Basal-plane stacking fault energy of hexagonal close-packed metals based on the Ising model
Basal-plane stacking fault energy of hexagonal close-packed metals based on the Ising model
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基于Ising模型的六方密排金属基面堆垛层错能
DOI：
10.1016/j.actamat.2012.10.023
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发表时间：
2013-02-01
期刊：
影响因子：
9.4
通讯作者：
Yang, Rui
中科院分区：
文献类型：
--
作者：
Hu, Qing-Miao;Yang, Rui
层错能在金属的塑性变形中起着重要的作用。与面心立方金属相比，六方密堆积金属(HCP)的自洽场效应在文献中报道较少。本文在Ising模型的框架下，根据层间相互作用能，导出了四种类型(I-1、I-2、E和T-2)的HCP金属基面自由能的表达式。然后用第一原理全势增广平面波方法从四个原型的总能量中提取层间相互作用能来计算14种HCP金属的SFE。结果表明，根据层间相互作用能的不同，hcp金属可以分为三种类型。在本研究涉及的所有六氯酚金属中，I-1的SFE最低，而E的SFE最高。主滑移系(0 0 0 1)[杆0上1 1(2)]的金属(镁、钴、锌、镉)一般具有较低的基面应力强度因子。I-1和T-2SFE随双六方密排结构和HCP结构的能量差而线性增加，而I-2和E SFE随短周期孪晶和HCP结构的能量差而线性增加，表明第三近邻原子层之间的相互作用能对SFE的贡献很小。除Be、Co、Tc和Re外，SFE还与结合能密度(单位体积的结合能)相关。(C)2012 Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
Stacking fault energy (SFE) plays an important role in the plastic deformation of metals. As compared to those of face-centered cubic metals, the SFEs of hexagonal close-packed (hcp) metals are less reported in literature. In this paper, we derive the expressions of four types (I-1, I-2, E and T-2) of basal plane SFEs of hcp metals in terms of the interlayer interaction energies within the framework of the Ising model. The SFEs of 14 kinds of hcp metals are then evaluated with the interlayer interaction energies extracted from the total energies of four prototypes calculated by using the first-principles full-potential augmented plane-wave method. We show that the hcp metals can be divided into three types according to their interlayer interaction energies. For all the hcp metals involved in this study, I-1 has the lowest SFE, whereas E has the highest. The metals (Mg, Co, Zn and Cd) with principal slip system (0 0 0 1)[1 1 (2) over bar 0] generally have low basal plane SFEs. The I-1 and T-2 SFEs increase linearly with the energy difference between double hexagonal close-packed and hcp structures, whereas the I-2 and E SFEs increase linearly with the energy difference between the short-period twin and hcp structures, indicating a trivial contribution of the interaction energy between atomic layers over third nearest neighbors to the SFEs. The SFEs also correlate with the cohesive energy density (cohesive energy of unit volume) with the exception of Be, Co, Tc and Re. (C) 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.