Grain-boundary kinetics: A unified approach

Han, Jian; Thomas, Spencer L.; Srolovitz, David J.

doi:10.1016/j.pmatsci.2018.05.004

Cited by 326 publications

(210 citation statements)

References 377 publications

(707 reference statements)

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“…where a is an atomic spacing, k B is the Boltzmann constant, T is temperature and E * i is half of the formation energy of a disconnection pair (Han et al, 2018). We assume that disconnection nucleation is sufficiently facile that the nucleation rate is determined by thermal equilibrium considerations (this may not be universally valid).…”

Section: Grain Boundary Motion With Multiple Disconnection Modesmentioning

confidence: 99%

“…Disconnections are constrained to lie within the GB and are characterized by both a Burgers vector b and a step height H. The motion of disconnections along the GB leads to both GB migration (associated with the step height) and shear coupling (associated with the Burgers vectors) (Thomas et al, 2017;Han et al, 2018). Recently, a continuum model for GB migration was proposed based upon the motion of a single type of disconnection (Zhang et al, 2017).…”

Section: Introductionmentioning

confidence: 99%

“…However, bicrystallography allows for an infinite, discrete set of possible disconnection types or modes (King and Smith, 1980;Han et al, 2018). A disconnection mode is associated with a Burgers vector and step height pair {b n , H nj }; for each Burgers vector b n there are an infinite set of possible step heights {H nj }.…”

Section: Introductionmentioning

confidence: 99%

“…A disconnection mode is associated with a Burgers vector and step height pair {b n , H nj }; for each Burgers vector b n there are an infinite set of possible step heights {H nj }. The selection of and competition between disconnection modes are central to understanding the temperature-dependence of GB shear coupling, mobility, and sliding (Thomas et al, 2017;Han et al, 2018;Chen et al, 2019). Such competition varies between GBs and even along a GB within a microstructure, resulting in complex/rich GB migration phenomenon in polycrystalline microstructures.…”

Section: Introductionmentioning

confidence: 99%

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A Continuum Multi-Disconnection-Mode model for grain boundary migration

Wei¹,

Thomas²,

Han³

et al. 2019

Journal of the Mechanics and Physics of Solids

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We study the Grain Boundary (GB) migration based on the underlying disconnection structure and mechanism. Disconnections are line defects that lie solely within a GB and are characterized by both a Burgers vector and a step height, as set by the GB bicrystallography. Multiple disconnection modes can nucleate, as determined by their formation energy barriers and temperature, and move along the GB under different kinds of competing driving forces including shear stress and chemical potential jumps across the GBs. We present a continuum model in two dimensions for GB migration where the GB migrates via the thermally-activated nucleation and kinetically-driven motion of disconnections. We perform continuum numerical simulations for investigating the GB migration behavior in single and multi-mode disconnection limits in both a bicrystal (under two types of boundary conditions) and for a finite-length GB with pinned ends. The results clearly demonstrate the significance of including the coupling and competing between different disconnection modes and driving forces for describing the complex and diverse phenomena of GB migration within polycyrstalline microstructures.

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Section: Grain Boundary Motion With Multiple Disconnection Modesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

A Continuum Multi-Disconnection-Mode model for grain boundary migration

Wei¹,

Thomas²,

Han³

et al. 2019

Journal of the Mechanics and Physics of Solids

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“…The coupling factor is not unique to a given GB. It can change with temperature, direction of the shear stress and other factors as discussed in more detail in the recent literature [20]. It can also vary in time as the grain boundary structure changes due to the absorption or emission of vacancies [21].…”

Section: A General Equations For a Planar Grain Boundarymentioning

confidence: 99%

Effect of vacancy creation and annihilation on grain boundary motion

McFadden

Boettinger

2020

Acta Materialia

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Interaction of vacancies with grain boundaries (GBs) is involved in many processes occurring in materials, including radiation damage healing, diffusional creep, and solid-state sintering. We analyze a model describing a set of processes occurring at a GB in the presence of a non-equilibrium, non-homogeneous vacancy concentration. Such processes include vacancy diffusion toward, away from, and across the GB, vacancy generation and absorption at the GB, and GB migration. Numerical calculations within this model reveal that the coupling among the different processes gives rise to interesting phenomena, such as vacancy-driven GB motion and accelerated vacancy generation/absorption due to GB motion. The key combinations of the model parameters that control the kinetic regimes of the vacancy-GB interactions are identified via a linear stability analysis. Possible applications and extensions of the model are discussed.

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On the Migration of a High‐Angle Grain Boundary—Effect of Shear Stress and Energy Jump‐Driving Force on Micro‐Bicrystals

Velayarce,

Chen,

Berbenni

et al. 2024

Adv Eng Mater

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Grain boundary (GB) migration plays a crucial role in the microstructural evolution of polycrystalline materials, particularly in fine‐grained materials. This migration can be driven by shear forces or by an energy jump across a GB. Interestingly, GB migration processes during cyclic loading deformations have been observed to be fully reversible. In this study, we focus on understanding the impact and importance of shear driving forces, the free energy difference across a GB and lattice dislocations on GB migration. These factors are key points for gaining deeper insights into the underlying mechanisms of GB migration. In our work, we demonstrate GB migration in cyclic loading deformations and emphasize that it clearly depends on both the shear driving forces (attributed to the motion of disconnections) and the energy differential across the GB. Two cyclic micro‐experimental methods, accompanied by analytical and numerical simulations, have been employed to investigate the role of shear stresses and energy jump‐driving forces in grain boundary (GB) migration. Our investigation provides clear experimental evidence that GB migration, in particular for a high‐angle grain boundary (HAGB), is dependent on both stress and energy driving forces.This article is protected by copyright. All rights reserved.

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Grain-boundary kinetics: A unified approach

Cited by 326 publications

References 377 publications

A Continuum Multi-Disconnection-Mode model for grain boundary migration

A Continuum Multi-Disconnection-Mode model for grain boundary migration

Effect of vacancy creation and annihilation on grain boundary motion

On the Migration of a High‐Angle Grain Boundary—Effect of Shear Stress and Energy Jump‐Driving Force on Micro‐Bicrystals

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