Reducing grain boundary, dislocation line and vacancy formation energies by solute segregation. I. Theoretical background
Reducing grain boundary, dislocation line and vacancy formation energies by solute segregation. I. Theoretical background
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DOI：
10.1016/j.actamat.2007.05.047
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发表时间：
2007-09-01
期刊：
影响因子：
9.4
通讯作者：
Kirchheim, Reiner
中科院分区：
文献类型：
--
作者：
Kirchheim, Reiner
Gibbs吸附等温线和Wagner对表面和晶界过剩溶质的定义都被扩展到包括其他晶体缺陷，如位错和空位。利用一个适用于部分开放体系、对溶剂开放、对溶质原子封闭的热力学状态函数，可以得到广义的Gibbs吸附等温线。因此，溶质向位错和空位的偏析也会导致它们的形成能降低。将所提出的处理结果与统计力学或计算机模拟的结果进行了比较。特别关注了缺陷能是否会变为零或负值的问题。(C)2007年Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
The Gibbs adsorption isotherm and Wagner's definition of excess solute at surfaces and grain boundaries are both extended to include other crystalline defects, like dislocations and vacancies. By using a thermodynamic state function which is suitable for a partially open system, open with respect to solvent and closed with respect to solute atoms, a generalized Gibbs adsorption isotherm can be derived. Thus solute segregation to dislocations and vacancies gives rise to a reduction of their formation energies, too. The results of the presented treatment are compared with results stemming from statistical mechanics or computer simulations. Special attention is paid to the question whether defect energies might become zero or negative. (C) 2007 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.