晶须增韧补强超高温陶瓷基复合材料因其优异的力学性能及抗氧化性能，在高温热防护材料研究领域显示出巨大的应用潜力。高温下，其强韧性能与室温下有很大差异，且往往伴随氧化导致的强韧性能急剧退化等问题。鉴于已有研究还难以满足对其高温强韧性能获取、预测及表征等重大需求的现状，本项目拟采用宏细观相结合、试验与理论相结合的手段，对其系统地开展高温强韧性能影响机理及表征方法研究，建立考虑宏微观结构因素影响的高温强韧性能理论表征模型与计及表面氧化损伤影响的高温断裂强度理论表征模型，为其在高温下的失效分析与强韧性能的表征及预测提供有力的技术手段。利用所建立的理论表征模型开展影响因素分析，基于微结构分析与控制、多相复合强韧化及协同增强增韧的思路，提出提高晶须增韧补强超高温陶瓷基复合材料高温强韧性能的有效方法和途径。本项目的研究成果可为晶须增韧补强超高温陶瓷基复合材料的强韧化设计与高温应用提供理论基础和技术储备。

Whisker toughened and reinforced ultra-high temperature ceramic matrix composites have great potential applications in the field of high-temperature thermal protection material research due to their excellent mechanical properties and antioxidant properties. Their obdurabilities at elevated temperatures are quite different from those at room temperature, and are often accompanied by the rapid degradation caused by oxidation. Existing researches are difficult to meet the major demand for the acquisition, prediction and characterization of their high-temperature obdurabilities. Therefore, this project will systematically investigate the influence mechanisms and characterization methods of their high-temperature obdurabilities using experiment and theory from both macro and micro perspectives. Theoretical characterization models of their high-temperature obdurabilities, which can take the macro and micro structural factors into account, will be given. High-temperature fracture strength model, considering the effect of surface oxidation damage, will be established. Powerful technical means for their failure analysis and the characterization and prediction of their obdurabilities under high temperature environment will be provided. In addition, systematical influencing factor analysis will be conducted using these models. Based on the analysis and control of microstructure, and the strengthening-toughening mechanisms of multi phase and synergistic effect, some effective methods to improve their high-temperature obdurabilities will be proposed. The research results of this project can provide theoretical basis and technical reserve for the strengthening-toughening design and the high temperature application of whisker toughened and reinforced ultra-high temperature ceramic matrix composites.