Analyzing carbon fiber structures observed by helium ion microscopy and their mechanical properties
Analyzing carbon fiber structures observed by helium ion microscopy and their mechanical properties
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分析氦离子显微镜观察到的碳纤维结构及其机械性能
DOI：
10.1016/j.cartre.2021.100055
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
A. Naskar
中科院分区：
文献类型：
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作者：
Xinzhang Zhou;A. Belianinov;A. Naskar
在这项工作中，我们首次展示了通过氦离子显微镜 (HIM) 在高放大倍率下观察到的碳纤维断裂表面图像，旨在捕获尺寸在 10 nm 至 100 nm 之间的缺陷。各种商用碳纤维的标称临界缺陷尺寸是根据格里菲斯方程计算的，其临界缺陷尺寸分布是根据威布尔强度分布计算的。标准模量 (~230 GPa)、中间模量 (~280 GPa)、高模量 (>350 GPa) 和超高强度 (>6.8 GPa) 碳纤维的 HIM 图像显示出具有对比的微观结构。一些三维 (3D) 结构特征，如结晶片、薄片和非晶材料组，以前从未被扫描电子显微镜 (SEM) 捕获过。此外，通过单丝测试方法对代表性的中间模量碳纤维进行了机械测试，其强度特性与 HIM 观察到的结构特征相关。 HIM 成像提供了一种新的、可重复且可行的技术来分析碳纤维的原始 3D 纳米结构。
In this work we present images of carbon fiber fractured surfaces observed for the first time by Helium Ion Microscopy (HIM) at high magnifications, aiming to capture defects ranging in size between 10 nm and 100 nm. Nominal critical defect sizes of various commercial carbon fibers were calculated from the Griffith Equation and their critical defect size distributions were calculated from their Weibull strength distributions. HIM images of the carbon fibers with the standard modulus (~230 GPa), intermediate modulus (~280 GPa), high modulus (>350 GPa) and ultra-high strength (>6.8 GPa) are shown to have contrasting microstructures. Some of the three dimensional (3D) structural features, like crystalline sheets, flakes, and sets of amorphous material, have not been previously captured by Scanning Electron Microscopy (SEM). Furthermore, a representative intermediate modulus carbon fiber was mechanically tested by the single filament test method and its strength characteristics were corelated to structural features observed by HIM. HIM imaging offers a new, reproducible, and feasible technique to analyze the original 3D nanostructures of carbon fibers.