Thermally-activated non-Schmid glide of screw dislocations in W using atomistically-informed kinetic Monte Carlo simulations

@article{Stukowski2014ThermallyactivatedNG,
  title={Thermally-activated non-Schmid glide of screw dislocations in W using atomistically-informed kinetic Monte Carlo simulations},
  author={Alexander Stukowski and David Cereceda and Thomas D. Swinburne and Jaime Marian},
  journal={International Journal of Plasticity},
  year={2014},
  volume={65},
  pages={108-130}
}
Thermally-activated 1=2h111i screw dislocation motion is the controlling plastic mechanism at low temperatures in body-centered cubic (bcc) crystals. Dislocation motion proceeds by nucleation and propagation of atomic-sized kink pairs in close-packed planes. The atomistic character of kink pairs can be studied using techniques such as molecular dynamics (MD). However, MD’s natural inability to properly sample thermally-activated processes as well as to capture f110g screw dislocation glide… 
Temperature and Stress Dependence of Screw Dislocation Mobility in Nb-V-Ta Alloys Using Kinetic Monte Carlo Simulations
In this work we present simulations of thermally-activated screw dislocation motion in Nb-Ta-V alloys for two distinct scenarios, one where kink propagation is solely driven by chemical energy
Linking atomistic, kinetic Monte Carlo and crystal plasticity simulations of single-crystal tungsten strength
© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Understanding and improving the mechanical properties of tungsten is a critical task for the materials fusion energy program. The plastic behavior
Two-scale simulation of plasticity in molybdenum: Combination of atomistic simulation and dislocation dynamics with non-linear mobility function
Abstract We present multi-scale simulation of plastic deformation in molybdenum. The temperature-dependent mobility functions of screw and edge dislocations were calculated from molecular dynamics
Coupling 2D atomistic information to 3D kink-pair enthalpy models of screw dislocations in bcc metals
The kink-pair activation enthalpy is a fundamental parameter in the theory of plasticity of body-centered cubic (bcc) metals. It controls the thermally activated motion of screw dislocation at low
Quantifying the dynamics of dislocation kinks in iron and tungsten through atomistic simulations
Abstract When high-Peierls-barrier materials such as iron (Fe) and tungsten (W) are deformed, dislocation kinks can be easily activated. The subsequent kink dynamics may dictate the dislocation
An atomistically informed kinetic Monte Carlo model for predicting solid solution strengthening of body-centered cubic alloys
Abstract In order to predict solid solution strengthening in body-centered cubic dilute substitutional alloys, we developed an atomistically informed kinetic Monte Carlo (kMC) model for screw
Direct prediction of the solute softening-to-hardening transition in W-Re alloys using stochastic simulations of screw dislocation motion
Interactions among dislocations and solute atoms are the basis of several important processes in metals plasticity. In body-centered cubic (bcc) metals and alloys, low-temperature plastic flow is
Screw dislocations in BCC transition metals: from ab initio modeling to yield criterion
We show here how density functional theory calculations can be used to predict the temperatureand orientation-dependence of the yield stress of body-centered cubic (BCC) metals in the
Atomistic simulations of dislocation mobility in refractory high-entropy alloys and the effect of chemical short-range order
TLDR
Mechanisms underlying the mobilities of screw and edge dislocations in the body-centered cubic MoNbTaW RHEA over a wide temperature range are investigated using extensive molecular dynamics simulations based on a highly-accurate machine-learning interatomic potential.
Temperature insensitivity of the flow stress in body-centered cubic micropillar crystals
Abstract Plasticity of body-centered cubic (bcc) crystals is known to have a strong dependence on temperature, as a direct consequence of the thermally-activated process of kink pair nucleation and
...
1
2
3
4
5
...

References

SHOWING 1-10 OF 74 REFERENCES
Crystal plasticity model for BCC iron atomistically informed by kinetics of correlated kinkpair nucleation on screw dislocation
Abstract The mobility of dislocation in body-centered cubic (BCC) metals is controlled by the thermally activated nucleation of kinks along the dislocation core. By employing a recent interatomic
Assessment of interatomic potentials for atomistic analysis of static and dynamic properties of screw dislocations in W.
TLDR
It is concluded that a modified embedded-atom potential achieves the best compromise in terms of static and dynamic screw dislocation properties, although at an expense of about ten-fold compared to central potentials.
Theory and simulation of the diffusion of kinks on dislocations in bcc metals
Isolated kinks on thermally fluctuating (1/2) screw, edge and (1/2) edge dislocations in bcc iron are simulated under zero stress conditions using molecular dynamics (MD). Kinks are seen to perform
The glide of screw dislocations in bcc Fe: Atomistic static and dynamic simulations ☆
We present atomic-scale simulations of screw dislocation glide in bcc iron. Using two interatomic potentials that, respectively, predict degenerate and non-degenerate core structures, we compute the
Stress and temperature dependence of screw dislocation mobility in α -Fe by molecular dynamics
The low-temperature plastic yield of α-Fe single crystals is known to display a strong temperature dependence and to be controlled by the thermally activated motion of screw dislocations. In this
An atomistically-informed dislocation dynamics model for the plastic anisotropy and tension–compression asymmetry of BCC metals
Abstract Atomistic simulations have shown that a screw dislocation in body-centered cubic (BCC) metals has a complex non-planar atomic core structure. The configuration of this core controls their
Linewise kinetic Monte Carlo study of silicon dislocation dynamics
We present a number of n-fold way kinetic Monte Carlo simulations of the glide motion of 90° partial dislocations in silicon. We undertake a survey of ratios of kink formation energy F k to kink
Ab-initio simulation of isolated screw dislocations in bcc Mo and Ta
Abstract The equilibrium core structure of isolated (a/2)⟨111⟩ screw dislocations are calculated using a first-principles pseudopotential plane-wave method within the local-density approximation of
Atomistic simulation of single kinks of screw dislocations in α-Fe
Abstract We have studied the structure and the formation and migration energies of single kinks in ½〈1 1 1〉 screw dislocations in body-centered cubic iron, by performing static calculations using the
Kinetic Monte Carlo modeling of dislocation motion in BCC metals
Abstract We present a kinetic Monte Carlo (kMC) simulation method for modeling screw dislocation motion in BCC metals on the micron–second scales, using inputs from atomistic simulations of core
...
1
2
3
4
5
...