Mechanical behavior of Σ tilt grain boundaries in nanoscale Cu and Al: A quasicontinuum study

Sansoz, Frédéric; Molinari, Jean‐François

doi:10.1016/j.actamat.2005.01.007

Cited by 208 publications

(149 citation statements)

References 64 publications

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“…There are not so many ab initio results of metallic GBs using LDA (local density approximation) or GGA as compared with classical computations using the embedded-atom method. 34,35) For Cu GBs, the boundary energies are 1270 mJ/m 2 (GGA) for the {210}/ [001] AE ¼ 5 tilt GB, 36) 22) and 502 mJ/m 2 for the {210}/[001] AE ¼ 5 tilt GB. 40) At least on the energy range, the agreement between our results and these results is good.…”

Section: Comparison With Other Ab Initio Resultsmentioning

confidence: 99%

First-Principles Study of the Stability and Interfacial Bonding of Tilt and Twist Grain Boundaries in Al and Cu

et al. 2009

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Nature of grain boundaries (GBs) should affect the micro-structural evolution and mechanical properties of metallic micro-crystalline formed by severe plastic deformation. The stability and interfacial bonding of coincidence tilt and twist GBs in Al and Cu have been examined by using the projector-augmented wave method within the density-functional theory. For the {221} AE ¼ 9 tilt boundary, glide models are more stable than mirror models for Al and Cu, and the {001} AE ¼ 5 twist boundary is more stable than the AE ¼ 9 tilt boundary for Al and Cu, due to smaller structural distortions. There is a tendency that the boundary energies in Al are substantially smaller than those in Cu. This can be explained by the electronic and atomic behavior of bond reconstruction at the interfaces in Al, due to the covalent nature of Al as observed in the charge density distribution, in contrast to rather simple metallic bonding at Cu GBs.

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Section: Comparison With Other Ab Initio Resultsmentioning

confidence: 99%

First-Principles Study of the Stability and Interfacial Bonding of Tilt and Twist Grain Boundaries in Al and Cu

et al. 2009

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“…For the interested reader, some recent works have calculated the structures and energies for symmetric/asymmetric tilt/twist/ mixed character grain boundaries in Cu, Ni, and/or Al; [193][194][195] in particular, Olmsted et al 193 explored 388 distinct Ni and Al boundaries to ascertain relationships with grain boundary energy and grain boundary mobility. 196 These methods have been extended from energies to calculating the properties of individual grain boundaries in an effort to understand grain boundary mechanics, such as dislocation nucleation, [115][116][117][118]197 grain boundary sliding, 198 spall strength, 199,200 fracture, 201 and GBdislocation interactions. 202,203 In many cases, it was found that the grain boundary properties are not simply governed by the crystallographic orientations of the adjacent grains (e.g., see Ref.…”

Section: Grain Boundary (Bicrystal) MD Simulationsmentioning

confidence: 99%

“Bulk” Nanocrystalline Metals: Review of the Current State of the Art and Future Opportunities for Copper and Copper Alloys

Tschopp

Murdoch

Kecskes

et al. 2014

JOM

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It is a new beginning for innovative fundamental and applied science in nanocrystalline materials. Many of the processing and consolidation challenges that have haunted nanocrystalline materials are now more fully understood, opening the doors for bulk nanocrystalline materials and parts to be produced. While challenges remain, recent advances in experimental, computational, and theoretical capability have allowed for bulk specimens that have heretofore been pursued only on a limited basis. This article discusses the methodology for synthesis and consolidation of bulk nanocrystalline materials using mechanical alloying, the alloy development and synthesis process for stabilizing these materials at elevated temperatures, and the physical and mechanical properties of nanocrystalline materials with a focus throughout on nanocrystalline copper and a nanocrystalline Cu-Ta system, consolidated via equal channel angular extrusion, with properties rivaling that of nanocrystalline pure Ta. Moreover, modeling and simulation approaches as well as experimental results for grain growth, grain boundary processes, and deformation mechanisms in nanocrystalline copper are briefly reviewed and discussed. Integrating experiments and computational materials science for synthesizing bulk nanocrystalline materials can bring about the next generation of ultrahigh strength materials for defense and energy applications.

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“…The QC approach is a well-established method in the study of GB deformation in bicrystals as shown by past works [29,30]. In particular, the QC method was used in the very first study reporting the important role of E structural units in mediating GB sliding and GB-mediated dislocation nucleation, confirmed later by more complex MD simulations at finite temperature [34].…”

Section: Introductionmentioning

confidence: 93%

“…However, this latter study did not specifically address the impact of vacancies on the deformation modes and mechanical response of GBs. Also, atomistic simulations using the quasicontinuum (QC) method [27,28] have been performed to study the shearing of perfect crystalline interfaces with no defects [27,[29][30][31], as well as the effect of nanovoids in single crystals, i.e. without considering GBs [32].…”

Section: Introductionmentioning

confidence: 99%

Quasicontinuum study of the shear behavior of defective tilt grain boundaries in Cu

2014

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Atomistic simulations using the quasicontinuum method are used to study the role of vacancy defects and angström-scale voids on the mechanical behavior of five tilt bicrystals containing grain boundaries (GBs) that have been predicted to exhibit characteristic deformation processes of nanocrystalline and nanotwinned metals : GB-mediated dislocation emission, interface sliding, and shear-coupled GB migration. We demonstrate that such nanoscale defects have a profound impact on interfacial shear strength and underlying deformation mechanisms in copper GBs due to void-induced local stresses. In asymmetric high and low angle GBs, we find that voids become preferential sites for dislocation nucleation when the void size exceeds 4 Å. In symmetric Σ9(221) GBs prone to sliding, voids are shown to shield the local shear stress, which considerably reduces the extent of atom shuffling at the interface. In symmetric Σ5(210) and Σ27(115) GBs, we find that the effect of voids on shear-coupled GB migration depends on the GB tilt direction considered, as well as on the size and number of voids. Remarkably, large voids can completely abate the GB migration process in Σ27(115) GBs. For all GB types, the interfacial shear strength is shown to decrease linearly as the volume fraction of voids at the interface increases ; however, this study also suggests that this decrease is much more pronounced in GBs deforming by sliding than by dislocation nucleation or migration, owing to larger void-induced stresses.

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Mechanical behavior of Σ tilt grain boundaries in nanoscale Cu and Al: A quasicontinuum study

Cited by 208 publications

References 64 publications

First-Principles Study of the Stability and Interfacial Bonding of Tilt and Twist Grain Boundaries in Al and Cu

First-Principles Study of the Stability and Interfacial Bonding of Tilt and Twist Grain Boundaries in Al and Cu

“Bulk” Nanocrystalline Metals: Review of the Current State of the Art and Future Opportunities for Copper and Copper Alloys

Quasicontinuum study of the shear behavior of defective tilt grain boundaries in Cu

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