Dislocation processes in the deformation of nanocrystalline aluminium by molecular-dynamics simulation
Dislocation processes in the deformation of nanocrystalline aluminium by molecular-dynamics simulation
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DOI：
10.1038/nmat700
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发表时间：
2002-09-01
期刊：
影响因子：
41.2
通讯作者：
Gleiter, H
中科院分区：
文献类型：
--
作者：
Yamakov, V;Wolf, D;Gleiter, H
纳米晶材料（即晶粒尺寸小于100 nm的多晶）的机械性能仍有争议。虽然人们普遍认为这些材料的内在变形行为是由位错和晶界过程之间的相互作用引起的，但对具体的变形机制知之甚少。在这里，我们使用大规模的分子动力学模拟来阐明这种复杂的相互作用，在室温下的模型纳米晶铝微结构的塑性变形。我们表明，在粗晶铝，机械孪生可能发挥重要作用，在纳米晶铝的变形行为。我们的研究结果表明，这种类型的模拟，现在已经先进的水平，它提供了一个强大的新的工具，阐明和量化的程度上的细节不可能的实验控制复杂的位错和晶界过程中严重变形的材料与亚微米晶粒尺寸的原子级机制。
The mechanical behaviour of nanocrystalline materials (that is, polycrystals with a grain size of less than 100 nm) remains controversial. Although it is commonly accepted that the intrinsic deformation behaviour of these materials arises from the interplay between dislocation and grain-boundary processes, little is known about the specific deformation mechanisms. Here we use large-scale molecular-dynamics simulations to elucidate this intricate interplay during room-temperature plastic deformation of model nanocrystalline aluminium microstructures. We demonstrate that, in contrast to coarse-grained aluminium, mechanical twinning may play an important role in the deformation behaviour of nanocrystalline aluminium. Our results illustrate that this type of simulation has now advanced to a level where it provides a powerful new tool for elucidating and quantifying-in a degree of detail not possible experimentally-the atomic-level mechanisms controlling the complex dislocation and grain-boundary processes in heavily deformed materials with a submicrometre grain size.