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Related papers: Strain rate dependency of dislocation plasticity

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This paper presents experimental evidence and theoretical models supporting that dry friction stick-slip is described by self-organized criticality. We use the data, obtained with a pin-on-disc tribometer set to measure lateral force to…

Materials Science · Physics 2009-11-11 Sergey V. Buldyrev , John Ferrante , Fredy R. Zypman

The dislocation structures appearing in highly mis-oriented soft/hard grain pairs in near-alpha titanium alloy Ti6242Si were examined with and without the application of load holds (dwell) during fatigue. Dislocation pile-up in a soft grain…

Materials Science · Physics 2020-05-14 Sudha Joseph , Kavitha Joseph , Trevor C Lindley , David Dye

Metallic materials under high stress often exhibit deformation localization, manifesting as slip banding. Over seven decades ago, Frank and Read introduced the well-known model of dislocation multiplication at a source, explaining slip band…

Owing to their non-planar cores 1/2<111> screw dislocations govern the plastic deformation of BCC metals. Atomistic studies of the glide of these dislocations at 0 K have been performed using Bond Order Potentials for molybdenum and…

Materials Science · Physics 2008-07-18 R. Gröger , A. G. Bailey , V. Vitek

In recent years there has been renewed interest in the behavior of dislocations in crystals that exhibit strong atomic scale disorder, as typical of compositionally complex single phase alloys. The behavior of dislocations in such crystals…

Materials Science · Physics 2021-10-26 Aviral Vaid , De'an Wei , Erik Bitzek , Samaneh Nasiri , Michael Zaiser

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

Dislocation nucleation is essential to our understanding of plastic deformation, ductility and mechanical strength of crystalline materials. Molecular dynamics simulation has played an important role in uncovering the fundamental mechanisms…

Materials Science · Physics 2015-05-20 Seunghwa Ryu , Keonwook Kang , Wei Cai

The existence of a well defined yield stress, where a macroscopic piece of crystal begins to plastically flow, has been one of the basic observations of materials science. In contrast to macroscopic samples, in micro- and nanocrystals the…

There is growing interest in promoting deformation twinning for plasticity in advanced materials, as highly organized twin boundaries are beneficial to better strength-ductility combination in contrast to disordered grain boundaries.…

Materials Science · Physics 2016-04-05 Peng Wang , Shaofeng Xu , Jiabin Liu , Xiaoyan Li , Yujie Wei , Hongtao Wang , Huajian Gao , Wei Yang

The lifetime of moving metallic components is often limited by accelerated oxidation. Yet, the mechanisms and pathways for oxidation during tribological loading are not well understood. Using copper as a model system, tribologically-induced…

Strain-based theory on elastic instabilities is being widely employed for studying onset of plasticity, phase transition or melting in crystals. And size effects, observed in nano-materials or solids under dynamic loadings, needs to account…

Materials Science · Physics 2017-07-20 Kun Wang , Jun Chen , Wenjun Zhu , Meizhen Xiang

Molecular dynamics simulations are performed to investigate the role of a coherent {\Sigma}3 (111) twin boundary on the plastic deformation behavior of Cu nanopillars. Our work reveals that the mechanical response of pillars with and…

The validity of the structure-property relationships governing the deformation behavior of bcc metals was brought into question with recent {\it ab initio} density functional studies of isolated screw dislocations in Mo and Ta. These…

Materials Science · Physics 2008-08-22 Travis E. Jones , Mark E. Eberhart , Dennis P. Clougherty , Chris Woodward

We report two-dimensional discrete dislocation dynamics simulations of combined dislocation glide and climb leading to `power-law' creep in a model aluminum crystal. The approach fully accounts for matter transport due to vacancy diffusion…

Mesoscale and Nanoscale Physics · Physics 2017-12-27 Shyam M. Keralavarma , Tahir Cagin , Tom Arsenlis , A. Amine Benzerga

In this paper we present a simple and effective numerical method which allows a fast Fourier transformation-based evaluation of stress generated by dislocations with arbitrary directions and Burgers vectors if the (site-dependent)…

Materials Science · Physics 2018-04-06 D. V. Berkov , N. L. Gorn

A physically-informed continuum crystal plasticity model is presented to elucidate the deformation mechanisms and dislocation evolution in body-centered-cubic (bcc) tantalum widely used as a key structural material for mechanical and…

The effect of interstitial hydrogen on the elastic properties of $\alpha$-iron is investigated using \textit{ab initio} density functional theory. We find that while the overall strength properties are reduced by H, the effects are mainly…

Materials Science · Physics 2012-09-14 D. Psiachos , T. Hammerschmidt , R. Drautz

We investigate dynamic fracture of heterogeneous materials experimentally by measuring displacement fields as a rupture propagates through a periodic array of obstacles of controlled fracture energy. Our measurements demonstrate the…

Soft Condensed Matter · Physics 2021-07-21 Gabriele Albertini , Mathias Lebihain , François Hild , Laurent Ponson , David S. Kammer

Crystal plasticity is mediated through dislocations, which form knotted configurations in a complex energy landscape. Once they disentangle and move, they may also be impeded by permanent obstacles with finite energy barriers or frustrating…

Materials Science · Physics 2018-01-17 Stefanos Papanikolaou , Yinan Cui , Nasr Ghoniem

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