Thermally-activated dislocation mobility in bcc metals : an accelerated molecular dynamics study

dc.contributor.authorGrabowski, Blazej
dc.contributor.authorZotov, Nikolay
dc.date.accessioned2022-08-24T06:35:35Z
dc.date.available2022-08-24T06:35:35Z
dc.date.issued2021de
dc.description.abstractPlastic deformation in metals is controlled by dislocation density and mobility. In bcc metals the mobility of screw dislocations, which takes place by temperature- and stress-driven nucleation of critical kink-pairs, is most essential for deformation. However, the critical resolved shear stresses at low temperatures, as determined from molecular dynamics (MD) simulations performed at constant strain rate, are typically 2–3 times larger than the yield stresses measured experimentally. Here, an accelerated MD procedure is developed and employed to investigate the onset of dislocation mobility in the prototypical system bcc Nb. The method combines constant strain and temperature MD with hyperdynamics, using a bond-boost potential. We demonstrate, with a careful statistical analysis, that the method enables nucleation of critical kink-pairs and the determination of the Gibbs energy of kink-pair formation from accelerated MD simulations at experimentally-measured shear stresses.en
dc.identifier.issn0927-0256
dc.identifier.other1815200278
dc.identifier.urihttp://nbn-resolving.de/urn:nbn:de:bsz:93-opus-ds-123182de
dc.identifier.urihttp://elib.uni-stuttgart.de/handle/11682/12318
dc.identifier.urihttp://dx.doi.org/10.18419/opus-12301
dc.language.isoende
dc.relationinfo:eu-repo/grantAgreement/EC/H2020/865855de
dc.relation.uridoi:10.1016/j.commatsci.2021.110804de
dc.rightsinfo:eu-repo/semantics/openAccessde
dc.subject.ddc530de
dc.titleThermally-activated dislocation mobility in bcc metals : an accelerated molecular dynamics studyen
dc.typearticlede
ubs.fakultaetChemiede
ubs.institutInstitut für Materialwissenschaftde
ubs.publikation.seiten10de
ubs.publikation.sourceComputational materials science 200 (2021), article 110804de
ubs.publikation.typZeitschriftenartikelde

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