Chemical vapor infiltration of C/C composites: Fast densification processes and matrix characterizations Original Research Article

Fast densification processes have been developed to improve the fabrication of C/C composite materials. In this work, a comparison is made between two techniques: the film boiling technique with a liquid reagent and the gas infiltration method. In both methods, the same home-made reactor was used. For the film boiling technique, the preform is either wrapped or not with a porous thermal barrier. Two different substrates have been densified, a carbon felt (RVC-2000® from Le Carbone-Lorraine), and a 3D carbon cloth (Novoltex® from Snecma). In situ temperature gradients and their temporal changes during the infiltration process have been recorded together with the delivered power necessary to maintain a constant deposition temperature. From these experiments, we have concluded about the following main points: • the analysis of in situ parameters, powers and temperatures, and the associated profiles of the pyrocarbon deposits, • the matrix quality with their associated microstructures as characterized by helium density, optical microscopy and Raman scattering experiments, • the key role of the evolutive preforms as heat and mass exchangers during the process, and the assisted thermal fluxes inside the reactor. This paper presents results which should allow to control automatically the process at an industrial scale.