Study on the Densification Efficiency of Pitch-Based C/C Composites

C/C composites were prepared by using high temperature coal tar pitch as impregnant and preform woven by axial carbon rods as reinforcements via the process of impregment /carbonization.The densification efficiency of composite was studied at different procedure.The microstructure was observed by scanning electron microscope.The results show that with increase of cycle number,density of composites increased,the increment of density decreased gradually.Intermediate graphitization treatment appreciably reduces the density of composites,but the ultimate densities of composites are also more than 1.90g/cm3.Microscopically,a little cracks and holes still exist within composites,pitch coke are mainly of domain,flow domain and mosaics domain.