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Related papers: Dislocation-mediated plasticity in the Al$_{2}$Cu …

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In this paper we consider the dynamics of dislocations with the same Burgers vector, contained in the same glide plane, and moving in a material with periodic obstacles. We study two cases: i) the particular case of parallel straight…

Analysis of PDEs · Mathematics 2015-05-13 A. El Hajj , H. Ibrahim , R. Monneau

Plastic deformation of crystals is a physical phenomenon, which has immensely driven the development of human civilisation since the onset of the Chalcolithic period. This process is primarily governed by the motion of line defects, called…

Materials Science · Physics 2009-07-15 A. Dutta , M. Bhattacharya , P. Mukherjee , N. Gayathri , G. C. Das , P. Barat

Matallic alloys, such as Al or Cu, or mild steel, display plastic instabilities in a well defined range of temperatures and deformation rates, a phenomenon known as the Portevin-Le Chatelelier (PLC) effect. The stick-slip behavior, or…

Materials Science · Physics 2014-02-12 Fabio Leoni , Stefano Zapperi

The continuous miniaturization of modern electromechanical systems calls for a comprehensive understanding of the mechanical properties of metallic materials specific to micrometer and sub-micrometer scales. At these scales, the nature of…

Materials Science · Physics 2019-07-26 Peng Zhang , Jian-Jun Bian , Chong Yang , Jin-Yu Zhang , Gang Liu , Jérôme Weiss , Jun Sun

In this work, molecular dynamics (MD) simulations were used to investigate elementary dislocation properties in a Co-free high entropy (HEA) model alloy ($Cr_{15}Fe_{46}Mn_{17}Ni_{22}$ at. %) in comparison with a model alloy representative…

Atomic and Molecular Clusters · Physics 2022-05-19 Ayobami Daramola , Anna Fraczkiewicz , Giovanni Bonny , Akiyoshi Nomoto , Gilles Adjanor , Christophe Domain , Ghiath Monnet

The cross-slip process of a screw $<$a$>$ dislocation from the basal to the prismatic plane in magnesium was studied using the density functional theory and the molecular dynamics calculations. An atomistic method for calculating the total…

Materials Science · Physics 2015-06-12 M. Itakura , H. Kaburaki , M. Yamaguchi , T. Tsuru

During plastic deformation, metals change shape while continuously becoming stronger. The microscopic origin of these processes lies in the proliferation and movement of line defects, dislocations, and the subsequent self-organisation and…

In this paper, the second part of a survey of the geometric properties of defects in quasicrystals studied from the Volterra viewpoint (see ref. [1]), we show that: 1$- $ a {\sf disvection line} L$_{||} \subset \mathrm E_{||}$ of Burgers…

Materials Science · Physics 2013-08-27 Maurice Kleman

The mechanical behaviour of Mg-Al alloys can be largely improved by the formation of an intermetallic Laves phase skeleton, in particular the creep strength. Recent nanomechanical studies revealed plasticity by dislocation glide in the…

We present a time-dependent Ginzburg-Landau model of nonlinear elasticity in solid materials. We assume that the elastic energy density is a periodic function of the shear and tetragonal strains owing to the underlying lattice structure.…

Statistical Mechanics · Physics 2009-11-10 Akira Onuki , Akira Furukawa , Akihiko Minam

The effect of slip transfer on the deformation mechanisms of Al bicrystals was explored using a rate-dependent dislocation-based crystal plasticity model. Three different types of grain boundaries (GBs) were included in the model by…

Materials Science · Physics 2020-01-27 S. Haouala , R. Alizadeh , T. R. Bieler , J. Segurado , J. LLorca

The classical motion of gliding dislocation lines in slip planes of crystalline solid helium leads to plastic deformation even at temperatures far below the Debye temperature and can affect elastic properties. In this work we argue that the…

\theta' (Al2Cu) precipitates in Al-Cu-Ag alloys were examined using high angle annular dark field scanning transmission electron microscopy (HAADF-STEM). The precipitates nucleated on dislocation loops on which assemblies of {\gamma}'…

Materials Science · Physics 2012-09-28 Julian M Rosalie , Laure Bourgeois

The viscoplastic deformation (creep) of crystalline materials under constant stress involves the motion of a large number of interacting dislocations. Analytical methods and sophisticated `dislocation-dynamics' simulations have proved very…

Statistical Mechanics · Physics 2009-11-07 M. -Carmen Miguel , Alessandro Vespignani , Stefano Zapperi , Jerome Weiss , Jean-Robert Grasso

Plasticity in body-centred cubic (BCC) metals, including dislocation interactions at grain boundaries, is much less understood than in face-centred cubic (FCC) metals. At low temperatures additional resistance to dislocation motion due to…

Materials Science · Physics 2020-06-11 Martin Heller , James S. K. -L. Gibson , Risheng Pei , Sandra Korte-Kerzel

The critical resolved shear stress of an Al 4 wt. \% Cu alloy containing a homogeneous distribution of $\theta''$ precipitates was determined by means of dislocation dynamics simulations. The size distribution, shape, orientation and volume…

Materials Science · Physics 2021-04-07 R. Santos-Güemes , L. Capolungo , J. Segurado , J. LLorca

Slip transmission across $\alpha-\beta$ interfaces is of great significance in understanding the strength of $\alpha-\beta$ Ti alloys for aerospace applications. Molecular statics (MS) and molecular dynamics (MD) simulations were conducted…

Materials Science · Physics 2023-09-15 Ali Rida , Satish I. Rao , Jaafar A. El-Awady

Slip intermittency and stress oscillations in titanium alloy Ti-7Al-O that were observed using in-situ far-field high energy X-ray diffraction microscopy (ff-HEDM) are investigated using a discrete dislocation plasticity (DDP) model. The…

Materials Science · Physics 2023-08-09 Yilun Xu , Felicity Worsnop , David Dye , Fionn P. E. Dunne

To understand how dislocations form ordered structures during the deformation of metals, we perform computer simulation studies of the dynamics and patterning of screw dislocations in two dimensions. The simulation is carried out using an…

Materials Science · Physics 2007-05-23 Robin L. B. Selinger , Brian B. Smith , Wei-Dong Luo

Using first principles methods we calculated the entire {\gamma}-surface of the first order pyramidal planes in {\alpha}-titanium. Slip on these planes involving dislocations with c + a dislocations is one means by which {\alpha}-titanium…

Materials Science · Physics 2016-10-04 Adam J. Ready , Adrian P. Sutton , Peter D. Haynes , David Rugg