Abstract: Using polyacrylonitrile (PAN) based carbon fiber weft free cloth and short-cut mesh fiber interactive laminated acupunture, the BaTiO₃ with different mass fractions (0%, 5%, 15%, 25% and 35%) was introduced in the preparation process to prepare the longitudinal fiber arranged ring carbon fiber preforms. The method of chemical vapor deposition (CVD) and liquid phase impregnation was combined. BaTiO₃ modified carbon/carbon composites were prepared. The mechanical properties of the composite were tested in both vertical and parallel directions, and the microstructure and morphological characteristics of the fracture were observed. The results show that the introduction of nano-BaTiO₃ accelerates the nucleation and growth of pyrolytic carbon, and changes the structure of pyrolytic carbon, the single smooth layer is transformed into smooth layer and rough layer. With the increase of BaTiO₃ content, the vertical compressive strength of the composite is basically unchanged first and then gradually increases, while the parallel compressive strength first increases and then decreases. The fracture mode of the composite under vertical compression is brittle fracture, and the fracture mode under parallel compression is brittle fracture with the characteristics of interlaminar fracture.

Key words: C/C composite, BaTiO₃, vertical compression, parallel compression, brittle fracture, interlaminar fracture