为研究固体火箭发动机包覆层材料在不同热解程度下的微观结构和力学行为,通过热重分析得到三元乙丙(EPDM)包覆层的热解温度范围。分别对不同热解温度下的EPDM试件进行力学实验和电镜扫描,并从微观角度分析材料力学行为发生变化的原因。结果表明:在初始热解程度下,材料只是发生了少量的失水和气体的逃逸,其力学行为仍属于粘超弹材料范畴;随着材料热解程度的增加,部分材料基体发生裂解,其力学行为表现为脆性材料特性。

In order to study microstructure and mechanical behavior of inhibitors in solid rocket motor at different pyrolysis temperature, Thermogravimetric analysis was conducted at EPDM to obtain its range of pyrolysis temperature, followed by mechanical tests and scanning electron microscopic analysis conducted at EPDM specimens taken at different pyrolysis temperature, thus the reason of the material mechanical behavior transformation was found from a view at microcosmic level. The results show that only slight dehydration and gas fugitive are observed when pyrolysis progress initiates, in the meantime, the material still possess the viscoelastic mechanical properties. While the pyrolysis being exacerbated, segments of the material matrix are dissociated, thus the mechanical behavior of EPDM turns to be brittleness.