Method of fabricating a part out of CMC material

Patent metadata

Field	Value
Publication number	US-9440888-B2
Application number	US-201214361854-A
Country	US
Kind code	B2
Filing date	Nov 22, 2012
Priority date	Nov 30, 2011
Publication date	Sep 13, 2016
Grant date	Sep 13, 2016

Abstract

Fabricating a composite material part comprises the steps of making a consolidated fiber preform, the fibers of the preform being carbon or ceramic fibers that are coated in an interphase formed by at least one layer of pyrolytic carbon (PyC) or of boron-doped carbon (BC). Obtaining a partially densified consolidated fiber preform, where partial densification comprises forming a first matrix phase on the interphase, the first matrix phase comprising a plurality of layers of self-healing material alternating with one or more layers of PyC or of BC. Continuing densification by dispersing carbon and/or ceramic powder within the partially densified consolidated preform and by infiltrating molten silicon or a liquid composition formed for the most part of silicon.

First claim

The invention claimed is:

1. A method of fabricating a part out of composite material having a matrix that is at least partially made of ceramic, the method comprising the steps of:
making a fiber structure, the fibers of the fiber structure being carbon or ceramic fibers;
forming an interphase coating on the fibers, the coating being formed by at least one layer of pyrolytic carbon (PyC) or of boron-doped carbon (BC);
shaping the fiber structure by means of shaping tooling in order to obtain a fiber preform of the part that is to be fabricated;
consolidating the fiber preform in the shaping tooling;
forming a first matrix phase on the interphase, the first matrix phase comprising a plurality of layers of self-healing material alternating with one or more layers of material selected from pyrolytic carbon (PyC) and boron-doped carbon (BC), the plurality of layers of self-healing material and the one or more layers of PyC or BC being obtained by chemical vapor infiltration (CVI) in order to obtain a partially densified consolidated preform; and
after removing the partially densified consolidated preform from the shaping tooling, continuing densification by dispersing carbon powder and/or ceramic powder within the partially densified consolidated preform and by infiltrating molten silicon or a liquid composition formed most of silicon.

2. The method according to claim 1 , wherein the material of each layer of self-healing material in the first matrix phase is selected from an Si—B—C ternary system and boron carbide.

3. The method according to claim 1 , wherein a total thickness of the plurality of layers of self-healing material plus the one or more layer(s) of PyC or BC in the first matrix phase lies in a range 500 nm to 30 μm.

4. The method according to claim 1 , wherein the first matrix phase is finished off with at least one layer of ceramic material that does not contain boron, which layer is formed on a last layer of self-healing material.

5. The method according to claim 4 , wherein said layer of ceramic material that does not contain boron has thickness of at least 500 nm.

6. The method according to claim 4 , wherein said layer of ceramic material that does not contain boron is made of silicon carbide (SiC) or of silicon nitride (Si3N4).

7. The method according to claim 5 , wherein said layer of ceramic material that does not contain boron is made of silicon carbide (SiC) or of silicon nitride (Si3N4).

8. The method according to claim 1 , wherein making the consolidated fiber preform comprises forming the fiber preform by shaping the fiber structure and forming the interphase coating on the fibers of the fiber preform by chemical vapor infiltration, and then forming the first matrix phase, the interphase coating and the first matrix phase being formed to have a total thickness that is sufficient for consolidating the fiber preform.

9. The method according to claim 1 , wherein forming the interphase on the fibers of the fiber preform comprises a first step of forming a first interphase layer and a second step of forming a second interphase layer, the first and second steps being separated by a step of consolidating the fiber preform, consolidation of the fiber preform comprising impregnation with a liquid composition containing a carbon or ceramic precursor resin, shaping the fiber preform in tooling, polymerizing the resin, and transforming the resin into carbon or ceramic, the fiber preform being kept in shape in the shaping tooling at least until the resin has been polymerized.

10. The method according to claim 1 , wherein the fiber preform is formed from a fiber structure made as a single piece by three-dimensional or multilayer weaving.

11. The method according to claim 1 , wherein the carbon and/or ceramic powder is dispersed within the consolidated fiber preform by impregnation with a slip containing the carbon and/or ceramic powder in suspension in a liquid vehicle.

12. The method according to claim 1 , wherein the dispersion of carbon and/or ceramic powder within the consolidated fiber preform is performed by means of a liquid composition containing the carbon and/or ceramic powder dispersed in a carbon or ceramic precursor resin.

13. The method according to claim 1 , wherein the liquid composition formed for the most part of silicon also contains at least one element selected from boron B, titanium Ti, and molybdenum Mo.

Assignees

• Herakles

Inventors

• Bouillon Eric
• Philippe Eric
• Lafond Andre
• Lamouroux Franck

Classifications

• C04B2235/72

  Products characterised by the absence or the low content of specific components, e.g. alkali metal free alumina ceramics · CPC title

• C04B41/85 Primary

  with inorganic materials · CPC title

• C04B2235/5248

  Carbon, e.g. graphite · CPC title

• C04B35/573

  obtained by reaction sintering {or recrystallisation} · CPC title

• C04B41/5024

  Silicates (C04B41/5022 takes precedence; silico-fluorides C04B41/5018) · CPC title