Molecular dynamics study of strengthening by nanometric void and Cr alloying in Fe
Molecular dynamics study of strengthening by nanometric void and Cr alloying in Fe
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Fe中纳米空隙和Cr合金化强化的分子动力学研究
DOI：
10.1016/j.jnucmat.2013.04.045
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
S. M. H. Haghighat
中科院分区：
文献类型：
--
作者：
R. Schäublin;S. M. H. Haghighat
铁素体钢是未来聚变反应堆结构部件的主要候选材料。由于其结构的复杂性，模拟工作大多集中在α-Fe或Fe-Cr合金等材料的基相上。本文采用分子动力学模拟方法研究了铬对体心立方Fe-Cr合金塑性的影响。比较了最近用于Fe-Fe相互作用的原子间相互作用势，即Chiesa 2009和Malerba 2010，并与该领域广泛使用的Ackland 1997、Mendelev 2003和Ackland 2004进行了比较。对于铁-铬系统，采用了Ackland 2004的Fe-Fe势和Olsson 2005的Fe-Cr和Cr-Cr相互作用势。首先，通过研究10℃下2 nm空穴与刃位错的相互作用，评估了最近的Fe-Fe原子间相互作用势；其次，研究了Fe中的Cr对0~100at.%范围内刃位错迁移率的影响。其滑动应力随铬含量的增加而增大，当铬含量达到约60at.%时，其滑动应力减小。在60℃下观察到的高流动应力与铬的本征力学性能无关，而是与诱发的晶格变形有关。
Ferritic steels are the main candidates for the structural components of future fusion reactors. Because of the complexity of their structure, most of the simulation works are focused on the base phase of these materials such as alpha-Fe or Fe–Cr alloy. In this work molecular dynamics (MD) simulation is used to investigate the influence of chromium on the plasticity of bcc Fe–Cr alloy. Recent interatomic potentials for the Fe–Fe interactions are compared, namely Chiesa 2009 and Malerba 2010, with a comparison to Ackland 1997, Mendelev 2003 and Ackland 2004, widely used in this field. For the Fe–Cr system the potentials of Ackland 2004 for Fe–Fe and of Olsson 2005 for Fe–Cr and Cr–Cr interactions are used. Firstly, the recent Fe–Fe interatomic potentials are assessed by studying the interaction of the edge dislocation with a 2 nm void at 10 K. Secondly, the impact of Cr in Fe on the mobility of an edge dislocation for contents between 0 and 100 at.% is studied. It appears that its glide stress increases with Cr content up to about 60 at.%, and then decreases. The high flow stress observed at 60 at.% Cr does not relate to Cr intrinsic mechanical properties, but to the induced lattice distortion.