Abstract: In order to enhance densification efficiency and decrease the costs of preparation, a novel isothermal chemical vapor infiltration process for fabrication C/C composites was developed by decreasing the space of around preforms in the conventional hot wall reactor. With volume fraction of 28.7%, and infiltrated by the novel ICVI at ambient pressure and 1100℃, residence time of 0.1s, and methane as precursor, nitrogen as diluted gas, the 2D fiber felt preform was densified. The texture of the obtained sample was investigated by using a polarized light microscope and the flexural stength was determined by three-point bonding tests, after the tests, the morphology of the fracture surface was observed by using SEM. The resuts show that the bulk density of the C/C composite prepared in 125h is 1.73g/cm³, and the density distribution is uniform. Its texture is pure rough laminar. Its flexural strength is 250.87MPa. Its flexural modulux is 29.29GPa. The C/C composite exhibits a pseudo-plastic failure behavior.

Key words: C/C composites, chemical vapor infiltration, residence time, rapid densification