采用透射电镜研究了SiCf/Super α2复合材料的界面反应及其对抗拉强度的影响。结果表明,制备状态的复合材料的界面反应产物为4层分布,经高温长时间热处理后,界面反应区可分为6层,电子衍射分析和成分分析表明:界面反应产物为TiC,Ti3AlC,Ti3Si和Ti5Si3。界面反应层的加厚服从抛物线规律,是一个扩散控制过程。复合材料的抗拉强度随界面反应层的加厚而下降,计算表明:SCS-6 SiCf/Super α2复合材料的抗拉强度不受影响的临界界面反应区厚度为0.75μm。
The interracial reaction and its effects on the tensile strength of the SCS-6 SiC/Super α2 composites was studied by means of transmission electron microscopy. It is shown that interracial reaction products distribute in four layers in the as-processed composite but in six layers in the composites after heat treatment at high temperature for a long time. By the way of electron diffraction and composition analysis, the interracial reaction products were identified as TiC, Ti3AlC, Ti3Si and Ti5Si3. It is shown that the thickening of the interracial reaction zone is diffusion controlled and obeys a parabolic law with reaction time. It is found that the tensile strength of the SCS-6 SiC/Super α2 composites decreases with the thickening of the interracial reaction zone. The minimum thickness was determined as 0.75 μm that has no influence on the tensile strength of the SCS-6 SiC/Super α2 composites.