中文摘要：

结合复合材料氧化质量损失率模型和混合率公式，发展了单向c／sic复合材料在无应力氧化下的弹性模量预测方法。对400～700℃和700～900℃两种氧化机制下C／SiC复合材料的弹性模量进行了预测，分析了氧化温度、氧化时间和纤维体积含量对C／SiC复合材料弹性模量的影响。开展了单向C／SiC复合材料在650℃和800℃空气环境下的无应力氧化试验，建立了复合材料质量损失率与氧化时间的变化关系，得到了氧化后材料拉伸应力-应变曲线。同时，将理论预测值与试验结果进行对比，发现理论值与试验值基本吻合，从而验证了该方法能够有效地预测无应力氧化下陶瓷基复合材料的弹性性能。

英文摘要：

An approach to predict the elastic modulus of unidirectional C/SiC composites at 400~900 ℃ oxidation environments was developed. The approach combined the mass loss rate model with the mixed rule formulation. The elastic modulus of C/SiC composites at 400~700 ℃ and 700~900 ℃ air environment which represents two different kinds of oxidation model was predicted. The influence of oxidation temperature, oxidation time and fiber volume fraction on composites elastic modulus was analyzed. The experiments of C/SiC composites at 650 ℃ and 800 ℃ air environment with non-stress have been performed, the relationship between mass loss rate and oxidation time has been established, and the tensile stress - strain curves have been obtained. Besides, the theoretical results have been compared with the experimental data. It is found that the predicted results agree well with the experimental ones. And it is verified that the approach developed in this paper can predict the elastic modulus of ceramic matrix composites under non stress oxidation efficiently.