# US 11,441,778 B2 · Article with cooling holes and method of forming the same

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- Number: US 11,441,778 B2
- Document ID: US11441778B2
- Status: Granted
- Kind: B2
- Application number: 16/723,404
- Filed: 2019-12-20
- Published: 2021-06-24
- Granted: 2022-09-13
- Earliest claimed: 2019-12-20
- Assignees: Raytheon Technologies Corporation
- Applicants: United Technologies Corporation
- Inventors: Michael R. Kracum; David C. Jarmon
- Web page: https://patentgrep.com/patent/US11441778B2

## CPC

- F23R 3/005: {Combined with pressure or heat exchangers}
- B32B 18/00: Layered products essentially comprising ceramics, e.g. refractory products
- C04B 35/565: based on silicon carbide
- C04B 35/626: Preparing or treating the powders individually or as batches {(pigments for ceramics C09C1/0009); preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B}
- C04B 35/80: Fibres, filaments, whiskers, platelets, or the like
- C04B 38/06: by burning-out added substances {by burning natural expanding materials or by sublimating or melting out added substances}
- C04B 38/0645: {Burnable, meltable, sublimable materials}
- F01D 5/187: {Convection cooling}
- F01D 5/284: {Selection of ceramic materials}
- F01D 25/005: {Selecting particular materials}
- F01D 25/12: Cooling
- F02C 7/18: the medium being gaseous, e.g. air {(F02C7/125 takes precedence)}
- C04B 2235/3826: Silicon carbides
- C04B 2235/3873: Silicon nitrides, e.g. silicon carbonitride, silicon oxynitride
- C04B 2235/5212: Organic
- C04B 2235/5244: Silicon carbide
- C04B 2235/5248: Carbon, e.g. graphite
- C04B 2235/5256: Two-dimensional, e.g. woven structures
- C04B 2235/614: Gas infiltration of green bodies or pre-forms
- C04B 2235/945: Products containing grooves, cuts, recesses or protusions
- F02K 1/822: {Heat insulating structures or liners, cooling arrangements, e.g. post combustion liners; Infrared radiation suppressors}
- F02K 1/827: {Sound absorbing structures or liners}
- F02K 9/346: {Liners, e.g. inhibitors}
- F05D 2230/21: by casting
- F05D 2230/31: Layer deposition
- F05D 2230/90: Coating; Surface treatment
- F05D 2260/201: by impingement of a fluid
- F05D 2260/202: by film cooling
- F05D 2300/20: Oxide or non-oxide ceramics
- F23R 2900/00018: Manufacturing combustion chamber liners or subparts
- F23R 2900/03042: Film cooled combustion chamber walls or domes
- 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)
- B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- 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
- F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D)
- F02C: GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS (construction of turbines F01D; jet-propulsion plants F02K; construction of compressors or fans F04; generating combustion products of high pressure or high velocity F23R; using gas turbines in compression refrigeration plants F25B11/00)
- F02K: JET-PROPULSION PLANTS (features of jet-propulsion plants common to gas-turbine plants, air intakes or fuel supply control of air-breathing jet-propulsion plants F02C7/00, F02C9/00)
- F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS

## Abstract

A method of making an ceramic article according to an exemplary embodiment of this disclosure, among other possible things includes arranging fiber plies into a preform, inserting one or more sacrificial springs to the preform, infiltrating the preform with a matrix material to form an article, and thermally degrading the one or more sacrificial springs to form cooling holes. A ceramic article and a gas turbine engine component are also disclosed.

## Claims

### Claim 1

A method of making a ceramic article, comprising:
arranging fiber plies to form a preform;
after forming the preform, inserting one or more sacrificial springs to the preform;
infiltrating the preform with a matrix material to form an article; and
thermally degrading the one or more sacrificial springs to form cooling holes.

### Claim 2 (depends on 1)

The method of claim 1, wherein the one or more sacrificial springs comprise graphite fibers in an epoxy matrix.

### Claim 3 (depends on 2)

The method of claim 2, wherein the epoxy matrix has a carbon yield of between about 30-50 wt. % upon thermal degradation.

### Claim 4 (depends on 1)

The method of claim 1, wherein the one or more sacrificial springs are inserted by being screwed into the preform.

### Claim 5 (depends on 1)

The method of claim 1, wherein the one or more sacrificial springs are inserted such that an axis of the one or more sacrificial springs is perpendicular to a plane of the fiber plies.

### Claim 6 (depends on 1)

The method of claim 1, wherein the one or more sacrificial springs displace fibers in the plies during insertion.

### Claim 7 (depends on 1)

The method of claim 1, wherein the one or more sacrificial springs are inserted through an entire thickness of the preform such that the one or more sacrificial springs meet or extend through opposed faces of the preform.

### Claim 8 (depends on 1)

The method of claim 1, wherein the infiltrating is by chemical vapor infiltration.

### Claim 9 (depends on 8)

The method of claim 8, wherein non-carbon elements of the one or more sacrificial springs vaporize during the infiltration.

### Claim 10 (depends on 1)

The method of claim 1, further comprising providing a sacrificial sheet in the preform prior to inserting the one or more sacrificial springs into the preform, and thermally degrading the sacrificial sheet after the infiltration to form a gap.

### Claim 11 (depends on 10)

The method of claim 10, wherein the step of thermally degrading the sacrificial sheet is simultaneous with the step of thermally degrading the sacrificial sheet.

### Claim 12 (depends on 1)

The method of claim 1, further comprising compressing the preform prior to the infiltration.

### Claim 13 (depends on 12)

The method of claim 12, wherein a fiber content of the preform before compressing is between about 5-20 vol. % and the fiber content of the preform after the compressing is between about 20-50 vol. %.

### Claim 14 (depends on 1)

The method of claim 1, further comprising:
inserting carbon inserts into the cooling holes at a face of the article;
applying a coating to the face; and
thermally degrading the carbon inserts.

### Claim 15 (depends on 1)

The method of claim 1, further comprising forming the one or more sacrificial springs by pultrusion.

### Claim 16 (depends on 1)

The method of claim 1, wherein prior to step of arranging the plies to form the preform, applying an interface coating to one or more of the plies.

### Claim 17 (depends on 1)

The method of claim 1, wherein at least one of the one or more sacrificial springs include a sharpened end configured to facilitate insertion of the at least one sacrificial spring into the preform.

### Claim 18 (depends on 1)

The method of claim 1, further comprising the step of forming the one or more sacrificial springs by:
providing a rod; and
forming the rod into a helical shape.

### Claim 19 (depends on 18)

The method of claim 18, wherein the rod has a diameter between about 0.38 and 1.02 mm (0.015 and 0.040 inches).

### Claim 20 (depends on 10)

The method of claim 10, wherein the sacrificial sheet is arranged with the fiber plies while forming the preform.