Patent ID: 7105111

Claim:
A process for the production of ceramic composite materials which are reinforced with carbon fibres and have recesses and hollow spaces, where cores whose shape corresponds to that of the hollow spaces are produced in a first step, a green body is produced in a second step by introducing the abovementioned cores and a press moulding compound into a mould, where the press moulding compound comprises carbon fibres and/or carbon threads and pitch and/or resins which form carbon-containing residues on heat treatment in the absence of oxidants, in such a way that the position of the cores corresponds to the desired position of the hollow spaces to be formed, the green body is cured by heating to a temperature of from 120° C. to 280° C. under pressure in a third step, the cured green body, also referred to as intermediate body, is carbonised in a fourth step by heating in the absence of air and other oxidants to a temperature of from about 750° C. to about 1100° C. to give a C/C body. wherein the cores are made of a material which has a heat distortion temperature of at least 200° C. and is non-meltable but undergoes at least a shrinkage of 10% of the original core volume above the curing temperature of the press moulding compound sufficient for the shrunken core to be able to be taken out from the carbonised body, and wherein the press moulding compound of the second step comprises carbon fibres in the form of coated short fibre bundles as reinforcing material.