采用电泳沉积(EPD)在1k 碳布表面均匀加载了碳纳米管(CNTs),借助化学气相沉积(CVD)致密化碳布叠层预制体,制备了EPD CNTs掺杂的二维(2D)碳/碳(C/C)复合材料。研究了EPD CNTs对2D C/C复合材料致密化过程、微观组织和弯曲性能的影响。研究结果表明：EPD CNTs在碳纤维表面呈现平面内高密度、杂乱取向分布特征,该形貌CNTs降低了热解炭在碳纤维预制体内的沉积速率,诱导了高石墨微晶堆垛高度(Lc)、低(002)晶面面内方向上的沉积有序度(La)热解炭的形成； EPD CNTs 的掺杂可提高 C/C 复合材料的弯曲强度和模量：当 CNTs 含量为0.74wt%时,复合材料弯曲强度和模量可达150.83 MPa和23.44 GPa,比纯C/C复合材料提高了31.4%和13.9%；继续提高 CNTs 含量,复合材料弯曲强度降低,这与过高含量 EPD CNTs 导致复合材料密度降低有关；同时, EPD CNTs 的掺杂使得 C/C 复合材料断裂模式由脆性断裂转变为假塑性断裂,复合材料断裂塑性的提高是由于 EPD CNTs造成的碳基体结构的变化以及碳纤维的大量拔出。
Carbon nanotubes (CNTs) were deposited uniformly on 1 k carbon cloth by electrophoretic deposi-tion (EPD). After that, CNT-doped clothes were stacked and densified by pyrocarbon via chemical vapor de-positon (CVD) to prepare two dimensional (2D) carbon/carbon (C/C) composites. Effects of EPD CNTs on CVD process, microstructure and flexural property of 2D C/C composites were investigated. Results show that EPD CNTs are dispersed in the plane parallel to carbon fiber surface with random orientations and a high dis-tribution density, leading to the decrease of densification rate of EPD CNT-doped C/C composites and the formation of pyrocarbon with high Lc and small La values. EPD CNTs increase the flexural strength and modulus of C/C composites and the improvements can reach 31.4%and 13.9%when the loading of EPD CNTs is 0.74wt%, with corresponding flexural strength and modulus being 150.83 MPa and 23.44 GPa, respectively. Further increasing the dope of EPD CNTs can decrease the flexural property of C/C composites, resulting in their bulk density decrease. The introduction of EPD CNTs changes the fracture mode of C/C composites from brittle fracture to pesudo-plastic fracture, which is related to the change of pyrocarbon in microstructures and the resulted carbon fiber pullout.
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