Grain-Boundary Shear-Migration Coupling in Al Bicrystals. Atomistic Modeling

Карькина, Л. Е.; Kar’kin, I. N.; Кузнецов, А. Р.; Gornostyrev, Yu. N.

doi:10.1134/s1063783418100104

Cited by 5 publications

(10 citation statements)

References 28 publications

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“…To reveal the effect of segregation on the cohesive properties of GB in Al, we calculated the barriers for GB sliding and the energy of cleavage decohesion for GBs enriched with Zn or Mg solutes as well as for the GB in pure Al. As in Reference [38], here we determined the barrier for GB sliding as the change in energy when one part of the crystallite is shifted relative to the other along a given direction f in the GB plane (the plane is indicated by a dashed line in Figure 1c,d). The GB-SF energy, which characterizes the shear resistance of the considered GB in Al, was obtained in Reference [38] using molecular dynamics (MD) simulations.…”

Section: Resultsmentioning

confidence: 99%

“…As in Reference [38], here we determined the barrier for GB sliding as the change in energy when one part of the crystallite is shifted relative to the other along a given direction f in the GB plane (the plane is indicated by a dashed line in Figure 1c,d). The GB-SF energy, which characterizes the shear resistance of the considered GB in Al, was obtained in Reference [38] using molecular dynamics (MD) simulations. Although the use of interatomic potentials in MD simulations does not provide a completely reliable description, we think that the results in Reference [38] correctly reproduce the main topological features of the GB-SF surface (Figure 3).…”

Section: Resultsmentioning

confidence: 99%

“…The GB-SF energy, which characterizes the shear resistance of the considered GB in Al, was obtained in Reference [38] using molecular dynamics (MD) simulations. Although the use of interatomic potentials in MD simulations does not provide a completely reliable description, we think that the results in Reference [38] correctly reproduce the main topological features of the GB-SF surface (Figure 3). In particular, there are two easy GB sliding directions: O-O1 (along the tilt axis <100>) and O-A (at an angle to the tilt axis, Figure 3), for which the energy barrier is relatively small.…”

Section: Resultsmentioning

confidence: 99%

“…To determine the effect of segregation on GB strength, we calculated (i) the grain boundary generalized staking fault (GB-SF) energy to characterize the shear resistance inherent in this type of GB [38] and (ii) the GB decohesion energy E sep spent during the separation of the two crystallites in the direction perpendicular to the GB plane. The GB-SF energy was calculated as the energy variation E s f , when one crystallite is shifted relative to another in the GB plane by a given vector f; the resulting set of values E s f (f) forms a GB-SF surface.…”

Section: Methods Of Calculationsmentioning

confidence: 99%

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Effects of Zn and Mg Segregations on the Grain Boundary Sliding and Cohesion in Al: Ab Initio Modeling

Kuznetsov,

Karkina,

Gornostyrev

et al. 2021

Metals

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The formation of Zn and Mg segregations at a tilt Σ5{013} <100> grain boundary (GB) in Al and the effects of these solutes on deformation behavior of polycrystalline Al were investigated using ab initio total energy calculations. Using a step-by-step modeling of the segregation process, we found that the formation of a thick segregation layer of Zn at the GB is energetically preferable, while the formation of an atomically thin segregation layer is expected in the case of Mg. To reveal the effect of segregation on the cohesive properties of Al GBs, we calculated the energy of cleavage decohesion and the shear resistance for GB sliding. We show that the segregation of Zn results in a substantial decrease in barriers for GB sliding, while the segregation of Mg increases the barriers. The results obtained allow us to explain experimental findings and demonstrate a strong relationship between chemical bonding of solute atoms, their segregation ability, and GB strength.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Methods Of Calculationsmentioning

confidence: 99%

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Effects of Zn and Mg Segregations on the Grain Boundary Sliding and Cohesion in Al: Ab Initio Modeling

Kuznetsov,

Karkina,

Gornostyrev

et al. 2021

Metals

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“…This reconstruction involves GB coupled shear-migration processes, as it was discussed in Ref. [65]. For the solutes that have a bigger atomic size and accept electrons from the matrix (such as Mg), one can assume that the deformation contribution will be dominant.…”

Section: Discussionmentioning

confidence: 99%

Alloying Element Segregation and Grain Boundary Reconstruction, Atomistic Modeling

Карькина

Kar’kin

Кузнецов

et al. 2019

Metals

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Grain boundary (GB) segregation is an important phenomenon that affects many physical properties, as well as microstructure of polycrystals. The segregation of solute atoms on GBs and its effect on GB structure in Al were investigated using two approaches: First principles total energy calculations and the finite temperature large-scale atomistic modeling within hybrid MD/MC approach comprising molecular dynamics and Monte Carlo simulations. We show that the character of chemical bonding is essential in the solute–GB interaction, and that formation of directed quasi-covalent bonds between Si and Zn solutes and neighboring Al atoms causes a significant reconstruction of the GB structure involving a GB shear-migration coupling. For the solutes that are acceptors of electrons in the Al matrix and have a bigger atomic size (such as Mg), the preferred position is determined by the presence of extra volume at the GB and/or reduced number of the nearest neighbors; in this case, the symmetric GB keeps its structure. By using MD/MC approach, we found that GBs undergo significant structural reconstruction during segregation, which can involve the formation of single- or double-layer segregations, GB splitting, and coupled shear-migration, depending on the details of interatomic interactions.

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Effect of Alloying Element Segregations on the Grain Boundary Sliding in Al–Mg and Al–Ni Alloy Bicrystals: Atomistic Modeling

Карькина

Kar’kin

Gornostyrev

2020

Phys. Metals Metallogr.

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Grain-Boundary Shear-Migration Coupling in Al Bicrystals. Atomistic Modeling

Cited by 5 publications

References 28 publications

Effects of Zn and Mg Segregations on the Grain Boundary Sliding and Cohesion in Al: Ab Initio Modeling

Effects of Zn and Mg Segregations on the Grain Boundary Sliding and Cohesion in Al: Ab Initio Modeling

Alloying Element Segregation and Grain Boundary Reconstruction, Atomistic Modeling

Effect of Alloying Element Segregations on the Grain Boundary Sliding in Al–Mg and Al–Ni Alloy Bicrystals: Atomistic Modeling

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