中文摘要：

为了确定薄界面3D C/SiC复合材料,即热解炭界面（PyC界面）厚度低于标准厚度（200 nm）的复合材料,在应力下和氧化性气氛中的抗热震性,利用感应加热环境箱在700～1200℃氧化性气氛中进行了热震试验,基于试验后的强度保持率变化、拉伸应力-位移曲线变化、微结构变化和试验过程中的长度变化等研究了气氛和应力对其热震损伤行为的影响。研究发现,对于薄界面3D C/SiC复合材料,应力增加了裂纹开度,促进了C相的氧化,加快了热震损伤饱和速度,且蠕变应力对热震损伤的加速作用高于疲劳应力。氧化性气氛对界面的适度氧化和应力导致的界面脱粘能提高了薄界面3D C/SiC复合材料的强度保持率,说明其在应力条件下具有较好的抗氧化和抗热震性能。

英文摘要：

To investigate the thermal shock resistance of 3D C/SiC composites with a thin interlayer under stresses and oxidizing atmospheres whose thickness of the interlayer is thinner than the standard one（200 nm）,the thermal shock tests were carried out in the temperature range between 700 and 1200℃ in oxidizing atmospheres under fatigue or creep stresses.Effects of stress and atmosphere on the degradation behaviors of the 3D C/SiC composite were investigated by the residual tensile strength,the stress-displacement curves,the length change curves and the morphologies.It is found that the oxidation of carbon and the degradation saturation of the composite under thermal shock are accelerated by the stress because of the cracks widen.The effect of creep stress on the degradation of the composite is greater than that of the fatigue stress.The residual tensile strength of the composite is enhanced by a limited oxidation and debonding of the interlayer resulted from the oxidizing atmosphere and the stress.It is shown that the thermal shock resistance of the composite with a thin interlayer is good even under the stress