# US 11,028,020 B2 · Ceramic composition and method of making the composition > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,028,020 B2 - Document ID: US11028020B2 - Status: Granted - Kind: B2 - Application number: 16/143,319 - Filed: 2018-09-26 - Published: 2020-03-26 - Granted: 2021-06-08 - Earliest claimed: 2018-09-26 - Assignees: The Boeing Company - Applicants: The Boeing Company - Inventors: Tab Hunter Crooks; MaryAnn S. Muench - Web page: https://patentgrep.com/patent/US11028020B2 ## CPC - C04B 35/62625: {Wet mixtures} - C04B 37/003: {by means of an interlayer consisting of a combination of materials selected from glass, or ceramic material with metals, metal oxides or metal salts} - C04B 35/10: based on aluminium oxide - C04B 35/14: based on silica - C04B 35/46: based on titanium oxides or titanates (containing also zirconium or hafnium oxides, zirconates or hafnates C04B35/49) - C04B 35/48: based on zirconium or hafnium oxides, zirconates, {zircon} or hafnates - C04B 35/62655: {Drying, e.g. freeze-drying, spray-drying, microwave or supercritical drying} - C04B 35/628: Coating the powders {or the macroscopic reinforcing agents} - C04B 35/653: Processes involving a melting step - C04B 2235/3217: Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina - C04B 2235/3232: Titanium oxides or titanates, e.g. rutile or anatase - C04B 2235/3244: Zirconium oxides, zirconates, hafnium oxides, hafnates, or oxide-forming salts thereof - C04B 2235/3427: Silicates other than clay, e.g. water glass - C04B 2235/442: Carbonates - C04B 2235/447: Phosphates or phosphites, e.g. orthophosphate or hypophosphite - C04B 2235/5208: Fibers - C04B 2235/5216: Inorganic - C04B 2235/522: Oxidic - C04B 2235/5224: Alumina or aluminates - C04B 2235/5228: Silica and alumina, including aluminosilicates, e.g. mullite - C04B 2235/5232: Silica or silicates other than aluminosilicates, e.g. quartz - C04B 2235/5236: Zirconia - C04B 2235/526: characterised by the length of the fibers - C04B 2235/5264: characterised by the diameter of the fibers - C04B 2235/606: Drying - C04B 2235/96: Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance - C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE ## Abstract A method of making a ceramic composite comprises forming a wet ceramic composition comprising a plurality of discrete ceramic components and a fluxing agent dissolved in a solvent. At least a portion of the solvent is removed from the wet ceramic composition to form a dried ceramic composition comprising the plurality of discrete ceramic components coated with the fluxing agent. The dried ceramic composition is sintered to form the ceramic composite, the sintering being carried out at a sinter temperature sufficient to fuse the discrete ceramic components at bridging sites formed where two or more of the discrete ceramic components coated with fluxing agent are in physical contact. ## Claims ### Claim 1 A method of making a ceramic composite, the method comprising: forming a wet ceramic composition comprising a plurality of discrete ceramic components and a fluxing agent dissolved in a solvent; removing at least a portion of the solvent from the wet ceramic composition to form a dried ceramic composition comprising the plurality of discrete ceramic components coated with the fluxing agent; and sintering the dried ceramic composition to form the ceramic composite, the sintering being carried out at a sinter temperature sufficient to fuse the discrete ceramic components at bridging sites formed where two or more of the discrete ceramic components coated with fluxing agent are in physical contact, wherein the number of bridging sites per unit volume of the ceramic composite is greater than for a ceramic second composite, if the ceramic second composite were to be made using a similar process with the same ingredients in the same amounts by weight as the ceramic composite, except that the only fluxing agent employed in the ceramic second composite was a non-soluble fluxing agent. ### Claim 2 (depends on 1) The method of claim 1, wherein the fluxing agent is chosen from lithium metaborate, carbonates, borates, phosphates, silicates, and combinations thereof. ### Claim 3 (depends on 1) The method of claim 1, wherein the fluxing agent is lithium metaborate. ### Claim 4 (depends on 1) The method of claim 1, wherein the amount of soluble fluxing agent in the wet ceramic composition ranges from about 0.5 to about 2 weight percent based on the total weight of discrete ceramic components. ### Claim 5 (depends on 1) The method of claim 1, wherein the solvent comprises a compound chosen from water, a non-aqueous solvent, and mixtures thereof. ### Claim 6 (depends on 1) The method of claim 1, wherein the plurality of discrete ceramic components comprise a ceramic oxide. ### Claim 7 (depends on 6) The method of claim 6, wherein the ceramic oxide comprises a material selected from titania, silica, alumina, zirconia, and combinations thereof. ### Claim 8 (depends on 1) The method of claim 1, wherein the plurality of discrete ceramic components are in a form of particles or fibers. ### Claim 9 (depends on 1) The method of claim 1, wherein the sinter temperature ranges from about 2200° F. to about 2700° F. ### Claim 10 (depends on 1) The method of claim 1, wherein the wet ceramic composition does not include a non-soluble fluxing agent. ### Claim 11 (depends on 1) The method of claim 1, wherein the wet ceramic composition further comprises at least one non-soluble fluxing agent. ### Claim 12 (depends on 11) The method of claim 11, wherein the amount of non-soluble fluxing agent in the wet ceramic composition ranges from about 0.3 to about 2 weight percent based on the total weight of discrete ceramic components. ### Claim 13 A ceramic composite, comprising: a plurality of discrete ceramic components comprising (i) one or more ceramic compounds and (ii) one or more soluble fluxing agent atoms incorporated into at least a surface of the discrete ceramic components, the discrete ceramic components being fused together at bridging sites located where two or more of the discrete ceramic components are in physical contact, wherein the number of bridging sites per unit volume of the ceramic composite is greater than for a ceramic second composite, if the ceramic second composite were to be made using a similar process with the same ingredients in the same amounts by weight as the ceramic composite, except that the only fluxing agent employed in the ceramic second composite was a non-soluble fluxing agent. ### Claim 14 (depends on 13) The ceramic composite of claim 13, wherein the fluxing agent atoms comprise lithium. ### Claim 15 (depends on 13) The ceramic composite of claim 13, wherein the plurality of discrete ceramic components comprise a ceramic oxide. ### Claim 16 (depends on 15) The ceramic composite of claim 15, wherein the ceramic oxide comprises a material selected from titania, silica, alumina, zirconia, and combinations thereof. ### Claim 17 (depends on 15) The ceramic composite of claim 15, wherein the fluxing agent atoms comprise lithium atoms bonded to the ceramic oxide. ### Claim 18 (depends on 15) The ceramic composite of claim 15, wherein the plurality of discrete ceramic components are in the form of particles or fibers. ### Claim 19 (depends on 13) The ceramic composite of claim 13, wherein the bridging sites are formed without using a non-soluble fluxing agent. ### Claim 20 (depends on 13) The ceramic composite of claim 13, wherein the wet ceramic composition further comprises at least one non-soluble fluxing agent. ### Claim 21 A method of strengthening a ceramic composite, the method comprising: forming a wet ceramic composition comprising a plurality of discrete ceramic components and a fluxing agent dissolved in a solvent; removing at least a portion of the solvent from the wet ceramic composition to form a dried ceramic composition comprising the plurality of discrete ceramic components coated with the fluxing agent; and sintering the dried ceramic composition to form the ceramic composite, the sintering being carried out at a sinter temperature sufficient to fuse the discrete ceramic components at bridging sites formed where two or more of the discrete ceramic components coated with fluxing agent are in physical contact, the ceramic composite having a first tensile strength that is greater than a second tensile strength of a second ceramic composite, if the second ceramic composite were to be made using a similar process with the same ingredients in the same amounts by weight as the ceramic composite having the first tensile strength, except that the fluxing agent of the second ceramic composite was non-soluble and remained in a solid form that was not dissolved in a solvent while making the second ceramic composite. ### Claim 22 (depends on 21) The method of claim 21, wherein the first tensile strength is increased by a range of 10% to 40% compared to the second tensile strength, where both the first tensile strength and the second tensile strength are measured by the ASTM D-1623-type B testing procedure using a test specimen in the through-the-thickness (“TTT”) orientation. ### Claim 23 (depends on 4) The method of claim 4, wherein the fluxing agent is chosen from lithium metaborate, carbonates, borates, phosphates, silicates, and combinations thereof, and further wherein 80% to 100% by weight of the fluxing agent is dissolved in the solvent. ### Claim 24 (depends on 23) The method of claim 23, wherein the plurality of discrete ceramic components are fibers comprising a ceramic oxide. ### Claim 25 (depends on 24) The method of claim 24, wherein the fluxing agent is lithium metaborate. ### Claim 26 (depends on 25) The method of claim 25, wherein the wet ceramic composition further comprises at least one non-soluble fluxing agent in addition to the fluxing agent dissolved in the solvent, the non-soluble fluxing agent being a granular fluxing agent that does not appreciably dissolve in the solvent so that 80% to 100% by weight of the non-soluble fluxing agent remains in solid form in the wet ceramic composition prior to sintering. ### Claim 27 (depends on 13) The ceramic composite of claim 13, wherein the ceramic composite has a first tensile strength that is greater than a second tensile strength of the ceramic second composite, wherein the first tensile strength is increased by a range of 10% to 40% compared to the second tensile strength, where both the first tensile strength and the second tensile strength are measured by the ASTM D-1623-type B testing procedure using a test specimen in the through-the-thickness (“TTT”) orientation.