The modified embedded-atom method interatomic potentials and recent progress in atomistic simulations

Lee, Byeong-Joo; Ko, Won-Seok; Kim, Hyun-Kyu; Kim, Eunha

doi:10.1016/j.calphad.2010.10.007

Cited by 153 publications

(102 citation statements)

References 58 publications

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“…He (1s 2 ) has a closed-shell electronic structure making it is reasonable to assume that He does not interact with Fe as indicated by low charge transfers of 0.18 electrons from Fe. Dissolution energy of C at the O-site is calculated to be 1.17 eV which has good agreement with molecular dynamic results of 1.22 eV [22]. N is stabilized at the O-site having 0.89 eV of dissolution energy which is not previously reported.…”

Section: H He C and N In α-Fesupporting

confidence: 74%

Physical properties of α-Fe upon the introduction of H, He, C, and N

Sakuraya

Takahashi

Wang

et al. 2014

Solid State Communications

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The effects of impurities of H, He, C, and N in α-Fe are investigated in terms of electronic structures using the density functional theory. Calculations reveal that H and He are stable at the T-site while C and N are stable at the O-site within α-Fe. The local strain field by H, He, C, and N in α-Fe cause structural elongation. Furthermore, the decrease of magnetic moment of Fe upon the introduction of C and N are found where the charge transfer is responsible. H, He, C, and N affect the electronic structure of α-Fe and change the fundamental physical properties of α-Fe.

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Section: H He C and N In α-Fesupporting

confidence: 74%

Physical properties of α-Fe upon the introduction of H, He, C, and N

Sakuraya

Takahashi

Wang

et al. 2014

Solid State Communications

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“…We performed molecular dynamics simulations by using the modified embedded-atom method of interatomic potentials (29,30). For deformation simulations, supercell structures of about 54 × 54 × 48 ∼ 140,000 atoms were constructed with a 2D-periodic boundary condition in which extrinsic effects from grain boundaries and surfaces were avoided.…”

Section: Methodsmentioning

confidence: 99%

“…Namely, in materials under a uniaxial shear stress, grains experience different load conditions and thus may activate different deformation modes, depending on their orientation. Here, we used molecular dynamics simulations (29,30) to address the grain orientation effect on the deformation modes of fcc metals. …”

mentioning

confidence: 99%

Theory for plasticity of face-centered cubic metals

Koo

Lee

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

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The activation of plastic deformation mechanisms determines the mechanical behavior of crystalline materials. However, the complexity of plastic deformation and the lack of a unified theory of plasticity have seriously limited the exploration of the full capacity of metals. Current efforts to design high-strength structural materials in terms of stacking fault energy have not significantly reduced the laborious trial and error works on basic deformation properties. To remedy this situation, here we put forward a comprehensive and transparent theory for plastic deformation of face-centered cubic metals. This is based on a microscopic analysis that, without ambiguity, reveals the various deformation phenomena and elucidates the physical fundaments of the currently used phenomenological correlations. We identify an easily accessible single parameter derived from the intrinsic energy barriers, which fully specifies the potential diversity of metals. Based entirely on this parameter, a simple deformation mode diagram is shown to delineate a series of convenient design criteria, which clarifies a wide area of material functionality by texture control.planar fault | twinning | slip | molecular dynamics E lastic deformation of metals is fully described by Hooke's law, connecting stress and strain via the usual elastic parameters. In contrast, plasticity is a property that originates from dislocations and involves transitions over various competing energy barriers. A phenomenological description of the plastic regime based merely on the stacking fault energy (SFE) has been widely used by material scientists (1-11), even though it is not at all clear whether such an equilibrium property can really capture the complexity of plastic deformation. To try to mend this situation, researchers have introduced the so-called generalized planar fault (GPF) energy, which comprises several intrinsic energy barriers (IEBs) and thus provides detailed information on the deformation process itself (12, 13). Nevertheless, the GPF energy has not yet been fully recognized because of its inherent difficulty in experimental validation (14). In the present paper we solve this and introduce an approach that is fully transparent, where there are no such ambiguities.Face-centered cubic (fcc) metals possess three distinct deformation mechanisms: stacking fault (SF), twinning (TW), and full slip (SL) (2,(5)(6)(7)15). Many studies tried to relate the deformation of fcc metals to the GPF energy. For example, the competition between TW and SL was explained by a relative change between the intrinsic energy barriers, assuming the activation of the lowest barrier mode (16)(17)(18). However, such a simplified picture was found to be inadequate to elucidate the simultaneous activation of different modes seen in experiments (2,5,6,15). It has emerged that additional factors should be taken into account in conjunction with the GPF energy for describing the deformation behavior.The microstructure of materials, such as grain size and orientation, is known to in...

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“…Such process is viable on some materials but not the others, and can be questionable in reproducibility. As such, a large portion of modern understanding on the topic of surface energy is obtained via computational methods, such as density-function theories (DFT) or embedded-20 atom methods (EAM) type semi-empirical approaches [4,5,6,7,8,9,10,11,12,13,14,15,16,17] . However, the computational costs of these methods raise dramatically for atomically complex surfaces and thus render them less suitable for the investigation of the full anisotropy of surface energy.…”

Section: Introductionmentioning

confidence: 99%

Surface energy and its anisotropy of hexagonal close-packed metals

Luo

Qin

2014

Surface Science

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The absolute unrelaxed surface energy and its full orientation-dependent behaviour of 13 HCP metals are studied via a broken-bond base geometric model. The model is integrated with the Rose-Vinet universal potential to investigate arbitrary orientations which are not assessable by other methods. Using only three materials constants, the calculated results show only marginal discrepancies with reported experimental values, except for divalent sp metals Mg, Zn and Cd where the calculated values are lower by a factor of 2. Stereographic projections of all 13 metals show global minimum on (0001) pole with an overall anisotropy of 15% to 21%. The equilibrium crystal shape of HCP is found to be truncated hexagonal bi-prismatic, with (0001) always favoured but the bi-prismatic facets vary from one metal to another. All projection patterns show strong six-fold symmetries but are unique for every element. The patterns are found to be largely determined by an anharmonicity factor η. Best agreement with experimental findings are found for Be, Sc, Ti,Y, Zr and Hf which possess comparatively low η. We believe the stereographic projections of these elements are the more representative for HCP metals.

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The modified embedded-atom method interatomic potentials and recent progress in atomistic simulations

Cited by 153 publications

References 58 publications

Physical properties of α-Fe upon the introduction of H, He, C, and N

Physical properties of α-Fe upon the introduction of H, He, C, and N

Theory for plasticity of face-centered cubic metals

Surface energy and its anisotropy of hexagonal close-packed metals

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