Objasnění deformačních mechanismů při FCC a BCC nanokontaktu pomocí topografických analýz povrchu

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dc.contributor.authorVarillas Delgado, Javier
dc.contributor.authorOčenášek, Jan
dc.contributor.authorTorner, Jordi
dc.contributor.authorAlcalá, Jorge
dc.date.accessioned2018-02-21T11:35:18Z
dc.date.available2018-02-21T11:35:18Z
dc.date.issued2017
dc.description.abstractNanokontaktní zatížení skrývá potenciál pro výzkum plasticity krystalů ze skluzových čar, které jsou emitovány na povrch vzorku, a dalších deformací povrchu, kde individuální atomové terásky organizovány do větších výstupků a symetrických rozet. Naše MD simulace podrobně analyzují mechanismy interakce dislokací, dvojčatění i anihilaci poruch a ukazují charakteristické znaky deformačního procesu pro FCC a BCC krystaly.cs
dc.description.abstract-translatedNanocontact loadings offer the potential to investigate crystal plasticity from surface slip trace emissions and distinct pileup patterns where individual atomic terraces arrange into hillocks and symmetric rosettes. Our MD simulations in FCC Cu and Al nanocontacts show development of specific dislocation interception, cross-slip and twin annihilation mechanisms producing traces along characteristic <011> and <112> directions. Although planar slip is stabilized through subsurface dislocation interactions, highly serrated slip traces always predominate in Al due to the advent of cross-slip of the surfaced population of screw dislocations, leading to intricate hillock morphologies. We show that the distinct wavy hillocks and terraces in BCC Ta and Fe nanocontacts are due to dislocation kinking and outward spreading of surfaced screw segments, which originate from dislocation loops induced by twin annihilation and twin-mediated nucleation processes in the subsurface. While increasing temperature favors terrace formation in BCCs, surface decorations are enhanced in FCCs limiting hillock definition. It is found that material bulging against the indenter-tip is a distinctive feature in nanocontact plasticity associated with intermittent defect bursts. Bulging is enhanced by recurrent slip traces introduced throughout the contact surface, as in the case of the strongly linear defect networks in FCC Al, and by specific twin arrangements at the vicinity of BCC nanocontacts. Defect patterning also produces surface depressions in the form of vertexes around FCC nanoimprints. While the rosette morphologies are consistent with those assessed experimentally in greater FCC and BCC imprints, topographical pileup due to extensive bulging becomes prominent at the nanoscale.en
dc.format11 s.cs
dc.format.mimetypeapplication/pdf
dc.identifier.citationVARILLAS DELGADO, J., OČENÁŠEK, J., TORNER, J., ALCALÁ, J. Unraveling deformation mechanisms around FCC and BCC nanocontacts through slip trace and pileup topography analyses. Acta marerialia, 2017, roč. 125, č. 15 February 2017, s. 431-441. ISSN 1359-6454.en
dc.identifier.doi10.1016/j.actamat.2016.11.067
dc.identifier.issn1359-6454
dc.identifier.obd43918405
dc.identifier.urihttp://hdl.handle.net/11025/29187
dc.language.isoenen
dc.project.IDinfo:eu-repo/grantAgreetment/EC/Výpočetní a experimentální design pokročilých materiálů s novými funkcionalitami /CZ.02.1.01/0.0/0.0/15_003/0000358cs
dc.publisherElsevieren
dc.rights© Elsevieren
dc.rights.accessopenAccessen
dc.subjectnanokontaktcs
dc.subjectFCCcs
dc.subject.translatednanokontakten
dc.subject.translatedFCCen
dc.subject.translatedBCCen
dc.subject.translatedMDen
dc.titleObjasnění deformačních mechanismů při FCC a BCC nanokontaktu pomocí topografických analýz povrchucs
dc.titleUnraveling deformation mechanisms around FCC and BCC nanocontacts through slip trace and pileup topography analysesen
dc.typepostprintcs
dc.typečlánekcs
dc.typepostprinten
dc.typearticleen
dc.type.statusPeer-revieweden
dc.type.versionacceptedVersionen
dc.type.versionpublishedVersionen

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