Supersonic Dislocation Kinetics from an Augmented Peierls Model

Rosakis, Phoebus

doi:10.1103/physrevlett.86.95

Cited by 65 publications

(107 citation statements)

References 13 publications

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“…This implies that if the harmonic horizontal bonds are sufficiently strong, the island nucleation takes place only in the supersonic regime, and the steady supersonic propagation of the step becomes possible at V < V H . This is interesting in view of the close connection with dislocation motion and the recent discussions about whether a dislocation can move supersonically (Gumbsch and Gao, 1999;Rosakis, 2001). Note that the screw dislocation model considered in Ishioka (1971) and Celli and Flytzanis (1970) precludes this possibility, as does the Frenkel-Kontorova model studied in Weiner (1973, 1974), where breakdown of the steady dislocation motion at V /c ≈ 0.94 (0.95 is predicted by Flytzanis et al (1974)).…”

Section: Sequential Motion Of Three Stepsmentioning

confidence: 78%

Dynamics of steps along a martensitic phase boundary I: Semi-analytical solution

Zhen

Vainchtein

2008

Journal of the Mechanics and Physics of Solids

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We study the motion of steps along a martensitic phase boundary in a cubic lattice. To enable analytical calculations, we assume antiplane shear deformation and consider a phase transforming material with a stress-strain law that is piecewise linear with respect to one component of shear strain and linear with respect to another. Under these assumptions we derive a semi-analytical solution describing a steady sequential motion of the steps under an external loading. Our analysis yields kinetic relations between the driving force, the velocity of the steps and other characteristic parameters of the motion. These are studied in detail for the two-step and three-step configurations. We show that the kinetic relations are significantly affected by the material anisotropy. Our results indicate the existence of multiple solutions exhibiting sequential step motion.

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Section: Sequential Motion Of Three Stepsmentioning

confidence: 78%

Dynamics of steps along a martensitic phase boundary I: Semi-analytical solution

Zhen

Vainchtein

2008

Journal of the Mechanics and Physics of Solids

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“…15 The above shows that Eq. (39a) stands as a leading-order approximation to the fully dynamic extension of this model.…”

Section: Steady Motionmentioning

confidence: 82%

“…Also, alleviating the absence of steady supersonic steady states at stresses lower than σ th in the model would probably require enriching the model with lattice dispersion effects. 6,15,68 This is challenging bacause the collective-variable approach relies on the existence of explicit and reasonably easy-to-handle steady-state solutions. However, it should be noted that, due to the instability of straight dislocation lines at high velocities, 28 endowing the model with steady supersonic states might not be much relevant to 'real' (i.e.…”

Section: Concluding Discussionmentioning

confidence: 99%

“…Its real part turns out to be the previously obtained incomplete EoM, 24 while the imaginary part provides the missing equation for the core width. By construction, the obtained EoM will be seen to reduce in the steady-state limit to Rosakis's Model I, 15 which describes high-velocity steady motion in the nonsupersonic range. As a byproduct, we retrieve the kinetic relations of the latter model in a generic form, independent of the dislocation character.…”

Section: Introductionmentioning

confidence: 99%

“…10 So far, discussion of the transonic/subsonic transition has mainly been based either on the atomistic simulations, or on steady-state models. [13][14][15] It is natural, however, to expect that more complete understanding of the phenomenon will arise from a suitable dynamic equation of motion (EoM) of dislocations-yet to be found.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Equation of motion and subsonic-transonic transitions of rectilinear edge dislocations: A collective-variable approach

Pellegrini

2014

Phys. Rev. B

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A theoretical framework is proposed to derive a dynamic equation motion for rectilinear dislocations within isotropic continuum elastodynamics. The theory relies on a recent dynamic extension of the Peierls-Nabarro equation, so as to account for core-width generalized stacking-fault energy effects. The degrees of freedom of the solution of the latter equation are reduced by means of the collective-variable method, well-known in soliton theory, which we reformulate in a way suitable to the problem at hand. Through these means, two coupled governing equations for the dislocation position and core width are obtained, which are combined into one single complex-valued equation of motion, of compact form. The latter equation embodies the history dependence of dislocation inertia. It is employed to investigate the motion of an edge dislocation under uniform time-dependent loading, with focus on the subsonic/transonic transition. Except in the steady-state supersonic range of velocities-which the equation does not address-our results are in good agreement with atomistic simulations on tungsten. In particular, we provide an explanation for the transition, showing that it is governed by a loading-dependent dynamic critical stress. The transition has the character of a delayed bifurcation. Moreover, various quantitative predictions are made, that could be tested in atomistic simulations. Overall, this work demonstrates the crucial role played by core-width variations in dynamic dislocation motion.

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Ultrafast Switching in Avalanche‐Driven Ferroelectrics by Supersonic Kink Movements

Salje

Wang

Ding

et al. 2017

Adv Funct Materials

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Devices operating at GHz frequencies can be based on ferroelectric kinkdomains moving at supersonic speed. The kinks are located inside ferro elastic twin boundaries and are extremely mobile. Computer simulation shows that strong forcing generates velocities well above the speed of sound. Kinks are accelerated from v = 0 continuously with Döring masses in the order of skyrmion masses under constant strain rates. Moving kinks emit phonons at all velocities, and the emission cones coincide with the Mach cones at supersonic speed. Kinks form avalanches with the emission of secondary kinks via a mother-daughter nucleation mechanism and may be observable in acoustic emission experiments. Supersonic kinks define a new type of material; while mobile domains are the key for ferroelastic and ferroelectric device applications at low frequencies, it is expected that fast kink movements replace such domain movements for materials applications at high frequencies.

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Supersonic Dislocation Kinetics from an Augmented Peierls Model

Cited by 65 publications

References 13 publications

Dynamics of steps along a martensitic phase boundary I: Semi-analytical solution

Dynamics of steps along a martensitic phase boundary I: Semi-analytical solution

Equation of motion and subsonic-transonic transitions of rectilinear edge dislocations: A collective-variable approach

Ultrafast Switching in Avalanche‐Driven Ferroelectrics by Supersonic Kink Movements

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