densified ceramic matrix composite of claim 33, wherein the apparatus comprises any one or more of the following: a vacuum chamber, a slurry infiltration chamber, a freeze dryer, and combinations thereof.

56. The partially densified ceramic matrix composite of claim 33, further comprising densifying the partially densified ceramic matrix composite using any one or more of the following techniques: melt-infiltration, polymer infiltration and pyrolysis, atomic layer deposition, chemical vapor infiltration, physical vapor deposition, chemical vapor deposition, and combinations thereof.

57. The partially densified ceramic matrix composite of claim 56, wherein melt-infiltrating further comprises melt-infiltrating one or more of the following molten infiltrants: metals, metalloids, metal alloys, metalloid alloys, glasses, and combinations thereof.

58. The partially densified ceramic matrix composite of claim 56, further comprising heat treating a densified ceramic matrix composite.

59. The partially densified ceramic matrix composite of claim 33, wherein drying further comprises evaporating one or more liquid phases of the slurry composition within the slurry infiltrated partially densified ceramic matrix composite.

60. The partially densified ceramic matrix composite of claim 33, wherein drying further comprises sublimating one or more liquid phases of the slurry composition within the slurry infiltrated partially densified ceramic matrix composite.RTX Ref. No.: 183281WO01MWZB Ref. No.: RTXPW-0105-WO61. The partially densified ceramic matrix composite of claim 33, wherein drying further comprises subjecting the solidified partially densified ceramic matrix composite at a temperature of at least room temperature to at least one of the following processes: aging, drying, curing, and combinations thereof.

62. The partially densified ceramic matrix composite of claim 61, wherein aging or drying further comprises at least partially evaporating one or more liquid phases of the slurry composition of the solidified partially densified ceramic matrix composite.

63. The partially densified ceramic matrix composite of claim 62, further comprising curing at least one remaining binder present in the partially densified ceramic matrix composite.

64. The partially densified ceramic matrix composite of claim 62, further comprising crosslinking at least one remaining binder present in the partially densified ceramic matrix composite.

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