The microstructure and elctrical resistivity of near-stoichiometric SiC fiber

2nd International Symposium on Application of Materials Science and Energy Materials

材料科学;能源学

Bai, Weicheng^1 ; Jian, Ke^1

Science and Technology On Advanced Ceramic Fibers and Composites Laboratory, National University of Defense Technology, Changsha

410073, China^1

关键词: Advanced composites;    Carbon-rich layers;    Defense technologies;    Nano-crystallines;    Near stoichiometric;    Orders of magnitude;    Porosity and pore size;    Skin-core structure;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/490/2/022057/pdf
DOI  :  10.1088/1757-899X/490/2/022057

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

SiC fibers with electrical resistivity of different orders of magnitude are of great interest for the fabrication of advanced composites with electromagnetic wave absorbent performance as both structural and functional materials. KD-S and KD-SA fiber produced by National University of Defense Technology were oxidized at 800°C air to get KD-OS and KD-OSA respectively. The microstructure and electrical resistivity of near-stoichiometric SiC fibers (KD-S, KD-OS, KD-SA, KD-OSA) were analyzed and evaluated in detail. The SiC fibers consisted of β-SiC nanocrystallines and free carbon. Apart from KD-OSA, these SiC fibers exhibited a uniquely specific skin-core structure with thin carbon-rich layer of about 25 nm on their surfaces. So the electrical resistivity of KD-OSA was 2961.7Ω•cm which was much higher than the rest of the fibers. After testing the porosity and pore size distribution of the fibers, we discover that the pore structure of KD-SA is more abundant than that of KD-S and KD-OS to the extent that the resistivity of KD-SA is higher than that of KD-S and KD-OS.