Microstructure and ablation properties of the pierced C/C-SiC composites

Abstract:

The C/C-SiC composites were prepared by chemical vapor infiltration (CVI) combined with polymer infiltration carbonization (PIC) and reactive melt infiltration (RMI) using pierced non-woven carbon fiber felt preform. The microstructure and ablation properties were investigated. The results presented that non-woven carbon fiber cloth and pierced carbon fiber bundle formed dense C/C microstructure after CVI and PIC processes. SiC matrix was mainly located in the felt after RMI process and the content was 37.3wt%. SiC-rich layer was formed on the surface of the composites. When the ablation distance is 20mm, the ablation rates on XY and Z directions of the composites are 0.8×10_^-4 mm/s and 3.6×10_^-4 mm/s, respectively. The excellent ablation performance could be owing to the passive oxidation of SiC-rich layer on the surface. With the ablation distance decreased from 20mm to 10mm, the ablation rate of the composites changed slowly and then increased rapidly, because of the active oxidation ablation of the composites.