Ablation characteristics of C/C composites in reentry simulation conditions

In order to study the ablation characteristics of axial carbon rod C/C composites, the ablation experiments were conducted by reentry simulation condition ablation system based on thermal plasma. The nitrogen(N2), oxygen(O2) and air were taken as the operation gases, and the ablation characteristics and ablation rates of the specimens in different conditions were compared. The results show that the micro-morphologies and the ablation rates are different in three operation gases conditions. The linear and mass ablation rates are listed as follows: oxidation of O2(0.0423mm/s and 0.0451g/s)> nitridation of N2(0.0314mm/s and 0.0338g/s)> composite reactions of air (0.0215mm/s and 0.0208g/s). There are some tiny cracks in thermal influencing areas, and the ablation mechanisms of the C/C composites in three operation gases conditions are differents. They are some combinations of sublimation of carbon, carbon oxide and carbon nitrogen reaction.