Patent ID: 8894918

Claim:
A method for treating ceramic fibers comprising: providing textile-formed ceramic fibers having internal stresses therein; providing a mandrel having a desired net shape; creating a preform by applying reshaping stresses to the fibers onto the mandrel so that the preform takes the desired net shape of the mandrel; placing the preform and mandrel into a processing furnace for thermal treatment at a processing temperature for a processing time and in a processing gas at a pressure at or between 0.1 MPa (1 atm) and 4.0 MPa (40 atm); relaxing by fiber creep during thermal treatment the internal stresses created in the fibers by the textile forming and by the perform shaping; maintaining during thermal treatment high fiber strength while simultaneously improving fiber creep resistance; and creating, as a result of the thermal treatment, a stress-free preform with the near-net shape of the mandrel.