3D-Cf/SiC复合材料的弯曲强度及热膨胀性能分析

采用料浆浸渗和CVI工艺制备了含有ZrB₂陶瓷颗粒的3D-C_f/SiC复合材料，对其进行弯曲强度和线热膨胀系数测试，通过扫描电镜观察复合材料的表面及断口形貌。结果表明，3D-C_f/SiC复合材料的弯曲强度为107.99 MPa，满足一般热防护材料的使用要求；其线热膨胀系数随温度变化的规律是由于碳纤维和SiC陶瓷基体之间线热膨胀系数的不匹配及热残余应力造成的。

Bending and Thermal Expansion Properties of 3D-Cf/SiC Composites

3D-Cf/SiC composites with ZrB2 ceramic particle were prepared using chemical vapor infiltration (CVI) and slurry infiltration technology. The flexural strength and coefficient of thermal expansion (CTE) of the composites were analyzed. The surface and fracture morphology of the composites were studied using SEM. The results show that the 3D-Cf/SiC composites have a average flexural strength of 107.99 MPa, which meets the basic requirements of thermal protection materials; the regularity of the way in which the CTE of the composites vary with temperature is resulted from the mismatch of CTE between the fiber and matrix as well as the residual thermal stress in the composites.