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dc.contributor.author
Bringa, Eduardo Marcial
dc.contributor.author
Traiviratana, Sirirat
dc.contributor.author
Meyers, Marc A.
dc.date.available
2024-08-21T10:27:25Z
dc.date.issued
2010-08
dc.identifier.citation
Bringa, Eduardo Marcial; Traiviratana, Sirirat; Meyers, Marc A.; Void initiation in fcc metals: Effect of loading orientation and nanocrystalline effects; Pergamon-Elsevier Science Ltd; Acta Materialia; 58; 13; 8-2010; 4458-4477
dc.identifier.issn
1359-6454
dc.identifier.uri
http://hdl.handle.net/11336/242913
dc.description.abstract
It is shown, through molecular dynamics simulations, that the emission and outward expansion of special dislocation loops, nucleated at the surface of nanosized voids, are responsible for the outward flux of matter, promoting their growth. Calculations performed for different orientations of the tensile axis, [0 0 1], [1 1 0] and [1 1 1], reveal new features of these loops for a face-centered cubic metal, copper, and show that their extremities remain attached to the surface of voids. There is a significant effect of the loading orientation on the sequence in which the loops form and interact. As a consequence, the initially spherical voids develop facets. Calculations reveal that loop emission occurs for voids with radii as low as 0.15 nm, containing two vacancies. This occurs at a von Mises stress approximately equal to 0.12G (where G is the shear modulus of the material), and is close to the stress at which dislocation loops nucleate homogeneously. The velocities of the leading partial dislocations are measured and found to be subsonic (∼1000 m s−1). It is shown, for nanocrystalline metals that void initiation takes place at grain boundaries and that their growth proceeds by grain boundary debonding and partial dislocation emission into the grains. The principal difference with monocrystals is that the voids do not become spherical and that their growth proceeds along the boundaries. Differences in stress states (hydrostatic and uniaxial strain) are discussed. The critical stress for void nucleation and growth in the nanocrystalline metal is considerably lower than in the monocrystalline case by virtue of the availability of nucleation sites at grain boundaries (von Mises stress ∼0.05G). This suggests a hierarchy of nucleation sites in materials, starting with dispersed phases, triple points and grain boundaries, and proceeding with vacancy complexes up to divacancies.
dc.format
application/pdf
dc.language.iso
eng
dc.publisher
Pergamon-Elsevier Science Ltd
dc.rights
info:eu-repo/semantics/openAccess
dc.rights.uri
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
dc.subject
molecular dynamics
dc.subject
dislocations
dc.subject
copper
dc.subject
nanostructure
dc.subject
voids
dc.subject.classification
Física de los Materiales Condensados
dc.subject.classification
Ciencias Físicas
dc.subject.classification
CIENCIAS NATURALES Y EXACTAS
dc.title
Void initiation in fcc metals: Effect of loading orientation and nanocrystalline effects
dc.type
info:eu-repo/semantics/article
dc.type
info:ar-repo/semantics/artículo
dc.type
info:eu-repo/semantics/publishedVersion
dc.date.updated
2024-08-19T11:49:24Z
dc.journal.volume
58
dc.journal.number
13
dc.journal.pagination
4458-4477
dc.journal.pais
Estados Unidos
dc.description.fil
Fil: Bringa, Eduardo Marcial. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; Argentina
dc.description.fil
Fil: Traiviratana, Sirirat. University of California at San Diego; Estados Unidos
dc.description.fil
Fil: Meyers, Marc A.. University of California at San Diego; Estados Unidos
dc.journal.title
Acta Materialia
dc.relation.alternativeid
info:eu-repo/semantics/altIdentifier/url/http://www.sciencedirect.com/science/article/pii/S1359645410002594
dc.relation.alternativeid
info:eu-repo/semantics/altIdentifier/doi/http://dx.doi.org/10.1016/j.actamat.2010.04.043
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