Direct observation of strain-stored grains in electrodeposited nanocrystalline Ni-W alloys by low-angle annular dark field diffraction contrast imaging
Direct observation of strain-stored grains in electrodeposited nanocrystalline Ni-W alloys by low-angle annular dark field diffraction contrast imaging
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DOI：
10.1016/j.scriptamat.2019.03.001
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发表时间：
2019-06
影响因子：
6
通讯作者：
I. Matsui;Y. Takigawa;Takahisa Yamamoto
中科院分区：
文献类型：
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作者：
I. Matsui;Y. Takigawa;Takahisa Yamamoto
通过低角度环形暗场扫描透射电子显微镜（LAADF-STEM）评估了电沉积纳米晶 Ni-W 合金晶粒内部的纳米结构。 LAADF 成像显示出足够的对比度，可以灵敏地反映晶体取向的扭曲。常规 STEM 图像显示晶粒尺寸约为 30 nm 的纳米晶体结构。通过结合这些模式，LAADF-STEM 图像捕获了纳米颗粒内晶体取向的变化。此外，傅里叶变换处理的图案显示，即使在沉积状态下，晶格也已经扭曲。应变存储晶粒的重要性根据其潜在的机械性能进行了讨论。
Nanostructures of grain interior in electrodeposited nanocrystalline Ni-W alloys were evaluated by low-angle annular dark-field scanning transmission electron microscopy (LAADF-STEM). LAADF imaging displayed sufficient contrast to sensitively reflect distortions of the crystal orientation. Conventional STEM images showed the nanocrystalline structures with grain size of ~30 nm. By combining these modalities, LAADF-STEM images captured variations in the crystal orientation within nanograins. In addition, Fourier transform-processed patterns revealed that the crystal lattice was already distorted even in the as-deposited state. The importance of strain-stored grains is discussed in terms of their potential mechanical properties.