Carbon-bonded carbon fiber (CBCF) composites are novel and important high-temperature insulation materials owing to their light weight, low thermal conductivity and high fracture tolerance. To further improve the mechanical property of CBCF composite, we propose a three-dimensional (3D) SiC nanowires structure, which is in situ grown on a CBCF matrix via directly annealing silicon oxycarbide (SiOC) ceramic precursor. The synthesized multiscale reinforcements including microscale SiOC ceramics and nanoscale SiC nanowires are mainly attributed to the initial phase separation of SiOC phase and subsequent solid-phase reaction of SiO and C phases. Compared to SiOC/CBCF composite, the resulting 3D SiC nanowires/SiOC/CBCF hybrid structure exhibited high flexural/tensile strength and fractured strain due to the pull-out and bridging behavior of SiC nanowires. This one-step process supplied a feasible way to synthesize 3D SiC nanowires to reinforce and toughen SiOC-modified CBCF composite.

碳键碳纤维（CBCF）复合材料由于其重量轻，导热系数低和耐断裂性高而成为新型且重要的高温绝缘材料。为了进一步改善CBCF复合材料的机械性能，我们提出了一种三维（3D）SiC纳米线结构，该结构通过直接退火碳氧化硅（SiOC）陶瓷前体在CBCF基体上原位生长。合成的多尺度增强材料包括微米尺度的SiOC陶瓷和纳米尺度的SiC纳米线，主要归因于SiOC相的初始相分离以及随后的SiO和C相的固相反应。与SiOC / CBCF复合材料相比，由于SiC纳米线的拉出和桥接行为，所得的3D SiC纳米线/ SiOC / CBCF混合结构表现出高的挠曲/拉伸强度和断裂应变。这一一步过程提供了一种可行的方法来合成3D SiC纳米线，以增强和增韧SiOC改性的CBCF复合材料。