中间相沥青基炭/炭复合材料的微观结构与力学性能(英文)

Microstructure and Mechanical Properties of Mesophase Pitch-Based C/C Composites

借助偏光显微镜、扫描电镜、透射电镜以及力学性能测试研究了微观结构对中间相沥青基炭/炭复合材料力学性能的影响。结果表明:基体炭在偏光显微镜下呈现出光学各向异性,在SEM和TEM下呈片层条带状结构。基体炭与纤维之间的界面不连续,为"裂纹型"界面。材料受载破坏时裂纹通过改变扩展路径而延缓其扩展速度,在纤维一基体界面处以及基体炭层片之间引起滑移,在断口形貌上体现出断裂台阶适中且与纤维拔出交替进行,表现出韧性破坏的断裂特征,材料具有较高的力学性能,抗弯强度达到257MPa.

Microstructures and mechanical properties of 2D PAN fiber-reinforced mesophase pitch-based C/C composites were studied by polarized light microscopy （PLM）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM） and mechanical testing experiments. The results show that the matrix carbon exhibits optical anisotropy under PLM. The mesophase pitch carbon exhibits lamellar structure and its orientation is roughly parallel to the carbon fiber axis. Besides, the micro-cracks inside the matrix and those at the fiber-matrix interface are also parallel to the carbon fiber axis. The non-brittle fracture behavior of the composites is related to multiple crack deflections caused by the interface and micro-cracks within the matrix carbon. The flexural strength of composites is up to 257 MPa.