Process for the production of a carbon-containing composite material part protected against oxidation

Claim 2

In a process for the production of a carbon-containing composite material part, which is protected against oxidation, in which a carbon-fibre containing fibrous preform is densified with the carbon-containing densification material, a refractory material is formed in the outer surface of the densified preform, and cracks in the outer coating filled, the improvement wherein: (a) the fibrous preform is formed by superimposing layers of carbon-containing fibres, the fibres of each layer being parallel to one another and the N outermost layers of said superimposition, with N being an integral ≧2, being arranged in such a way that their fibres are only oriented in accordance with a first or a second direction (x,y), while the internal layers of said superimposition being arranged in such a way that their fibres are oriented with a third direction, the first and second direction being perpendicular to one another and contained in a same plane, the third direction being also contained in said plane; (b) the fibrous preform is densified by a carbon-containing material; (c) an outer stable refractory carbonitride or carbide coating is formed on the surface of the densified preform by chemically reacting, at a temperature above ambient temperature, the N-1 outermost densified layers of the densified preform with at least one chemical compound precursor of said carbide or carbonitride; (d) the assembly obtained in (c) is allowed to cool in order to form in the outer coating cracks in the thickness direction of said coating and issuing towards to the outside of the part, said cracks being oriented in first and second directions and defining between them parallelepipedic blocks (30) of said carbide or carbonitride; and (e) filling the cracks with a refractory carbide or carbonitride.

Claim 3

In a process for the production of a carbon-containing composite material part, which is protected against oxidation, in which a carbon-fibre containing fibrous preform is densified with a carbon-containing densification material, a refractory material is formed in the outer surface of the densified preform, and cracks in the outer coating filled, the improvement wherein: (a) the fibrous preform is formed by superimposing layers of carbon-containing fibres, the fibres of each layer being parallel to one another and the N outermost layers of said superimposition, with N being an integral ≧2, being arranged in such a way that their fibres are only oriented in accordance with a first or a second direction (x,y), while the internal layers of said superimposition being arranged in such a way that their fibres are oriented with a third direction, the first and second directions being perpendicular to one another and contained in a same plane, the third direction being also contained in said plane; (b) the fibrous preform is densified by a carbon-containing material; (c) an outer stable refractory carbonitride or carbide coating is formed on the surface of the densified preform by chemically reacting, at a temperature above ambient temperature, the N-1 outermost densified layers of the densified preform with at least one chemical compound precursor of said carbide or carbonitride; (d) the assembly obtained in (c) is allowed to cool in order to form in the outer coating cracks in the thickness direction of said coating and issuing towards the outside of the part, these cracks being oriented in first and second directions and defining between them parallelepipedic blocks (30) of said carbide or carbonitride; (e) the assembly obtained in (c) in allowed to cool in order to form in the outer coating cracks in the thickness direction of said coating and issuing towards the outside of the part, these cracks being oriented in first and second directions and defining between them parallelepipedic blocks (30) of said carbide or carbonitride, the cracks are filled by a refractory carbide or carbonitride; and (f) depositing a layer of refractory oxide on the outer coating and filled cracks.

Claim 4

In a process for the production of a carbon-containing composite material part, which is protected against oxidation, in which a carbon-fibre containing fibrous preform is densified with a carbon-containing densification material, a refractory material is formed in the outer surface of the densified preform, and cracks in the outer coating filled, the improvement wherein: (a) the fibrous preform is formed by superimposing layers of carbon-containing fibres, the fibres of each layer being parallel to one another and the N outermost layers of said superimposition, with N being an integral ≧2, being arranged in such a way that their fibres are only oriented in accordance with a first or a second direction (x,y), while the internal layers of said superimposition being arranged in such a way that their fibres are oriented with a third direction, the first and second directions being perpendicular to one another and contained in a same plane, the third direction being also contained in said plane; (b) the fibrous preform is densified by a carbon-containing material; (c) an outer stable refractory carbonitride or carbide coating is formed on the surface of the densified preform by chemically reacting, at a temperature above ambient temperature, the N-1 outermost densified layers of the densified preform with at least one chemical compound precursor of said carbide or carbonitride; (d) the assembly obtained in (c) is allowed to cool in order to form in the outer coating cracks in the thickness direction of said coating and issuing towards the outside of the part, these cracks being oriented in first and second directions and defining between them parallelepipedic blocks (30) of said carbide or carbonitride; (e) the assembly obtained in (c) in allowed to cool in order to form in the outer coating cracks in the thickness direction of said coating and issuing towards the outside of the part, these cracks being oriented in first and second directions and defining between them parallelepipedic blocks (30) of said carbide or carbonitride, the cracks are filled by a refractory carbide or carbonitride; and (f) depositing a layer of refractory oxide on the outer coating and filled cracks.

Claim 5

In a process for the production of carbon-containing composite material part, which is protected against oxidation, in which a carbon-fibre containing fibrous preform is densified with a carbon-containing densification material, a refractory material is formed in the outer surface of the densified preform, and cracks in the outer coating filled, the improvement wherein: (a) the fibrous preforms is formed by superimposing layers of carbon-containing fibres, the fibres of each layer being parallel to one another and the N outermost layer of said superimposition, with N being an integral ≧2, being arranged in such a way that their fibres are only oriented in accordance with a first and second direction (x,y), while the internal layers of said superimposition being arranged in such a way that their fibres are oriented with a third direction, the first and second directions being perpendicular to one another and contained in a same plane, the third direction being also contained in said plane; (b) the fibrous preform is densified by a carbon-containing material; (c) an outer stable refractory carbonitride or carbide coating is formed on the surface of the densified preform by chemically reacting, at a temperature above ambient temperature, the N-1 outermost densified layers of the densified preform with at least one chemical compound constituting precursor of said carbide or carbonitride; (d) the assembly obtained in (c) is allowed to cool in order to form in the outer coating cracks in the thickness direction of said coating and issuing towards the outside of the part, these cracks being oriented in first and second directions and defining between them parallelepipedic blocks (30) of said carbide or carbonitride; (e) filling the cracks with a refractory carbide or carbonitride; and (f) depositing a layer of refractory oxide on the outer coating and filling cracks.

Claim 6

In a process for the production of carbon-containing composite material part, which is protected against oxidation, in which a carbon-fibre containing fibrous preform is densified with a carbon-containing densification material, a refractory material is formed in the outer surface of the densified preform, and cracks in the outer coating filled, the improvement wherein: (a) the fibrous preforms is formed by superimposing layers of carbon-containing fibres, the fibres of each layer being parallel to one another and the N outermost layer of said superimposition, with N being an integral ≧2, being arranged in such a way that their fibres are only oriented in accordance with a first and second direction (x,y), while the internal layers of said superimposition being arranged in such a way that their fibres are oriented with a third direction, the first and second directions being perpendicular to one another and contained in a same plane, the third direction being also contained in said plane; (b) the fibrous preform is densified by a carbon-containing material; (c) an outer stable refractory carbonitride or carbide coating is formed on the surface of the densified preform by chemically reacting, at a temperature above ambient temperature, the N-1 outermost densified layers of the densified preform with at least one chemical compound constituting precursor of said carbide or carbonitride; (d) the assembly obtained in (c) is allowed to cool in order to form in the outer coating cracks in the thickness direction of said coating and issuing towards the outside of the part, these cracks being oriented in first and second directions and defining between them parallelepipedic blocks (30) of said carbide or carbonitride; (e) filling the cracks with a refractory carbide or carbonitride; and (f) depositing a layer of refractory oxide on the outer coating and filling cracks.

Claim 7

In a process according to claim 1, the improvement wherein the thickness of the carbide or carbonitride layer is less than the thickness of material and underlying carbon-containing fibres not transformed into carbide or carbonitride.

Claim 8

In a process according to claim 1, the improvement wherein the layers of fibres located below the outermost N layers are arranged in such a way that the part has quasi-isotropic or specific mechanical properties in accordance with the said plane.

Claim 9

In a process according to claim 1, the improvement wherein the chemical compound is silicon or a compound of silicon, and the outer coating is silicon carbide.

Claim 10

In a process according to claim 1, the improvement wherein the fibres are carbon fibres.

Claim 11

In a process according to claim 1, the improvement wherein the densification material is essentially carbon.

Claim 12

In a process according to claim 1, the improvement wherein the desification material is carbon doped by an oxidation retardant.

Claim 13

In a process according to claim 1, the improvement wherein N=3.

Claim 14

In a process according to claim 10, the improvement wherein the outermost first, second and third layers are positioned in such a way that the fibres of the second layer are perpendicular to those of the first and third layers, and the second layer is interposed between the first and third layers.

Claim 15

In a process according to claim 1, the improvement wherein the cracks are filled by chemical vapour phase deposition of a refractory carbide or carbonitride in the cracks.

Claim 16

In a process according to claim 1, the improvement wherein the cracks are initially filled, in part, by first depositing a layer of a refractory oxide.

Claim 17

In a process according to claim 1, the improvement wherein the fibres of each layer are coated with silicon carbonitride or carbide prior to the superimposing of the layers.

Claim 18

In a process according to claim 2, the improvement wherein the thickness of the carbide or carbonitride layer is less than the thickness of the carbide or carbonitride layer is less than the thickness of material and underlying carbon-containing fibres not transformed into carbide or carbonitride.

Claim 19

In a process according to claim 2, the improvement wherein the layers of fibres located below the outermost N layers are arranged in such a way that the part has quasi-isotropic or specific mechanical properties in accordance with the said plane.

Claim 20

In a process according to claim 2, the improvement wherein the chemical compound is silicon or a compound of silicon, and the outer coating is silicon carbide.

Claim 21

In a process according to claim 2, the improvement wherein the fibres are carbon fibres.

Claim 22

In a process according to claim 2, the improvement wherein the densification material is essentially carbon.

Claim 23

In a process according to claim 2, the improvement wherein the densification material is carbon doped by an oxidation retardant.

Claim 24

In a process according to claim 2, the improvement wherein N=3.

Claim 25

In a process according to claim 21, the first, second and third layers are positioned in such a way that the fibres of the second layer are perpendicular to those of the first and third layers, and the second layer is interposed between the first and third layers.

Claim 26

In a process according to claim 2, the improvement wherein the cracks are filled by chemical vapour phase deposition of a refractory carbide or carbonitride in the cracks.

Claim 27

In a process according to claim 2, the improvement wherein the cracks are initially filled, in part, by first depositing a layer of a refractory oxide.

Claim 28

In a process according to claim 2, the improvement wherein the fibres of each layer are coated with silicon carbonitride or carbide prior to the superimposing of the layers.

Claim 29

In a process according to claim 3, the improvement wherein the thickness of the carbide or carbonitride layer is less than the thickness of material and underlying carbon-containing fibres not transformed into carbide or carbonitride.

Claim 30

In a process according to claim 3, the improvement wherein the layers of fibres located below the outermost N layers are arranged in such a way that the part has quasi-isotropic or specific mechanical properties in accordance with the said plane.

Claim 31

In a process according to claim 3, the improvement wherein the chemical compound is silicon or a compound of silicon, and the outer coating is silicon carbide.

Claim 32

In a process according to claim 3, the improvement wherein the fibres are carbon fibres.

Claim 33

In a process according to claim 3, the improvement wherein the densification material is essentially carbon.

Claim 34

In a process according to claim 3, the improvement wherein the densification material is carbon doped by an oxidation retardant.

Claim 35

In a process according to claim 3, the improvement wherein N=3.

Claim 36

In a process according to claim 32, the improvement wherein the outermost first, second and third layers are positioned in such a way that the fibres of the second layer are perpendicular to those of the first and third layers, and the second layer is interposed between the first and third layers.

Claim 37

In a process according to claim 3, the improvement wherein the cracks are filled by chemical vapour phase deposition of a refractory carbide or carbonitride in the cracks.

Claim 38

In a process according to claim 3, the improvement wherein the cracks are initially filled, in part, by first depositing a layer of a refractory oxide.

Claim 39

In a process according to claim 3, the improvement wherein the fibres of each layer are coated with silicon carbonitride or carbide prior to the superimposing of the layers.