Multiscale modeling of point defect interactions in Fe–Cr alloys
Multiscale modeling of point defect interactions in Fe–Cr alloys
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DOI：
10.1016/j.jnucmat.2008.12.092
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发表时间：
2009-04
影响因子：
3.1
通讯作者：
Kwan L. Wong;Hyon-Jee Lee;J. Shim;B. Sadigh;B. Wirth
中科院分区：
文献类型：
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作者：
Kwan L. Wong;Hyon-Jee Lee;J. Shim;B. Sadigh;B. Wirth
铁素体/马氏体合金在聚变中子辐照环境下的预测性能模型需要了解与Cr的点缺陷相互作用，这可以通过多尺度建模方法进行研究。利用finnis - sinclair型电位进行分子动力学模拟，研究了间隙的扩散，发现Cr和间隙之间的吸引和排斥结合的极值改变了间隙迁移的特征和Cr- fe扩散比。通过从头算确定了空位- Cr相互作用，这些计算揭示了Cr和Fe之间复杂的电子和磁相互作用。利用空位机制，利用LeClaire多频模型和动力学晶格蒙特卡罗模型，用ab-initio值计算了Cr- Fe的扩散比，两者都表明Cr的扩散速度快于Fe。本文讨论了BCC Fe-Cr合金中Cr在晶界处的辐射偏析问题。
Predictive performance models of ferritic/martensitic alloys in fusion neutron irradiation environments require knowledge of point defect interactions with Cr, which can be investigated by a multiscale modeling approach. Molecular dynamics simulations, using Finnis–Sinclair-type potentials, have been used to investigate the interstitial diffusion and reveal that the extremes of attractive and repulsive binding between Cr and interstitials change the characteristics of interstitial migration and the Cr-to-Fe diffusivity ratio. Ab-initio calculations have been performed to determine the vacancy–Cr interactions, and these calculations reveal complex electronic and magnetic interactions between Cr and Fe. The ab-initio values have been used to calculate the Cr-to-Fe diffusivity ratio by a vacancy mechanism using the LeClaire multi-frequency model and a kinetic lattice Monte Carlo model, both of which indicate that Cr diffuses faster than Fe. The modeling results are discussed in the context of the radiation-induced segregation of Cr at grain boundaries in BCC Fe–Cr alloys.