We have employed the semidiscrete variational generalized Peierls-Nabarro model to study the dislocation core properties of aluminum. The generalized stacking fault energy surfaces entering the model are calculated by using first-principles Density Functional Theory (DFT) with pseudopotentials and the embedded atom method (EAM). Various core properties, including the core width, splitting behav...

We give a bird’s-eye view of the plastic deformation of crystals aimed at the statistical physics community, and a broad introduction into the statistical theories of forced rigid systems aimed at the plasticity community. Memory effects in magnets, spin glasses, charge density waves, and dilute colloidal suspensions are discussed in relation to the onset of plastic yielding in crystals. Disloc...

Al-Mg-Cu-Mn alloys have been developed for the packaging industry, in which large cold-working deformations are normally applied that can produce high dislocation densities. In this study, we present a simplified model for the yield strength contributions and apply that to obtain the dislocation densities by determining the orientation factors, which can be obtained via the crystal information ...

Predicting atomistic properties of a dislocation is a first step toward an understanding of plastic behavior of materials, in particular BCC metals. The core structure and Peierls stress of a screw dislocation in BCC metals have been studied over the years using the first-principles and empirical methods, however, their conclusions vary due to the inefficiency of the methods. We have executed f...

In this paper we analyse the behaviour of a pile-up of vertically periodic walls of edge dislocations at an obstacle, represented by a locked dislocation wall. Starting from a continuum non-local energy Ec modelling the interactions—at a typical length scale of 1/c— of the walls subjected to a constant shear stress, we derive a first-order approximation of the energy by Γ-convergence in the lim...

The objective of the paper is modeling of material softening after the deformation. The main problem of almost every model with digital material representation is consideration of recrystallization as the only mechanism of material softening. Static recovery is introduced into the model based on frontal cellular automata. An influence of static recovery on softening process is twofold. Static r...

condylar dislocation is not an uncommon condition and occurs when the condyles are displaced anterior to the articular eminence and are unable to reduce back into the glenoid fossa. long-standing dislocations are difficult to treat with the conservative methods and usually need surgical intervention. in this paper, a long-standing dislocation treated by bilateral extra-oral ramus osteotomy is d...

The physical basis of computationally tractable models of crystalline plasticity is reviewed. A statistical mechanical model of dislocation motion through forest dislocations is formulated. Following Franciosi and co-workers, the strength of the short-range obstacles introduced by the forest dislocations is allowed to depend of the mode of interaction. The kinetic equations governing dislocatio...

We focus on mesoscopic dislocation patterning via a continu um dislocation dynamics theory (CDD) in three dimensions (3D). We study three distinct physically motivated dynamics which consistently lead to fractal formation in 3D with rather similar morphologies, and therefore we suggest that this is a general feature of the 3D collective behavior of geometrically necessar y dislocation (GND) ens...

A TEM study of pure tantalum and tantalum-tungsten alloys explosively shocked at a peak pressure of 30 GPa is presented. While no omega phase was found in shock-recovered pure Ta and Ta-5W which mainly contain a cellular dislocation structure, a shock-induced omega phase was found in Ta-10W which contains evenly distributed dislocations with a density higher than 1 × 10(12) cm( - 2). The shock-...