Grain-boundary activated pyramidal dislocations in nano-textured Mg by molecular dynamics simulation

The generalized-stacking-fault energies are calculated to illustrate the dissociation of hc ? ai dislocation on pyramidal I plane in magnesium. The c surfaces of f10 11g plane and its adjacent planes f30 34g and f30 32g are presented using Liu embedded-atom-method potential method, and one possible dissociation path of 1=3h11 23i dislocation on f1011g plane with minimum energy is predicted. Meanwhile, another two reasonable dissociation paths of 1=3h11 23i dislocation successively on f30 34g and f30 32g planes are also proposed. Moreover, based on molecular dynamics simulations of magnesium single crystals under c-axis compression, the possible slip path is further examined and discussed.

show abstract

“…The same EAM potential was used in Kim's work [30], but the dissociation was quite different. In the nano-textured magnesium, the hc ?…”

Section: Discussion On Different Pathsmentioning

confidence: 99%

Analysis on Dissociation of Pyramidal I Dislocation in Magnesium by Generalized-Stacking-Fault Energy

Guo

Tang

2015

Acta Metall. Sin. (Engl. Lett.)

View full text Add to dashboard Cite

show abstract

“…The c/a ratio of Mg is 1.623 close to the ideal value; thus the primary slip system of Mg is on the basal plane. MD simulation of polycrystalline Mg using an EAM potential [16] manifested the experimentally observed basal hai dislocation and tensile twinning behaviors [15]. Nanocrystalline materials are of particular interest because they have a large area of grain boundaries, which tend to be dislocation nucleation sites.…”

Section: Introductionmentioning

confidence: 97%

“…It was found that the stacking fault energy and, more importantly, the unstable stacking fault energy determine the dislocation behavior [11]. There has also been some work on hcp metals [14,15]. The c/a ratio of Mg is 1.623 close to the ideal value; thus the primary slip system of Mg is on the basal plane.…”

Section: Introductionmentioning

confidence: 99%

Deformation processes in polycrystalline Zr by molecular dynamics simulations

Noordhoek

Chernatynskiy

et al. 2015

Journal of Nuclear Materials

View full text Add to dashboard Cite

a b s t r a c tMolecular dynamics simulation is used to characterize the deformation behavior of polycrystalline Zr. The predictions of two different potentials, an embedded atom method potential and a charge optimized many body potential are compared. The experimentally observed prismatic dislocations, pyramidal dislocations and twinning behaviors are produced in the simulations of ½1 1 2 0 and [0 0 0 1] textured structures and in fully 3D structure simulations. The relationship between the generalized stacking fault energy and the mechanical properties is discussed. In particular we find that the different shapes of the generalized stacking-fault energy curve for the two different interatomic descriptions of Zr have a significant effect on the deformation mechanisms. The deformation behavior of Zr is compared with analogous simulations of deformation of polycrystalline Mg.

show abstract

“…It should be noted that, for the purpose of obtaining theoretical insight for such defected structures, there have been a lot of MD studies concerning twinning and dislocations in deformation [15][16][17][18]. Within the context of the effect of GB on plastic deformation of Mg like in the present study, polycrystalline MD models (though composed of nanosized grains) have been also investigated and those studies are giving many insights as for deformation mechanism around GB region [19][20][21][22][23].…”

Section: Introductionmentioning

confidence: 99%

Molecular Dynamics Study on Deformation Mechanism of Grain Boundaries in Magnesium Crystal: Based on Coincidence Site Lattice Theory

Saitoh

Kuramitsu

Sato

et al. 2018

Journal of Materials

View full text Add to dashboard Cite

As for magnesium (Mg) alloys, it has been noted that they are inferior to plastic deformation, but improvement in the mechanical properties by further refinement of grain size has been recently suggested. It means the importance of atomistic view of polycrystalline interface of Mg crystal. In this study, to discuss the deformation mechanism of polycrystalline Mg, atomistic grain boundary (GB) models by using coincidence site lattice (CSL) theory are constructed and are simulated for their relaxed and deformatted structures. First, GB structures in which the axis of rotation is in [1100] direction are relaxed at 10 Kelvin, and the GB energies are evaluated. Then, the deformation mechanism of each GB model under uniaxial tensile loading is observed by using the molecular dynamics (MD) method. The present MD simulations are based on embedded atom method (EAM) potential for Mg crystal. As a result, we were able to observe atomistically a variety of GB structures and to recognize significant difference in deformation mechanism between low-angle GBs and high-angle GBs. A close scrutiny is made on phenomena of dislocation emission processes peculiar to each atomistic local structure in high-angle GBs.

show abstract

Grain-boundary activated pyramidal dislocations in nano-textured Mg by molecular dynamics simulation

Cited by 47 publications

References 41 publications

Analysis on Dissociation of Pyramidal I Dislocation in Magnesium by Generalized-Stacking-Fault Energy

Analysis on Dissociation of Pyramidal I Dislocation in Magnesium by Generalized-Stacking-Fault Energy

Deformation processes in polycrystalline Zr by molecular dynamics simulations

Molecular Dynamics Study on Deformation Mechanism of Grain Boundaries in Magnesium Crystal: Based on Coincidence Site Lattice Theory

Contact Info

Product

Resources

About