可陶瓷化EPDM绝热材料的烧蚀特性及陶瓷化机理  

Ablation characteristics and ceramization mechanism of ceramifiable EPDM insulation

作　　者：蔺自斌 王明超 汪远[2] 何永祝 常凯 任雯君[2] LIN Zibin;WANG Mingchao;WANG Yuan;HE Yongzhu;CHANG Kai;REN Wenjun(National Key Laboratory of Aerospace Chemical Power,Xiangyang 441003,China;Hubei Institute of Aerospace Chemotechnology,Xiangyang 441003,China;Wuhan University of Technology,Wuhan 430070,China)

机构地区：[1]航天化学能源全国重点实验室,襄阳441003 [2]湖北航天化学技术研究所,襄阳441003 [3]武汉理工大学材料科学与工程学院,武汉430070

出　　处：《固体火箭技术》2024年第3期388-396,共9页Journal of Solid Rocket Technology

摘　　要：绝热层中炭化层的特性与其耐烧蚀性能紧密相关。通过对可陶瓷化三元乙丙(EPDM)绝热材料氧乙炔烧蚀特性和成分进行表征分析,得到了线烧蚀率与炭化层不同参数之间的相关性,分析了类陶瓷炭化层的形成机理。结果表明,当可陶瓷化硅树脂填料含量在35~40 phr时,炭化层结构更致密,硬度更高,孔隙率更小,陶瓷产物更多,有效提高了EPDM绝热层的耐烧蚀性能;线烧蚀率与炭化层的结构与成分之间存在强相关性;类陶瓷炭化层结构的形成主要分为高分子聚合物的热分解、小分子物质的化学气相沉积、烧蚀表面SiC的原位生成和熔融SiO_(2)在炭化层中的填充粘结四个阶段,最终形成一种Si—O—C的复相陶瓷结构。The characteristics of carbonized layer in thermal insulation are closely related to its ablation resistance.Through characterization and analysis of structure and composition of carbonized layer of ceramicable EPDM insulation after oxygen-acetylene ablation,the correlation among different parameters of linear ablation rate of insulation layer and carbonized layer was obtained,and the formation mechanism of carbonized ceramic-like layer was analyzed.The results show that when the content of ceramifiable silicone resin filler is 35~40 phr,the carbonized layer possesses denser structure,higher hardness,smaller porosity and more ceramic products,which effectively improve the ablative resistance of EPDM insulation layer.There is a strong correlation between the linear ablation rate of the insulating layer and structure,composition of the carbonized layer.The formation of ceramic-like carbonized layer structure can be divided into four stages:thermal decomposition of polymer,chemical vapor deposition of small molecules,in-situ formation of SiC on ablated surface,filling and bonding of molten SiO_(2) in carbonized layer.Finally,a kind of Si—O—C composite ceramic structure is formed.

关 键 词：绝热层 EPDM 陶瓷化 炭化层 烧蚀特性 

分 类 号：V255[一般工业技术—材料科学与工程]