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Related papers: Glide and Superclimb of Dislocations in Solid $^4$…

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We have considered the dislocation network model for the supersolid state in He-4 crystals. In difference with uniform 2D and 3D systems, the temperature of superfluid transition T_c in the network is much smaller than the degeneracy…

Quantum Gases · Physics 2015-05-13 D. V. Fil , S. I. Shevchenko

By direct application of stress in molecular statics calculations we identify the stress components that affect the glide of 1/2<111> screw dislocations in bcc tungsten. These results prove that the hydrostatic stress and the normal stress…

Materials Science · Physics 2015-06-17 R. Gröger

Analysis is given of the changes of dislocation motion modes with stress and temperature variation. Different regimes of dislocation kink pair formation and spreading (motion in the random potential, in the field of random forces, the…

Materials Science · Physics 2007-05-23 Yu. L. Iunin , V. I. Nikitenko

Thermally-activated $\small{\nicefrac{1}{2}}<111>$ screw dislocation motion is the controlling plastic mechanism at low temperatures in body-centered cubic (bcc) crystals. Motion proceeds by the nucleation and propagation of atomic-sized…

Materials Science · Physics 2014-08-27 Alexander Stukowski , David Cereceda , Thomas D. Swinburne , Jaime Marian

Several experiments show that crystalline solids deform in a bursty and intermittent fashion. Power-law distributed strain bursts in compression experiments of micron-sized samples, and acoustic emission energies from larger-scale…

Materials Science · Physics 2015-06-02 Markus Ovaska , Lasse Laurson , Mikko J. Alava

Dislocation model of the supersolid state of $^4$He was proposed in 1987 by one of the authors of the review. The model obtained strong support by numerous experimental and theoretical investigations from 2007 to date. In these…

Quantum Gases · Physics 2022-08-01 D. V. Fil , S. I. Shevchenko

The thermally activated motion of dislocations across fields of obstacles distributed at random and in a correlated manner, in separate models, is studied by means of computer simulations. The strain rate sensitivity and strength are…

Computational Physics · Physics 2018-07-27 Zhijie Xu , Catalin Picu

Plasticity in hexagonal close packed (HCP) metals and alloys such as Titanium (Ti) and Zirconium (Zr) is carried out by the motion of $\langle a \rangle$ dislocations. Above room temperature, in situ transmission electron microscopy…

Materials Science · Physics 2023-10-25 Ali Rida , Satish I. Rao , Jaafar A. El-Awady

Atomic-scale calculations for the dynamics of the 90$^0$ partial glide dislocation in silicon are made using the effective-medium tight-binding theory. Kink formation and migration energies for the reconstructed partial dislocation are…

Materials Science · Physics 2008-02-03 K. Stokbro , L. B. Hansen , B. I. Lundqvist

We study the dynamic response of a superfluid field to a moving edge dislocation line to which the field is minimally coupled. We use a dissipative Gross-Pitaevskii equation, and determine the initial conditions by solving the equilibrium…

Quantum Gases · Physics 2017-04-21 Abdul N. Malmi-Kakkada , Oriol T. Valls , Chandan Dasgupta

We employ the methods of atomistic simulation to investigate the climb of edge dislocation at nanovoids by analyzing the energetics of the underlying mechanism. A novel simulation strategy has been demonstrated to estimate the release of…

Materials Science · Physics 2013-04-22 A. Dutta , M. Bhattacharya , N. Gayathri , G. C. Das , P. Barat

Plasticity in hexagonal close-packed zirconium is controlled by screw dislocations which easily glide in the prismatic planes where they are dissociated. At high enough temperatures, these dislocations can deviate out of the prism planes to…

Materials Science · Physics 2021-12-09 Émile Maras , Emmanuel Clouet

The effects of dislocation climb on plastic deformation during loading and unloading are studied using a two-dimensional discrete dislocation dynamics model. Simulations are performed for polycrystalline thin films passivated on both…

Materials Science · Physics 2014-01-03 Kamyar M. Davoudi , Lucia Nicola , Joost J. Vlassak

A novel model based on the Peierls framework of dislocations is developed. The new theory can deal with a dislocation spreading at more than one slip planes. As an example, we study dislocation cross-slip and constriction process of two fcc…

Materials Science · Physics 2009-11-07 Gang Lu , Vasily V. Bulatov , Nicholas Kioussis

We investigate the depinning transition occurring in dislocation assemblies. In particular, we consider the cases of regularly spaced pileups and low angle grain boundaries interacting with a disordered stress landscape provided by solute…

Statistical Mechanics · Physics 2009-11-10 Paolo Moretti , M. -Carmen Miguel , Michael Zaiser , Stefano Zapperi

A model based on dislocation glide controlled by the nucleation and propagation of kink pairs in a high Peierls stress crystal is revisited and modified to account for changes in dislocation densities and segment lengths with temperature…

The interplay of screw dislocations with carbon atoms is investigated in tungsten at high temperature using in situ straining experiments in a transmission electron microscope (TEM) and through ab initio calculations. When the temperature…

Materials Science · Physics 2021-11-24 Guillaume Hachet , Daniel Caillard , Lisa Ventelon , Emmanuel Clouet

Crystalline materials deform in an intermittent way via dislocation-slip avalanches. Below a critical stress, the dislocations are jammed within their glide plane due to long-range elastic interactions and the material exhibits plastic…

Soft Condensed Matter · Physics 2015-05-20 Georgios Tsekenis , Nigel Goldenfeld , Karin A. Dahmen

Dislocation assemblies exhibit a jamming or yielding transition at a critical external shear stress value $\sigma=\sigma_c$. Nevertheless the nature of this transition has not been ascertained. Here we study the heterogeneous and collective…

Statistical Mechanics · Physics 2015-05-18 Lasse Laurson , M. -Carmen Miguel , Mikko J. Alava

We study a one-dimensional model of a dislocation pileup driven by an external stress and interacting with random quenched disorder, focusing on predictability of the plastic deformation process. Upon quasistatically ramping up the…

Materials Science · Physics 2020-12-21 Mika Sarvilahti , Audun Skaugen , Lasse Laurson