Ablative behavior and mechanical properties of C/C-SiC composite materials for combustion chamber of liquid ramjet engines

Abstract

The C/C-SiC composite materials combustion chamber layer was tested with liquid ramjet engines with solid particles or without solid particles separately at different oxygen contents. The ablation amount， ablative behavior and mechanical properties of the material after ablation in critical and general areas were studied under two test conditions. The results show that under the condition of containing solid particles， the amount of ablation in the critical ablation area is large， and the amount of ablation in the general area is also large， which is larger than that of the corresponding areas without solid particles. The surface coating of C/C-SiC composites undergoes oxidation reaction first， and the resulting SiO2 glassy film covers the surface of the coating， blocking the entry of oxygen and effectively protecting the matrix material. As the temperature rises， active oxidation of the material occurs， and the process is accelerated by air erosion and scouring， making it difficult for SiO2 to adhere to the inner surface of the product， and the SiC matrix and carbon fiber are lost without protection. The fibers become thinner， the strength decreases gradually， and the toughening effect of the fibers is reduced greatly， so the bending strength and shear strength of the C/C-SiC composites decrease under two test conditions， and the mechanical property loss of the material is more serious under particles scouring.

Keywords

• c/c-sic combustion chamber
• liquid ramjet
• solid particle
• ablative behavior
• mechanical property