为了研究三元乙丙基础配方、抗过载配方、无SiO2配方和无纤维配方等不同配方绝热材料在颗粒冲刷条件下的烧蚀特性和机理,基于高过载地面模拟试验发动机,开展了烧蚀试验研究。分析了实验后绝热材料的表面以及断面形貌特征和宏观烧蚀率结果,探讨了三元乙丙基础配方和抗过载配方绝热材料炭化层中致密结构形成的机理,进行了不同配方材料的烧蚀模式和机理的分析。研究结果表明:相同颗粒冲刷条件下,不同配方三元乙丙材料烧蚀模式和破坏机理不同,烧蚀率从小到大依次为抗过载配方<基础配方<无SiO2配方<无纤维配方;其中基础配方和抗过载配方三元乙丙材料在烧蚀过程中炭化层形成"致密/疏松"结构,表面形成的致密结构可以提高材料的抗烧蚀性能,无SiO2和无纤维三元乙丙材料以基体的粒状和块状剥落破坏为主;不同配方绝热层炭化层的形貌和结构与纤维、SiO2含量以及烧蚀环境密切相关。

Ablation experiments of particle erosion for EPDM basic formulation,overload resistance formulation,no SiO2 formulation and no fiber formulation were performed on ground simulation test motor with high overload.Based on the results of ablation rate and surface characteristic of carburization layer,the formation mechanism of compact structure in carburization layer with both basic formulation and overload resistance formulation was studied.Ablation modes for variety formulation materials were analyzed as well.The results show that:the ablation ratios of different formulation at the same particles impacting conditions rank as follows:overload resistance formulation<basic formulation<no SiO2 formulation<no fiber formulation.It also shows that there are huge discrepancies in the surface and fracture surface profiles of insulation layer,erosion modes and destroy mechanisms of different formulations.Compact and loose structures were formed in carburization layer of both basic formulation and overload resistance formulation during erosion process.While no SiO2 formulation and no fiber formulation materials are destroyed mainly by graininess and sheet shape remove.Finally it shows that the erosion resistance of ablatives is improved by the compact structures on the surface,which are close related to the content of the fiber,SiO2 and the erosion environment.

V435.14

国家自然科学基金(50376073)