添加有机氟化物的固体复合推进剂对EPDM绝热材料烧蚀特性研究

The high-aluminized (18%) solid composite propellants containing organic fluoride compound (OF) were prepared based on the three-component and four-component solid composite propellant formulations. The high-overload rocket motor for ablation simulation tests was employed to investigate the ablation effects of the above propellants on the Ethylene-Propylene-Diene Monomer (EPDM) insulation materials under the condition of the combustion chamber pressure of 7MPa. The results show that, in the cases that the substitution amount of OF is 3% in the formulations, the maximum linear ablation rate of the OF-containing propellants can be reduced by more than 30% comparing with the conventional blank formulations, and in the cases of four-component propellants, the OF-containing propellant can also effectively suppress the deposition of the condensed products in the rocket motor chamber. The study also discussed the ablation-reducing mechanism of propellants containing OF by investigating the burning surface characteristics of the propellants, analyzing the composition of the condensed depositions in the combustion chamber of the high-overload rocket motor, observing the surface carbon layer structures of the insulation materials after the experiments and characterizing the morphology of the surface deposition on the propellants' coating material. According to above analysis, the ablation-reducing mechanism of OF-containing propellants is attributed to the formation of smaller condensed combustion particles, which leads to their less momentum in the flow field, thereby suppresses the scouring effect on the insulation material and finally reduces the ablation properties.