【摘要】 C/C复合材料是一种高性能新型复合材料，但是脆性大、韧性差的缺点限制了其广泛应用。因此，本研究利用化学气相渗透(CVI)法，设计并制备了三种C/C复合材料，基体炭分别为粗糙层、光滑层以及粗糙层/各向同性层带状结构热解炭，研究了C/C复合材料的微观结构、沉积机理、断裂行为和增韧机制。结果表明，三种C/C复合材料的抗弯强度分别为189.1、191.5、233.5 MPa。粗糙层和带状结构炭基体的C/C复合材料为假塑性断裂，而光滑层炭基体的C/C复合材料则是明显的脆性断裂。与粗糙层炭基体的C/C复合材料相比，带状结构炭基体的C/C复合材料通过不同结构热解炭之间的界面滑动，使得应变量增加了约70%,韧性得到了提升。因此，通过控制CVI工艺参数，实现带状结构热解炭制备，可以有效优化C/C复合材料的韧性。更多还原

【Abstract】 C/C composites are a new type of high-performance composites, but their shortcomings of high brittleness and poor toughness limit their wide application. Therefore, in this study, three kinds of C/C composites were designed and prepared using the chemical vapor infiltration(CVI) method with matrix carbon: rough layer, smooth layer, and rough layer/isotropic layer band-structured pyrolytic carbon(PyC), respectively. And the microstructures, fracture behaviors, and toughening mechanisms of C/C composites were investigated. The results indicate that the flexural strength of the three C/C composites is 189.1, 191.5, and 233.5 MPa, respectively. The C/C composites with rough layer and band-structured carbon matrix are pseudoplastic fractures. In contrast, the C/C composites with smooth layer carbon matrix are brittle fractures. Compared to the C/C composites with rough layer carbon matrix, the C/C composites with band-structured carbon matrix show a significant increase in toughness through interfacial sliding between the different structured pyrolytic carbon, which increases strain amount by about 70%. Therefore, the toughness of C/C composites can be effectively optimized by controlling the parameters of the CVI process to achieve band-structured pyrolytic carbon preparation.更多还原