Overview No. 127The role of the grain boundary plane in cubic polycrystals

Randlè, Valerie

doi:10.1016/s1359-6454(97)00338-8

Cited by 135 publications

(65 citation statements)

References 72 publications

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“…[5]-i.e., a smaller GB unit cell-which in turn may lead to lower GB energy [50]. The spacing between any intrinsic GB defects, such as misfit dislocations [15,51], may also be different in our models than in the experiments.…”

Section: Atomic Models Of Selected Grain Boundariesmentioning

confidence: 96%

Non-coherent Cu grain boundaries driven by continuous vacancy loading

Demkowicz

2015

J Mater Sci

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We use atomistic modeling to study the response of three non-coherent grain boundaries (GBs) in Cu to continuous loading with vacancies. Our simulations yield insights into the structure and properties of these boundaries both near and far from thermal equilibrium. We find that GB energies vary periodically as a function of the number of vacancies introduced. Each GB has a characteristic minimum energy state that recurs during continuous vacancy loading, but in general cannot be reached without removing atoms from the boundary. There is no clear correlation of GB energies with GB specific excess volumes or stresses during vacancy loading. However, GB stresses increase monotonically with specific excess volumes. Continuous vacancy loading gives rise to GB migration and shearing, despite the absence of applied loads. Successive vacancies introduced into some of the boundaries accumulate at the cores of what appear to be generalized vacancy dislocation loops. We discuss the implications of these findings for our understanding of grain boundary sink efficiencies under light ion irradiation.

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Section: Atomic Models Of Selected Grain Boundariesmentioning

confidence: 96%

Non-coherent Cu grain boundaries driven by continuous vacancy loading

Demkowicz

2015

J Mater Sci

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“…However, the atomic level details of how dislocation nucleation occurs at the grain boundary and what is the correlation of GB structures, GB properties, and the deformation mechanisms of GBs are still not understood very well. Moreover, a characterization of 900 GBs in pure annealed Ni performed by Randle 25 showed that over half of the interfaces consisted of <1 1 0> tilt GBs; this indicated that the <1 1 0> tilt GBs are a preferred interface configuration and of importance for face-centered cubic (fcc) materials. We therefore concentrated on the dislocation nucleation from <1 1 0> tilt GBs in this study and investigated their underlying atomistic mechanisms.…”

Section: Introductionmentioning

confidence: 99%

Molecular dynamics study on the grain boundary dislocation source in nanocrystalline copper under tensile loading

Zhang

Lü

Pei

et al. 2015

Mater. Res. Express

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Grain boundary (GB) is the interface between different oriented crystals of the same material, and it can have a significant effect on the many properties of materials. When the average or entire range of grain size is reduced to less than 100 nm, the conventional plastic deformation mechanisms dominated by dislocation processes become difficult and GBmediated deformation mechanisms become increasingly important. One of the mechanisms that can play a profound role in the strength and plasticity of metallic polycrystalline materials is the heterogeneous nucleation and emission of dislocations from GB. In this study, we conducted molecular dynamics simulations to study the dislocation nucleation from copper bicrystal with a number of 〈1 10〉 tilt GBs that covered a wide range of misorientation angles (θ).Wewill show from this analysis that the mechanic behavior of GBs and the energy barrier of dislocation nucleation from GBs are closely related to the lattice crystallographic orientation, GBenergy, and the intrinsic GBstructures. An atomistic analysis of the nucleation mechanisms provided details of this nucleation and emission process that can help us to better understand the dislocation source in GB. Abstract: Grain boundary (GB) is the interface between different oriented crystals of the same material, and it can have a significant effect on the many properties of materials. When the average or entire range of grain size is reduced to less than 100 nm, the conventional plastic deformation mechanisms dominated by dislocation processes become difficult and GB mediated deformation mechanisms become increasingly important. One of the mechanisms that can play a profound role in the strength and plasticity of metallic polycrystalline materials is the heterogeneous nucleation and emission of dislocations from GB. In this study, we conducted molecular dynamics simulations to study the dislocation nucleation from copper bicrystal with a number of <1 1 0> tilt GBs that covered a wide range of misorientation angles (θ). We will show from this analysis that the mechanic behavior of GBs and the energy barrier of dislocation nucleation from GBs are closely related to the lattice crystallographic orientation, GB energy, and the intrinsic GB structures. An atomistic analysis of the nucleation mechanisms provided details of this nucleation and emission process that can help us to better understand the dislocation source in GB.

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“…1) Several researchers have studied the electrical properties of the frequently observed AE3 n GB series and reported that low AE GBs, especially (111) AE3 GB, show lower electrical activity than high AE and random GBs. [2][3][4] These trends are most likely connected with the GB energy due to the fact that the experimentally measured carrier recombination velocity shows similar trend with the theoretically calculated GB energy.…”

Section: Introductionmentioning

confidence: 99%

Modification of Local Structure and Its Influence on Electrical Activity of Near (310) Σ5 Grain Boundary in Bulk Silicon

et al. 2007

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We report on the modification of the local structures of (310) AE5 grain boundary in bulk silicon as the growth of crystal and its influence on electrical activity. The grain boundary was formed via floating-zone growth method utilizing bicrystal seed. The misalignment of the seed resulted in formation of the grain boundary with small deviations of crystal orientation from the AE5 singular coincidence orientation. The deviations consist of tilt and twist components and they were found to monotonically decrease with respect to the distance from the seed crystal accompanied by the decrease in density of dislocations on the grain boundary. The change in the grain boundary structure allows a systematic study on the correlation between the structure and the electrical activity at the GB. The density of dislocations was found to control the electrical activity and the (310) AE5 coincidence grain boundary without any dislocations is expected to show a very low electrical activity.

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Overview No. 127The role of the grain boundary plane in cubic polycrystals

Cited by 135 publications

References 72 publications

Non-coherent Cu grain boundaries driven by continuous vacancy loading

Non-coherent Cu grain boundaries driven by continuous vacancy loading

Molecular dynamics study on the grain boundary dislocation source in nanocrystalline copper under tensile loading

Modification of Local Structure and Its Influence on Electrical Activity of Near (310) Σ5 Grain Boundary in Bulk Silicon

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Overview No. 127The role of the grain boundary plane in cubic polycrystals

Cited by 135 publications

References 72 publications

Non-coherent Cu grain boundaries driven by continuous vacancy loading

Non-coherent Cu grain boundaries driven by continuous vacancy loading

Molecular dynamics study on the grain boundary dislocation source in nanocrystalline copper under tensile loading

Modification of Local Structure and Its Influence on Electrical Activity of Near (310) &Sigma;5 Grain Boundary in Bulk Silicon

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Modification of Local Structure and Its Influence on Electrical Activity of Near (310) Σ5 Grain Boundary in Bulk Silicon