# US 12,006,837 B2 · Ceramic matrix composite article and method of making the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,006,837 B2 - Document ID: US12006837B2 - Status: Granted - Kind: B2 - Application number: 17/587,764 - Filed: 2022-01-28 - Published: 2023-08-03 - Granted: 2024-06-11 - Earliest claimed: 2022-01-28 - Assignees: Rtx Corporation - Applicants: Raytheon Technologies Corporation - Inventors: Bryan P. Dube; David A. Litton - Web page: https://patentgrep.com/patent/US12006837B2 ## CPC - F01D 5/186: {Film cooling (F01D5/187 takes precedence)} - F01D 5/282: {Selecting composite materials, e.g. blades with reinforcing filaments} - F01D 5/284: {Selection of ceramic materials} - F01D 5/288: {Protective coatings for blades} - F01D 9/023: {Transition ducts between combustor cans and first stage of the turbine in gas-turbine engines; their cooling or sealings} - F23R 3/007: {constructed mainly of ceramic components} - F23R 3/06: Arrangement of apertures along the flame tube - F05D 2230/90: Coating; Surface treatment - F05D 2240/11: Shroud seal segments - F05D 2240/81: Cooled platforms - F05D 2260/202: by film cooling - F05D 2260/232: characterized by the cooling medium - F05D 2300/6033: Ceramic matrix composites [CMC] - F05D 2300/611: Coating - F23R 2900/03042: Film cooled combustion chamber walls or domes - Y02T 50/60: Efficient propulsion technologies, e.g. for aircraft - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) - F23R: GENERATING COMBUSTION PRODUCTS OF HIGH PRESSURE OR HIGH VELOCITY, e.g. GAS-TURBINE COMBUSTION CHAMBERS (fluidised bed combustion apparatus specially adapted for operation at superatmospheric pressures F23C10/16) - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A ceramic matrix composite component includes a ceramic matrix composite wall; a coating disposed on the wall; and a cooling hole formed in the wall. The cooling hole has a metering section defined along a first axis and a diffuser section defined along a second axis that is offset from the first axis. The cooling hole has a total length defined along the first axis, the total length being the sum of a length of the metering portion and a length of the diffuser portion. The length of the metering portion is between about 40 percent and about 85 percent of the total length. A ceramic matrix composite airfoil and a method of applying a coating to a ceramic matrix composite component are also disclosed. ## Claims ### Claim 1 A ceramic matrix composite component, comprising: a ceramic matrix composite wall; a coating disposed on the wall; and a cooling hole formed in the wall, the cooling hole having a metering section defined along a first axis and a diffuser section defined along a second axis that is offset from the first axis, and wherein the cooling hole has a total length defined along the first axis, the total length being the sum of a length of the metering portion and a length of the diffuser portion, wherein the coating takes up less than about 50% of a volume of the diffuser portion. ### Claim 2 (depends on 1) The ceramic matrix composite component of claim 1, wherein the length of the diffuser section is greater than a thickness of the coating. ### Claim 3 (depends on 2) The ceramic matrix composite component of claim 2, wherein a ratio of the length of the diffuser section to the thickness of the coating is at least about 3. ### Claim 4 (depends on 1) The ceramic matrix composite component of claim 1, wherein the length of the metering portion along the first axis is between about 60 percent and about 70 percent of the total length. ### Claim 5 (depends on 1) The ceramic matrix composite component of claim 1, wherein a size of the offset is equivalent to a difference between a diameter of the diffuser section and a diameter of the metering section. ### Claim 6 (depends on 5) The ceramic matrix composite component of claim 5, wherein a ratio of the diameter of the diffuser section to the diameter of the metering section is between about 1.25 and about 2.5. ### Claim 7 (depends on 6) The ceramic matrix composite component of claim 6, wherein the metering portion is free from the coating. ### Claim 8 (depends on 1) The ceramic matrix composite component of claim 1, wherein the length of the metering portion is between about 40 percent and about 85 percent of the total length. ### Claim 9 A ceramic matrix composite airfoil, comprising: a ceramic matrix composite wall defining an inner cavity; a coating disposed on an outer surface of the wall; and a cooling hole formed in the wall, the cooling hole having a metering portion in fluid communication with the inner cavity and defined along a first axis, and a diffuser section defined along a second axis that is offset from the first axis, and wherein the cooling hole has a total length defined along the first axis, the total length being the sum of a length of the metering portion and a length of the diffuser section, wherein the coating takes up less than about 50% of a volume of the diffuser portion. ### Claim 10 (depends on 9) The ceramic matrix composite airfoil of claim 9, wherein the length of the diffuser section is greater than a thickness of the coating. ### Claim 11 (depends on 10) The ceramic matrix composite airfoil of claim 10, wherein a ratio of the length of the diffuser section to the thickness of the coating is at least about three. ### Claim 12 (depends on 9) The ceramic matrix composite airfoil of claim 9, wherein the length of the metering portion along the first axis is between about 60 percent and about 70 percent of the total length. ### Claim 13 (depends on 9) The ceramic matrix composite airfoil of claim 9, wherein the second axis is spaced from the first axis by an offset, and a size of the offset is equivalent to a difference between a diameter of the diffuser section and a diameter of the metering section. ### Claim 14 (depends on 13) The ceramic matrix composite airfoil of claim 13, wherein a ratio of the diameter of the diffuser section to the diameter of the metering section is between about 1.25 and about 2.5. ### Claim 15 (depends on 9) The ceramic matrix composite airfoil of claim 9, wherein the metering section is free from the coating. ### Claim 16 (depends on 9) The ceramic matrix composite airfoil of claim 9, wherein the length of the metering portion is between about 40 percent and about 85 percent of the total length. ### Claim 17 A method of applying a coating to a ceramic matrix composite component, comprising: providing a ceramic matrix composite component having a cooling hole therethrough, the cooling hole having a metering section in fluid communication with the inner cavity and defined along a first axis, and a diffuser section defined along a second axis that is offset from the first axis; and applying a coating to a surface of the ceramic matrix composite in a direction of the offset, wherein the coating takes up less than about 50% of a volume of the diffuser portion. ### Claim 18 (depends on 17) The method of claim 17, wherein the metering portion is free from the coating after the applying step. ### Claim 19 (depends on 17) The method of claim 17, wherein the cooling hole has a total length defined along the first axis, the total length being the sum of a length of the metering section and a length of the diffuser portion, and the length of the metering section is between about 40 percent and about 85 percent of the total length.