Microstructural evolution and oxidation resistance of polyacrylonitrile-based carbon fibers doped with boron by the decomposition of B4C
作者：Wang H, Guo Q, Yang J, Liu Z, Zhao Y, Li J, Feng Z, Liu L.
關鍵字：boron doping, carbon fibers, oxidation resistance
論文來源：期刊
具體來源：Carbon, 2013, 56(1): 296-308.
發表時間：2013年
Boron (B) was doped into polyacrylonitrile-based carbon ?bers (CFs) in various contents by exposing the CFs in a vapor of B by the decomposition of B 4 C. The structural evolution of B-doped CFs on different B concentrations and heat-treatment temperatures was studied using scanning electron microscope, transmission electron microscope, X-ray diffraction and Raman spectroscopy. It was found that introducing B changed the morphology of the CFs. At high temperatures, the strong erosion of B vapor, not only changed the primary structure of CFs, but also produced more ?aws. Structural analysis indicates that B is mostly substitutionally bonded within the graphene sheet regardless of the experimental conditions. As increasing from 2200 to 2600 C in the graphite crucible containing 10% B 4 C, the concentration of substitutional B increased progressively from 0.81 to 2.57 at.%. Thermogravimetric analysis revealed that B-doping greatly improved oxidation resistance of the CFs with the oxidation onset temperature increasing from 640 C (0 at.% B doped,2.1% weight loss) to about 800 C (3.65 at.% B doped, 0.3% weight loss). The correlation between structural evolution and oxidation resistance of B-doped CFs provides a new route for fabricating the CFs with oxidation resistance up to 800 C.