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 mechanical 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 carbon.The TEM results show the normal pitch carbon is the grape structure;the mesophase pitch carbon 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 material A and material B are 206.68MPa and 243.66MPa,the fracture toughness are 8.06MPa · m1/2 and 9.66MPa · m1/2,respectively.The flexural strength and fracture toughness of material B are both superior than that of material A.%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.
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