Discrete dislocation dynamics simulations of plasticity at small scales

Zhou, Caizhi; Biner, S.B.; LeSar, Richard

doi:10.1016/j.actamat.2009.11.001

Cited by 149 publications

(78 citation statements)

References 62 publications

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“…Значения n = 0.6−0.7, относятся к начальной стадии сжатия нанокристалла (деформациям 0.2−2%), а n = 0.9−1.0 -к стадии истощения деформационного упрочнения (деформаци-ям 10−30%). Компьютерное МД [6] и дискретно-дислокационное 3−D [7] моделирование пластической деформации кристаллов с субмикронными поперечны-ми размерами подтверждает существование размерных эффектов.…”

Section: Introductionunclassified

“…Особенностью пластической деформации нанокри-сталлов является наличие в их приповерхностном слое большой плотности однополюсных дислокационных ис-точников [7]. Их возникновение связано с поперечным скольжением винтовых участков дислокационных петель при их выходе из кристалла.…”

Section: Introductionunclassified

“…Можно ожидать, что часть отмеченных выше особенностей низкоскоростной пластической деформации наноразмер-ных кристаллов будет присуща и их высокоскоростной (ε > 10 3 s −1 ) и ударной (ε > 10 5 s −1 ) пластической де-формации. Следует заметить, что из-за эксперименталь-ных трудностей осуществления реальных ударных экс-периментов с нанокристаллами имеющиеся в настоящее время сведения об их поведении при сжатии получены при компьютерном МД [6,13] и мультимасштабном дискретно-дислокационном 3-D [7,14,20] моделировании процесса их пластической деформации.…”

Section: Introductionunclassified

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Размерные Эффекты При Ударном Пластическом Сжатии Наноразмерных Кристаллов

Малыгин¹,

Клявин²

2017

Физика Твердого Тела

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В рамках дислокационно-кинетического подхода, основанного на уравнениях и соотношениях кинетики дислокаций, впервые сделан теоретический анализ размерных эффектов при ударно-пластическом сжатии наноразмерных кристаллов. Получены количественные соотношения для зависимости предела текучести кристаллов τy от размера их поперечного сечения D и скорости ударной деформацииε, τy ∼ε 2/3 D. Указанный вид зависимости имеет место при релаксации упругих напряжений в результате эмиссии дислокаций из однополюсных источников Франка−Рида вблизи поверхности кристалла.

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Section: Introductionunclassified

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Размерные Эффекты При Ударном Пластическом Сжатии Наноразмерных Кристаллов

Малыгин¹,

Клявин²

2017

Физика Твердого Тела

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“…40 dislocation dynamics (DDD). The computational framework for DDD has reached a level of maturity for some problems, primarily where the plastically deforming volumes are highly constrained, such as in micropillars [47][48][49][50][51][52][53][54][55][56] and thin films [57][58][59][60][61][62][63][64][65] (Fig. 5).…”

Section: The Science Base For Property Prediction Across Length Scalesmentioning

confidence: 99%

Emerging Science and Research Opportunities for Metals and Metallic Nanostructures

Handwerker

Pollock

2014

JOM

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During the next decade, fundamental research on metals and metallic nanostructures (MMNs) has the potential to continue transforming metals science into innovative materials, devices, and systems. A workshop to identify emerging and potentially transformative research areas in MMNs was held June 13 and 14, 2012, at the University of California Santa Barbara. There were 47 attendees at the workshop (listed in the Acknowledgements section), representing a broad range of academic institutions, industry, and government laboratories. The metals and metallic nanostructures (MMNs) workshop aimed to identify significant research trends, scientific fundamentals, and recent breakthroughs that can enable new or enhanced MMN performance, either alone or in a more complex materials system, for a wide range of applications. Additionally, the role that MMN research can play in high-priority research and development (R&D) areas such as the U.S. Materials Genome Initiative, the National Nanotechnology Initiative, the Advanced Manufacturing Initiative, and other similar initiatives that exist internationally was assessed. The workshop also addressed critical issues related to materials research instrumentation and the cyberinfrastructure for materials science research and education, as well as science, technology, engineering, and mathematics (STEM) workforce development, with emphasis on the United States but with an appreciation that similar challenges and opportunities for the materials community exist internationally. A central theme of the workshop was that research in MMNs has provided and will continue to provide societal benefits through the integration of experiment, theory, and simulation to link atomistic, nanoscale, microscale, and mesoscale phenomena across time scales for an ever-widening range of applications. Within this overarching theme, the workshop participants identified emerging research opportunities that are categorized and described in more detail in the following sections in terms of the following: three-dimensional (3-D) and fourdimensional (4-D) materials science. Structure evolution and the challenge of heterogeneous and multicomponent systems. The science base for property prediction across the length scales. Nanoscale phenomena at surfaces-experiment, theory, and simulation. Prediction and control of the morphology, microstructure, and properties of ''bulk'' nanostructured metals. Functionality and control of materials far from equilibrium. Hybrid and multifunctional materials assemblies. Materials discovery and design: enhancing the theory-simulation-experiment loop. Following an introduction, these emerging research opportunities are discussed in detail, along with challenges and opportunities for the materials community in the areas of instrumentation, cyberinfrastructure, education, and workforce development.

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“…For instance, at the microlevel, several attempts have been made to simulate dislocation microstructures governing the plastic flow in metals [9][10][11][12]. Dislocation dynamics simulations have also been performed to examine plasticity in FCC metals like Ni [13] and Cu [14,15]. Yellakara et al [16] examined the effect of grain shape and size on the deformation behavior of polycrystalline Cu using DD simulations.…”

Section: Introductionmentioning

confidence: 99%

Multiscale modeling of plasticity in a copper single crystal deformed at high strain rates

Chandra

Samal

Chavan

et al. 2015

Plasticity and Mechanics of Defects

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A hierarchical multiscale modeling approach is presented to predict the mechanical response of dynamically deformed (1100 s −1 −4500 s −1 ) copper single crystal in two different crystallographic orientations. An attempt has been made to bridge the gap between nano-, micro-and meso-scales. In view of this, Molecular Dynamics (MD) simulations at nanoscale are performed to quantify the drag coefficient for dislocations which has been exploited in Dislocation Dynamics (DD) regime at the microscale. Discrete dislocation dynamics simulations are then performed to calculate the hardening parameters required by the physics based Crystal Plasticity (CP) model at the mesoscale. The crystal plasticity model employed is based on thermally activated theory for plastic flow. Crystal plasticity simulations are performed to quantify the mechanical response of the copper single crystal in terms of stressstrain curves and shape changes under dynamic loading. The deformation response obtained from CP simulations is in good agreement with the experimental data.

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Discrete dislocation dynamics simulations of plasticity at small scales

Cited by 149 publications

References 62 publications

Размерные Эффекты При Ударном Пластическом Сжатии Наноразмерных Кристаллов

Размерные Эффекты При Ударном Пластическом Сжатии Наноразмерных Кристаллов

Emerging Science and Research Opportunities for Metals and Metallic Nanostructures

Multiscale modeling of plasticity in a copper single crystal deformed at high strain rates

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