摘要
Novel headstand pyrocarbon cones （HPCs） with hollow structure were developed on the surfaces of pyrocarbon layers of the carbon/carbon （C/C） composites at 650-750 °C by the electromagnetic-field-assisted chemical vapor deposition in the absence of catalysts. The fine microstructures of the HPCs were characterized by high-resolution transmission electron microscopy. The results show that the textural features of the HPCs directly transfer from turbostratic structure in roots to a well-ordered high texture in stems. And the degree of high texture ordering decreases gradually from the stem to the tail of the HPCs. The formation mechanism of the HPCs was inferred as the comprehensive effect of polarization induction on electromagnetic fields and particle-filler property under disruptive discharge.
采用电磁场辅助CVD法,在650～750°C的温度下制备出具有中空结构的倒锥状热解炭。此类倒锥状热解炭生长在C/C复合材料中热解炭的表面。采用高分辨率透射电镜对倒锥状热解炭的内部结构进行精细表征。结果表明,倒锥状热解炭的内部织构呈现出从根部杂乱的缠绕织构直接到其紧邻茎部有序的高织构的变化趋势,而从其茎部至锥尾部区域,炭微晶结构有序化程度逐渐降低。倒锥状热解炭的形成机理可推测为是一种在强电磁场作用下的极化诱导效应和击穿放电作用下的颗粒填充效应的综合作用。
基金
Project (2011CB605801) supported by the National Basic Research Program of China
Project (2011M500127) supported by the China Postdoctoral Science Foundation
Projects (50802115, 51102089) supported by the National Natural Science Foundation of China
Project supported by the Postdoctoral Fund of the Central South University, China
