过载条件下不同配方体系绝热材料筛选及烧蚀特性

Insulator material screen experiments and ablation characteristicunder high acceleration condition

关键词:  固体推进剂火箭发动机  绝热层  烧蚀  实验研究

Key words:  Solid propellant rocket motor (SRM)  Insulator  Ablation  Experimental investigation

摘要:

以国内某发动机在飞行过载下绝热层的异常烧蚀为研究背景,基于地面过载模拟装置,模拟了飞行过载条件下的颗粒冲刷状态参数,针对不同配方体系的绝热材料开展了筛选试验以及烧蚀特性研究,实验获得了三种材料的最大炭化烧蚀率和质量烧蚀率,筛选出了实验条件下抗颗粒冲刷能力较强的绝热材料,并针对实验后绝热材料的炭化层进行了电镜扫描分析,结合绝热材料配方开展了抗烧蚀特性分析。研究结果表明:(1)在实验条件下,材料B的炭化烧蚀率和质量烧蚀率均最大,材料A的居中,材料A1的最小,材料A1的抗颗粒冲刷性能最佳；(2)由于芳纶纤维的原位成炭特性,决定了三元乙丙/芳纶纤维体系绝热材料的炭化层具有一定结构强度,而恰当的纤维和SiO₂含量将会增强绝热材料的抗烧蚀性能；(3)根据研究结果,建议在工艺允许的情况下,可以考虑研制同时采用芳纶纤维和石棉纤维的绝热材料体系,在针对颗粒冲刷条件时,炭化层内即有可以形成骨架结构的芳纶纤维,又可以利用石棉纤维在受热分解时SiO₂和MgO熔融后和纤维以及基体之间的粘结交联效应。

Abstract:

Focusing on the abnormal ablation of certain model solid rocket motor under flight overload condition, insulator material screen experiments were carried out based on the experimental simulation facility of high acceleration condition. Through the screen experiments the maximal carburization ablation rate and mass ablation rate were obtained, and the sort order of three kind of insulator ablation characteristic was achieved. In order to analyze the ablation mechanism of insulator, the surface and cross section configuration of the carburization layer were obtained by using the scanning electron microscope. The results show that:(1) under the same particles impacting conditions, the carburization ablation rate and mass ablation rate of insulator material B is maximal and A1 is minimal than others, and the material A take second place. The anti-particle erosion ability of material A1 is best than others. (2) the appropriate quantity of fiber and SiO2 could intensify the erosion resistance of ablatives because of the formation of the framework structures on carburization layer through the carbonization in situ of aramid fiber; (3) the new type insulator material system reinforced by aramid fiber and asbestos fiber synchronously was proposed.