Journal ArticleDOI
The Orowan mechanism in anisotropic crystals
R.O. Scattergood,David Bacon +1 more
TLDR
The static equilibrium configurations of a dislocation bypassing a periodic row of impenetrable circular obstacles were obtained for various crystals by means of a self-stress method wherein the elastic anisotropy of the crystal and the dislocation self-interaction could be taken into account.Abstract:
The static equilibrium configurations of a dislocation bypassing a periodic row of impenetrable circular obstacles were obtained for various crystals by means of a self-stress method wherein the elastic anisotropy of the crystal and the dislocation self-interaction could be taken into account. A correlation was developed from the results which related the Orowan stress values to the obstacle size and spacing. This correlation demands two parameters to account for the anisotropy, and these appear as a suitably defined anisotropic shear modulus and Poisson's ratio. The self-interactions are taken into account by a single logarithmic parameter which is the harmonic mean of the obstacle size and spacing, and is independent of anisotropy. The shapes of the bowing dislocation loops are strongly influenced by the anisotropy and interactions. The combined effects on shape can bo simply described in the line-tension framework, using the de Wit—Koehler solutions. In particular, the swept areas and overall ...read more
Citations
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Journal ArticleDOI
Atomic-Scale Mechanisms of Void Hardening in BCC and FCC Metals
Yu.N. Osetsky,David Bacon +1 more
TL;DR: In this article, an atomic-scale modeling to compare edge dislocation-void interaction in fcc copper and bcc iron was presented. But the results were limited to the case of small voids.
Journal ArticleDOI
Interaction of an edge dislocation with voids in α-iron modelled with different interatomic potentials
TL;DR: Ackland et al. as mentioned in this paper investigated the effect of the dislocation segment in the 70°-mixed orientation with the interatomic potential on the critical line shape at which the dislocations breaks from the void and found that the effect on the line shape does not arise from anisotropy of the elastic line tension.
Simulation of the interaction between an edge dislocation and a '100' interstitial dislocation loop in alpha-iron
TL;DR: In this paper, the interaction of an edge dislocation with interstitial dislocation loops in α-iron at 300 K was studied systematically for different loop positions and Burgers vector orientations, and results were compared for two different interatomic potentials.
Journal ArticleDOI
Characterization of thermodynamic response by materials testing
Journal ArticleDOI
Level set simulations of dislocation-particle bypass mechanisms
TL;DR: In this paper, the authors present the results of full 3D dislocation dynamics simulations, based on the level set method, that naturally accounts for all of the complexities associated with elastic interactions between dislocation segments, their interactions with particle stress field, the flexibility of the dislocation line in three dimensions and the threedimensional topological changes that occur.
References
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Book
Theory of Dislocations
John Price Hirth,Jens Lothe +1 more
TL;DR: Dislocations in Isotropic Continua: Effects of Crystal Structure on Dislocations and Dislocation-Point-Defect Interactions at Finite temperatures.
Journal ArticleDOI
The effect of dislocation self-interaction on the Orowan stress
TL;DR: In this article, the effect of dislocation self-interaction on the Orowan stress was determined for collinear, impenetrable circular obstacles, and an appropriate integro-differential equation governing static equilibrium was solved by an algorithm based on curvature adjustments.
Journal ArticleDOI
The self-stress of dislocations and the shape of extended nodes
TL;DR: In this article, a definition of the self-stress of a dislocation is proposed which is closely related to the more usual notion of a line tension, enabling a numerical calculation to be made of the shape of extended nodes in dislocation networks, and such a calculation leads to revised values of stacking-fault energies of alloys.
Journal ArticleDOI
Interaction of Dislocations with an Applied Stress in Anisotropic Crystals
G. deWit,J. S. Koehler +1 more
TL;DR: In this article, the equilibrium shape of a dislocation segment between two pinning points in the same glide plane is calculated using an energy per unit length, which is a function only of the angle between the Burgers vector and the tangent to the dislocation.