Process for producing sealing components from all-carbon composite material

Process for producing carbon composite components (1) of a large area in relation to the thickness and having an edge (2) and a central part (3), comprising at least one layer of carbon/carbon composite (4) and at least one layer of recompressed expanded graphite (5), said process comprising the steps of:

• (a) establishing a stack (8) of at least one layer of preimpregnate (6) based on a carbon-files lap impregnated with carbonisable resin and of at least one layer of expanded graphite (7);
• (b) compressing the stack;
• and (c) curing the compressed stack by a thermal treatment at high temperature to obtain a sealing carbon composite component (1) with a central part (3) having a high deformation level and/or with an edge (2) providing self-bonding of the layers of the components, wherein in step (a) the stack (8) is prepared of at least one layer of preimpregnate (6) comprising a sheet, optionally deformable, based on carbon files or a precursor of carbon fibres, of an area at least equal to that of the central part, and of at least one layer of expanded graphite (7a) of a specific gravity of between 0.03 and 0.06 and of an area at least equal to an area of a projection of the said component on the mid-plane (11), and wherein in step (b) the stack (8) is compressed between a punch (9) and a die (10) of a press under a pressure of between 2.5 and 15 MPa and at a temperature of between 50.degree. and 200.degree. C., in such a way that the thickness of the edge (2) is at least equal to that of the central part (3) and the specific gravity of the expanded graphite is between 0.3 and 0.6 for the edge and between 1 and 1.5 for the central part, and wherein in step (c) the compressed component is treated thermally at a temperature of between 400.degree. and 3000.degree. C.