# US 11,897,816 B2 · Method for manufacturing a CMC part

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 11,897,816 B2
- Document ID: US11897816B2
- Status: Granted
- Kind: B2
- Application number: 17/054,676
- Filed: 2019-05-15
- Published: 2021-03-18
- Granted: 2024-02-13
- Earliest claimed: 2018-05-15
- Assignees: Safran; Safran Ceramics; Safran Aircraft Engines
- Applicants: Safran; Safran Ceramics; Safran Aircraft Engines
- Inventors: Michaël Podgorski; Bruno Jacques Gérard Dambrine; Emilie Chantal Gisèle Mendez; Wen Zhang; Yvan Rappart; Charles Leleu
- Web page: https://patentgrep.com/patent/US11897816B2

## CPC

- C04B 35/565: based on silicon carbide
- B22C 7/02: Lost patterns
- B22C 9/04: Use of lost patterns
- C04B 35/185: Mullite {3Al2O3-2SiO2}
- C04B 35/573: obtained by reaction sintering {or recrystallisation}
- C04B 35/583: based on boron nitride
- C04B 35/584: based on silicon nitride
- C04B 35/62868: {Boron nitride}
- C04B 35/62873: {Carbon}
- C04B 35/62897: {Coatings characterised by their thickness}
- C04B 35/78: containing non-metallic materials
- C04B 35/80: Fibres, filaments, whiskers, platelets, or the like
- C04B 41/009: {characterised by the material treated}
- C04B 41/459: {Temporary coatings or impregnations (C04B40/04 takes precedence)}
- C04B 41/47: Oils, fats or waxes {natural resins}
- C04B 41/5096: {Silicon (C04B35/573 takes precedence)}
- C04B 41/52: Multiple coating or impregnating {multiple coating or impregnating with the same composition or with compositions only differing in the concentration of the constituents, is classified as single coating or impregnation}
- C04B 41/89: for obtaining at least two superposed coatings having different compositions
- F01D 5/288: {Protective coatings for blades}
- C04B 2235/422: Carbon
- C04B 2235/428: Silicon
- C04B 2235/5244: Silicon carbide
- C04B 2235/5248: Carbon, e.g. graphite
- C04B 2235/5252: having a specific pre-form
- C04B 2235/5436: micrometer sized, i.e. from 1 to 100 micron
- C04B 2235/5445: submicron sized, i.e. from 0,1 to 1 micron
- C04B 2235/6028: Shaping around a core which is removed later
- C04B 2235/614: Gas infiltration of green bodies or pre-forms
- C04B 2235/616: Liquid infiltration of green bodies or pre-forms
- F05D 2260/95: Preventing corrosion
- F05D 2300/6033: Ceramic matrix composites [CMC]
- F05D 2300/611: Coating
- 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
- B22C: FOUNDRY MOULDING (moulding refractory materials in general B28B)
- F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D)
- F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS

## Abstract

A process for manufacturing a part made of a ceramic matrix composite material, includes coating an outer surface of a porous preform with a layer of a fugitive material to form a model of the part to be obtained, the fugitive material being wax or resin, the fugitive material layer in the model not exceeding the highest peak of surface undulations of the preform, and ceramic and/or carbon particles being present in the porosity of the preform, coating the model formed with a ceramic powder composition, heat treating the coated model to remove the fugitive material and form a ceramic shell mold by sintering of the ceramic powder composition, introducing a molten composition including silicon into the shell mold to obtain the part in the shell mold, the molten composition infiltrating the porosity of the preform to form the ceramic matrix, and separating the shell mold from the part obtained.

## Claims

### Claim 1

A process for manufacturing a part made of a ceramic matrix composite material, comprising:
coating an outer surface of a porous preform with a layer of a fugitive material to form a model of the part to be obtained, the fugitive material being a wax or a resin, the fugitive material layer in the model not exceeding a highest peak of surface undulations of the porous preform, and ceramic and/or carbon particles being present in the porosity of the porous preform,
coating the model formed with a ceramic powder composition,
heat treating the coated model to remove the fugitive material and form a ceramic shell mold by sintering of the ceramic powder composition,
introducing a molten composition comprising silicon into the shell mold to obtain the part in the shell mold, the molten composition infiltrating the porosity of the porous preform to form the ceramic matrix, and
separating the shell mold from the part obtained.

### Claim 2 (depends on 1)

The process as claimed in claim 1, wherein the ceramic powder composition comprises: a mullite powder, a silicon carbide powder, a silicon nitride powder, a boron nitride powder, or a mixture thereof.

### Claim 3 (depends on 1)

The process as claimed in claim 1, wherein the porous preform is a woven fibrous preform obtained by three-dimensional weaving.

### Claim 4 (depends on 3)

The process as claimed in claim 3, wherein the porous preform is partially densified by a ceramic matrix phase.

### Claim 5 (depends on 1)

The process as claimed in claim 1, wherein the part is a turbomachine part.

### Claim 6

A process for manufacturing a multilayer structure comprising:
manufacturing a part made of ceramic matrix composite material coated with a bonding layer comprising silicon by implementing a process comprising:
coating an outer surface of a porous preform with a layer of a fugitive material in order to form a model of the coated part to be obtained having dimensions of the coated part,
coating the model formed with a ceramic powder composition,
heat treating the coated model to remove the fugitive material and form a ceramic shell mold by sintering of the ceramic powder composition,
introducing a molten composition comprising silicon into the shell mold to obtain the coated part in the shell mold, the molten composition infiltrating the porosity of the porous preform to form the ceramic matrix and covering the outer surface to form the bonding layer, ceramic and/or carbon particles being present in the porosity of the porous preform, and
separating the shell mold from the coated part obtained, and
forming a protective coating on the bonding layer.

### Claim 7 (depends on 6)

The process as claimed in claim 6, wherein the ceramic powder composition comprises: a mullite powder, a silicon carbide powder, a silicon nitride powder, a boron nitride powder, or a mixture of thereof.

### Claim 8 (depends on 6)

The process as claimed in claim 6, wherein the thickness of the fugitive material layer in the model is greater than or equal to 10 μm, said thickness being measured at and from a highest peak of surface undulations of the porous preform.

### Claim 9 (depends on 6)

The process as claimed in claim 6, wherein the fugitive material is a wax or a resin.

### Claim 10 (depends on 6)

The process as claimed in claim 6, wherein the porous preform is a woven fibrous preform obtained by three-dimensional weaving.

### Claim 11 (depends on 6)

The process as claimed in claim 6, wherein the porous preform is partially densified by a ceramic matrix phase.

### Claim 12 (depends on 6)

The process as claimed in claim 6, wherein the coated part is a turbomachine part.

### Claim 13 (depends on 6)

The process as claimed in claim 6, wherein the protective coating is an environmental barrier.