Grain boundary-mediated plasticity in nanocrystalline nickel
Grain boundary-mediated plasticity in nanocrystalline nickel
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DOI：
10.1126/science.1098741
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发表时间：
2004-07-30
期刊：
影响因子：
56.9
通讯作者：
Mao, SX
中科院分区：
文献类型：
--
作者：
Shan, ZW;Stach, EA;Mao, SX
晶体材料的塑性行为主要由晶格位错的成核和运动控制。我们报告了平均晶粒尺寸约为10纳米的纳米晶镍薄膜的原位动态透射电子显微镜观察，结果表明晶界介导的过程已成为一种突出的变形模式。此外，在变形后，在单个晶粒中观察到了捕获的晶格位错。变形模式的这种变化是由位错的成核和运动控制的变形与扩散辅助晶界过程控制的变形之间依赖于晶粒尺寸的竞争引起的。
The plastic behavior of crystalline materials is mainly controlled by the nucleation and motion of lattice dislocations. We report in situ dynamic transmission electron microscope observations of nanocrystalline nickel films with an average grain size of about 10 nanometers, which show that grain boundary-mediated processes have become a prominent deformation mode. Additionally, trapped lattice dislocations are observed in individual grains following deformation. This change in the deformation mode arises from the grain size-dependent competition between the deformation controlled by nucleation and motion of dislocations and the deformation controlled by diffusion-assisted grain boundary processes.