Department of Materials Science and Engineering, Boise State University, 1910 University Drive, Boise, ID 83725, USA.
Microsc Microanal. 2012 Apr;18(2):272-8. doi: 10.1017/S1431927611012360. Epub 2012 Jan 23.
This article reports the microstructural characteristics of various petroleum and pitch based nuclear graphites (IG-110, NBG-18, and PCEA) that are of interest to the next generation nuclear plant program. Bright-field transmission electron microscopy imaging was used to identify and understand the different features constituting the microstructure of nuclear graphite such as the filler particles, microcracks, binder phase, rosette-shaped quinoline insoluble (QI) particles, chaotic structures, and turbostratic graphite phase. The dimensions of microcracks were found to vary from a few nanometers to tens of microns. Furthermore, the microcracks were found to be filled with amorphous carbon of unknown origin. The pitch coke based graphite (NBG-18) was found to contain higher concentration of binder phase constituting QI particles as well as chaotic structures. The turbostratic graphite, present in all of the grades, was identified through their elliptical diffraction patterns. The difference in the microstructure has been analyzed in view of their processing conditions.
本文报道了下一代核电厂计划感兴趣的各种石油和沥青基核石墨（IG-110、NBG-18 和 PCEA）的微观结构特征。明场透射电子显微镜成像用于识别和理解构成核石墨微观结构的不同特征，如填充颗粒、微裂纹、结合相、蔷薇形喹啉不溶物（QI）颗粒、混乱结构和乱层石墨相。发现微裂纹的尺寸从几纳米到几十微米不等。此外，发现微裂纹中填充有未知来源的无定形碳。发现基于沥青焦的石墨（NBG-18）含有更高浓度的结合相，构成 QI 颗粒和混乱结构。通过它们的椭圆形衍射图案鉴定了所有等级中存在的乱层石墨。根据它们的加工条件分析了微观结构的差异。
