Electron channeling contrast imaging (ECCI) was applied by precisely controlling the the primary electron beam incident direction of the crystal plane in scanning electron microscope (SEM), and the dislocation contrast in steel materials was investigated in detail via SEM/ECCI. The dislocation contrast was observed near a channeling condition, where the incident electron beam direction of the crystal plane varied, and the backscattered electron intensity reached a local minimum. Comparing the dislocation contrasts in the visualized electron channeling contrast (ECC) images and transmission electron microscope (TEM) images, the positions of all dislocation lines were coincident. During the SEM/ECCI observation, the dislocation contrast varied depending on the incident electron beam direction of the crystal plane and accelerating voltages, and optimal conditions existed. When the diffraction condition g and the Burgers vector b of dislocation satisfied the condition g b = 0, the screw dislocation contrast in the ECC image disappeared. An edge dislocation line was wider than a screw dislocation line. Thus, the SEM/ECCI method can be used for dislocation characterization and the strain field evaluation around dislocation, like the TEM method. The depth information of SEM/ECCI, where the channeling condition is strictly satisfied, can be obtained from dislocation contrast deeper than 5ξg, typically used for depth of SEM/ECCI.

中文翻译：

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精确控制电子束入射方向的电子沟道对比成像法观察和定量分析钢材中的位错

通过在扫描电子显微镜（SEM）中精确控制晶面的一次电子束入射方向，应用电子通道衬度成像（ECCI），并通过SEM/ECCI详细研究钢材中的位错衬度。在沟道条件附近观察到位错对比度，其中晶面的入射电子束方向发生变化，并且背散射电子强度达到局部最小值。比较可视化电子通道衬度（ECC）图像和透射电子显微镜（TEM）图像中的位错对比度，所有位错线的位置都是一致的。在SEM/ECCI观察过程中，位错对比度根据晶面的入射电子束方向和加速电压而变化，并且存在最佳条件。当衍射条件g和位错伯格斯矢量b满足条件gb = 0时，ECC图像中的螺旋位错对比度消失。刃型位错线比螺型位错线宽。因此，SEM/ECCI 方法可以像 TEM 方法一样用于位错表征和位错周围的应变场评估。严格满足沟道条件的SEM/ECCI的深度信息可以从深于5νg的位错对比度获得，通常用于SEM/ECCI的深度。