Tunable chemical complexity to control atomic diffusion in alloys
Tunable chemical complexity to control atomic diffusion in alloys
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DOI：
10.1038/s41524-020-0306-9
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发表时间：
2020-04
影响因子：
9.7
通讯作者：
Y. Osetsky;A. Barashev;L. Béland;Z. Yao;Keyvan Ferasat;Yanwen Zhang
中科院分区：
文献类型：
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作者：
Y. Osetsky;A. Barashev;L. Béland;Z. Yao;Keyvan Ferasat;Yanwen Zhang
在这篇文章中，我们报道了对Ni-Fe随机合金中化学偏置扩散的新的基本理解，这种扩散是由内在的可量化的化学复杂性所调节/控制的。开发耐辐射合金一直是一个长期存在的挑战。在这里，我们展示了如何利用固有的化学复杂性来指导原子扩散和抑制辐射损伤。以辐射效应中最重要的缺陷间隙原子(IA)扩散为例，说明了化学复杂性的影响。我们用μ-S尺度的分子动力学研究了原子间相互作用在浓缩Ni-Fe合金中的缓慢扩散和渗流。我们建立了一个平均场扩散模型，考虑了迁移缺陷能量性质对扩散渗流的影响，并用一种新的动力学蒙特卡罗方法对其进行了验证。我们证明了合金中IA组态基态能量的局域变化，反映了合金成分之间的化学差异，驱动了原子扩散的渗流效应。渗流、化学偏向和缓慢扩散是与多元合金固有的化学复杂性直接相关的现象。
In this paper we report a new fundamental understanding of chemically-biased diffusion in Ni–Fe random alloys that is tuned/controlled by the intrinsic quantifiable chemical complexity. Development of radiation-tolerant alloys has been a long-standing challenge. Here we show how intrinsic chemical complexity can be utilized to guide the atomic diffusion and suppress radiation damage. The influence of chemical complexity is shown by the example of interstitial atom (IA) diffusion that is the most important defect in radiation effects. We use μs-scale molecular dynamics to reveal sluggish diffusion and percolation of IAs in concentrated Ni–Fe alloys. We develop a mean field diffusion model to take into account the effect of migrating defect energy properties on diffusion percolation, which is verified by a new kinetic Monte Carlo approach addressing detailed processes. We demonstrate that the local variations in the ground state energy of IA configurations in alloys, reflecting the chemical difference between alloying components, drives the percolation effects for atomic diffusion. Percolation, chemically-biased and sluggish diffusion are phenomena that are directly related to the chemical complexity intrinsically to multicomponent alloys.