Atomistic modeling of carbon Cottrell atmospheres in bcc iron
Atomistic modeling of carbon Cottrell atmospheres in bcc iron
复制标题
BCC 铁中碳 Cottrell 气氛的原子模拟
DOI：
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
C. Domain
中科院分区：
文献类型：
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作者：
R. Veiga;M. Perez;C. Becquart;C. Domain
原子模拟与EAM原子间势被用来评估bcc铁中的碳位错结合能。这些结合能，然后被用来计算在附近的边缘和螺位错间隙网站的占用概率。由于碳-碳相互作用的饱和浓度也估计在位错核心的原子模拟，并作为一个Cottrell气氛中的碳浓度的上限。我们获得了10 ± 1原子%的最大浓度C在T = 0 K的范围内的半径为1 nm的位错线。线缺陷周围的空间碳分布表明，与刃位错相关的Cottrell气氛比螺位错周围的更致密，这与Cochardt及其同事的经典模型的预测相反。此外，本文的Cottrell大气模型与文献中的三维原子探针数据在定量上是合理的雅阁。
Atomistic simulations with an EAM interatomic potential were used to evaluate carbon–dislocation binding energies in bcc iron. These binding energies were then used to calculate the occupation probability of interstitial sites in the vicinity of an edge and a screw dislocation. The saturation concentration due to carbon–carbon interactions was also estimated by atomistic simulations in the dislocation core and taken as an upper limit for carbon concentration in a Cottrell atmosphere. We obtained a maximum concentration of 10 ± 1 at.% C at T = 0 K within a radius of 1 nm from the dislocation lines. The spatial carbon distributions around the line defects revealed that the Cottrell atmosphere associated with an edge dislocation is denser than that around a screw dislocation, in contrast with the predictions of the classical model of Cochardt and colleagues. Moreover, the present Cottrell atmosphere model is in reasonable quantitative accord with the three-dimensional atom probe data available in the literature.