Effect of impurities on grain boundary cohesion in bcc iron

被引：67

作者：

Wachowicz, E. ^{[1
]}

Kiejna, A.

机构：

[1] Univ Wroclaw, Inst Expt Phys, PL-50204 Wroclaw, Poland

来源：

COMPUTATIONAL MATERIALS SCIENCE | 2008年 / 43卷 / 04期

关键词：

Density functional calculations; Grain boundary cohesion; Iron; Impurities; Embrittlement; Magnetic moments;

D O I：

10.1016/j.commatsci.2008.01.063

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

The effect of B, N and O impurities placed in interstitial and substitutional positions at symmetric Sigma 5(210) Fe grain boundary is studied by means of first principles calculations. Full relaxation of supercell shape and volume is applied which results in stable asymmetric grain boundaries, depending on the impurity and its position. In all cases the big shifts (0.47-2.33 angstrom) of grains with respect to each other are observed. The equilibrium distance between the grains is decreased for impurities in substitutional positions, and increased for atoms in interstitial sites, compared to the relaxed clean GB. We found that nitrogen both in interstitial and substitutional positions, and boron in substitutional position enhance cohesion while oxygen in both positions, and interstitial boron, are embrittlers. The magnetic moments of Fe atoms at clean grain boundary are remarkably increased compared to the bulk. They tend to the bulk value in the middle of the grain in an oscillatory way. (C) 2008 Elsevier B.V. All rights reserved.

引用

页码：736 / 743

页数：8

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