Al₂O_3f/SiO₂ composites were fabricated efficiently using sol‐gel process. The degradation behavior exposed to Na₂SO₄ environment at 1100℃ and MMH/N₂O₄ bipropellants test were investigated and compared. The results showed that the strength of Al₂O_3f/SiO₂ composites gradually decreased as the ratio of Na₂SO₄:water increased; the strength of the composites was only 23.56 MPa at 20% (Na₂SO₄:water), which suggested that the composites maintained lower strength. Cracks began to appear in SiO₂ matrix, and the structure of Al₂O₃f/SiO₂ composites could be corroded which would corrode the SiO₂ matrix, leaving naked fibers. Developing a protective layer with higher stability for Al₂O_3f/SiO₂ composites would be considered for long time use. The composites showed higher ablation resistance to MMH/N₂O₄ bipropellant test; the flexural strength was (77.15 ± 4.56) MPa and the retention ratio was 98.7%. The degradation of Al₂O_3f/SiO₂ composites was promoted owing to the thermal‐mechanical and chemical factors. SiO₂ matrix became weak and fragile at elevated temperature; some SiO₂ matrix became loosened and porous after being washed away through the shearing of MMH/N₂O₄ bipropellants, which prevented cracks from penetrating Al₂O₃ fibers. With ongoing test, the fibers were worsened by thermal‐mechanical corrosion.

中文翻译：

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暴露于Na2SO4环境中的Al2O3f / SiO2复合材料的降解和MMH / N2O4双推进剂测试

Al ₂ O _3f / SiO ₂复合材料通过溶胶-凝胶工艺有效地制备。研究并比较了1100℃ Na ₂ SO ₄环境下的降解行为和MMH / N ₂ O ₄双推进剂试验。结果表明，随着Na ₂ SO _4与水的比例增加，Al ₂ O _3f / SiO ₂复合材料的强度逐渐降低。在20％（Na ₂ SO _4时，复合材料的强度仅为23.56 MPa：水），这表明复合材料保持较低的强度。SiO ₂基体中开始出现裂纹，Al ₂ O ₃ f / SiO ₂复合材料的结构可能被腐蚀，从而腐蚀SiO ₂基体，留下裸露的纤维。对于长时间使用Al ₂ O _3f / SiO ₂复合材料，要开发出具有更高稳定性的保护层。复合材料对MMH / N ₂ O ₄双推进剂试验显示出更高的耐烧蚀性；弯曲强度为（77.15±4.56）MPa，保持率为98.7％。Al ₂ O _3f的降解由于热力学和化学因素，/ SiO ₂复合材料得到了推广。SiO ₂基体在高温下变得脆弱易碎。由于MMH / N ₂ O ₄双推进剂的剪切作用，一些SiO ₂基体被冲刷掉后变得疏松多孔，防止了裂纹穿透Al ₂ O ₃纤维。经过不断的测试，纤维由于热机械腐蚀而变质。