Densification of a 2D carbon fiber preform by isothermal, isobaric CVI: Kinetics and carbon microstructure

Chemical vapor infiltration of a 2D carbon fiber preform with a 0/0/90/90° fiber architecture and a fiber volume fraction of 22.5% was investigated as a function of methane pressure at various temperatures as well as a function of infiltration time at constant pressure. Inside–outside densification was obtained at the most attractive temperature of 1095 °C up to 29 kPa resulting in a maximum bulk density of 1.84 g cm −3 and a matrix density of 2.17 g cm −3, which corresponds to high-textured carbon. Texture formation can be perfectly explained with the earlier proposed particle-filler model. Studies at increasing infiltration times suggest a recrystallization of carbon deposited in the early stages of the infiltration.