铝硅酸盐聚合物转化制备陶瓷材料具有耐热、耐腐蚀、可成型复杂形状构件、成本低、环境友好等优点，通过纤维强韧化可获得强度与韧性大幅度提高的陶瓷基复合材料，在航空航天、冶金、化工和国防等领域具有重要潜在应用。国内外在采用该技术制备纤维强韧陶瓷基复合材料及其高温损伤机制的研究仍很少。申请人前期工作表明，Cf/硅酸盐聚合物复合材料经适当高温处理后形成的Cf/榴石陶瓷基复合材料，表现出优异室温和高温力学性能，但高温长时间服役存在Cf氧化及界面反应导致性能恶化。若以SiCf代替Cf，不仅抗氧化性会大为改善，界面化学稳定性也可望迎刃而解。本申请拟研究复合材料在后续处理与服役环境下界面及基体的组织结构、力学性能及其断裂行为的演化规律，探讨其氧化动力学与抗氧化机理。该研究对进一步优化该复合材料体系，揭示其高温损伤机制，具有重要学术价值，也会为其在高温防热、高温构件等领域的工程应用提供理论指导与技术支持。

Ceramics derived from geopolymer possess many prominent properties of heat and corrossion resistance, forming complex-shaped components, low price and environmentally friendly nature, etc. Meanwhile, ceramics based composites with high strength and toughness can be obtained by the incorporation of fibers, which have wide potential applications in the area of aeronautics and astronautics, metallurgy, chemical engineering, and national defence, etc. However,there are only limited investigations on the ceramic based composites derived from geopolymer till now, and little work has been conducted on the high temperature failure mechanism of this kind of composites. Our preliminary investigations have proved that after proper heat treatment at certain high-temperature range, carbon fiber reinforced geopolymer composite can be directly converted into carbon fiber reinforced leucite composite, and room and high temperature mechanical properties can be enhanced greatly. However, once it is exposed to an elevated temperature for longer duration or at a higher temperature such as above 1200℃, the Cf/Leucite composites suffer from the problems of fiber oxidation and interface reaction, which are detrimental to the performance of the composites. In this project, SiC fiber will be adopted to substitute the carbon fiber, in order to improve the interface compatibility between fiber and leucite matrix and to enhance the high-temperature oxidation resistance of the composites. Microstructure, mechanical properties and fracture mechanism will be investigated during the post-heat treatment and sevice temperature. The oxidation kinetics and anti-oxidant mechanism of the composites will be systematically investigated. The research can achieve optimized property design of the SiC fiber reinforced leucite composites and reveal the high-temperature damage mechanisms of this kind of composite. Meanwhile, the relevant results will provide theoretical and technical supports for the optimization of SiCf/leucite composites and their engineering applications targeted for high-temperature heat-resistant components and will reveal their failure mechanisms at elevated temperature.