两种双基体C/C复合材料的微观结构与力学性能

Microstructure and Mechanical Properties of Two Kinds of Dual-matrix C/C Composites

借助偏光显微镜、扫描电镜以及力学性能测试研究了两种双基体C/C复合材料的微观结构与力学性能。结果表明:基体碳在偏光显微镜下呈现出热解碳的光滑层组织,沥青碳的各向同性、镶嵌和流域组织。在SEM下普通沥青碳为"葡萄状"结构,中间相沥青碳为片层条带状结构。具有多层次界面结构的材料可以提高材料的弯曲强度,改善材料的断裂韧度,两种材料在载荷-位移曲线中载荷为台阶式下降,呈现出假塑性断裂特征。材料A和材料B的弯曲强度分别为206.68,243.66MPa,断裂韧度分别为8.06,9.66MPa·m1/2,材料B的弯曲强度、断裂韧度均优于材料A。

The microstructure and mechanical properties of two kinds of dual-matrix C/C composites were studied by polarized light microscopy （PLM） , scanning electron microscopy （SEM） and mechan-ical properties tests techniques respectively. PLM results indicate that the matrix carbon exhibits the smooth laminar structure of the pyrocarbon, the isotropic, mosaics and flow domains of the pitch car-bon. The TEM results show the normal pitch carbon is the grape structure; the mesophase pitch car-bon is the lamellar banded structure. Materials with multi-interface structure can improve the flexural strength and fracture toughness, the load-displacement curve shows the load drop is decreased for step type, the composites show a pseudo-plastic fracture characteristics. The flexural strengths of the ma-terial A and material B are 206. 68MPa and 243. 66MPa, the fracture toughness are 8. 06MPa · m1/z and 9. 66MPa · m1/z , respectively. The flexural strength and fracture toughness of material B are both superior than that of material A.