Flexible ablative materials play a key role in thermal protection systems to protect space vehicles during hypersonic flight missions. In this work, epoxy resin modified liquid silicone rubber was adopted as elastomeric matrix. Two inorganic fibers (carbon fibers (CF) and quartz fibers (QF)) and two organic fibers (aramid fibers (AF) and poly (p‐phenylene benzobisoxazole) fibers (PBO)) were chosen as functional fillers. The ablation resistance and thermal insulation properties were evaluated using oxyacetylene torch test. Microstructure and phase composition of the char layer was fully characterized to investigate the ablation mechanism. SEM observations revealed that the fibers are well dispersed and integrated in the matrix. TGA analysis indicated that the inorganic fibers possess significantly higher thermal stability than organic fibers. In addition, a molten silica film can be formed on the material surface, which can exert a better thermal protection effect on the matrix. Furthermore, the ablation test shows that the linear ablation rate decreases first and then increases with an increase of fiber content. This work provides basic data to guide optimal selection of fibrous ablatives to enhance ablation performance.

中文翻译：

---

填充不同纤维的液态硅橡胶复合材料的耐烧蚀性能比较

柔性烧蚀材料在热保护系统中起着重要作用，可在高超声速飞行任务中保护航天器。在这项工作中，采用环氧树脂改性的液态硅橡胶作为弹性体基质。选择了两种无机纤维（碳纤维（CF）和石英纤维（QF））和两种有机纤维（芳纶纤维（AF）和聚（对苯撑苯并二恶唑）纤维（PBO））作为功能性填料。使用氧乙炔焊炬试验评估耐烧蚀性和绝热性能。充分表征了炭层的微观结构和相组成，以研究烧蚀机理。SEM观察表明，纤维良好地分散并整合在基质中。TGA分析表明，无机纤维具有比有机纤维明显更高的热稳定性。另外，可以在材料表面上形成熔融的二氧化硅膜，这可以对基质发挥更好的热保护效果。此外，烧蚀测试表明，线性烧蚀率随着纤维含量的增加先降低然后增加。这项工作提供了基础数据，以指导纤维消融剂的最佳选择，以增强消融性能。