Interactions between carbon solutes and dislocations in bcc iron
Interactions between carbon solutes and dislocations in bcc iron
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DOI：
10.1016/j.actamat.2010.06.024
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发表时间：
2010-09
期刊：
影响因子：
9.4
通讯作者：
Y. Hanlumyuang;P. Gordon;T. Neeraj;D. Chrzan
中科院分区：
文献类型：
--
作者：
Y. Hanlumyuang;P. Gordon;T. Neeraj;D. Chrzan
从第一性原理出发，用两种方法计算了体心立方（bcc）铁中边位错和螺位错的碳溶质位错相互作用和溶质气氛。首先，利用基于电子结构的总能量法直接计算了C原子向Fe位错核偏析的畸变张量和弹性常数。其次，采用第一性原理法直接计算偏析能。两种方法的比较表明，除了弹性常数中已经反映的影响外，化学和磁性的影响并没有对偏析能做出主要贡献。由此预测的溶质气氛与原子探针测量结果很好地吻合。
Carbon solute–dislocation interactions and solute atmospheres for both edge and screw dislocations in body-centered cubic (bcc) iron are computed from first principles using two approaches. First, the distortion tensor and elastic constants entering Eshelby’s model for the segregation of C atoms to a dislocation core in Fe are computed directly using an electronic-structure-based the total energy method. Second, the segregation energy is computed directly via first-principles methods. Comparison of the two methods suggests that the effects of chemistry and magnetism beyond those already reflected in the elastic constants do not make a major contribution to the segregation energy. The resulting predicted solute atmospheres are in good agreement with atom probe measurements.