压力梯度CVI工艺制备2D炭/炭复合材料的弯曲断裂行为

采用三点弯曲方法测试了压力梯度化学气相浸渗法(CVI)工艺制备的2D炭／炭复合材料的性能，借助于扫描电镜研究了断口和界面形貌，分析了密度和纤维基体界面对材料力学性能的影响。结果表明，随试样密度增加，2D炭／炭复合材料的断裂模式从剪切断裂、层问分离向拉伸断裂转变。材料密度对弯曲强度和模量影响很大，但对弯曲挠度基本没有影响。揭示了影响2D炭／炭复合材料弯曲挠度的关键因素是纤维与热解炭基体界面的结合情况。

Flexural behavior of 2D carbon-carbon composites fabricated by pressure gradient CVI

The flexural behavior of 2D carbon-carbon (C/C) composites fabricated by CVI was investigated using a three-point bend test, and the fracture surface and interface of the composites were observed by SEM. By analyzing the effects of the fiber-matrix interface and the sample density on the mechanical behavior, it is revealed that the fracture modes of 2D C/C ~composites) change from shearing and delamination failure to tensile breakage with increasing densification degree. The results also show that the density has a great impact on the strength and modulus rather than the flexural deflection. In fact, the flexural deflection of 2D C/C composites depends on the performance of the pyrocarbon and the interfacial bonding between fibers and matrix.