The Effect of Hydrogen on the Stress-Strain Response in Fe3Al: An ab initio Molecular-Dynamics Study

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dc.contributor.authorŠesták, Petrcs
dc.contributor.authorFriák, Martincs
dc.contributor.authorŠob, Mojmírcs
dc.coverage.issue15cs
dc.coverage.volume14cs
dc.date.accessioned2021-09-22T14:57:29Z
dc.date.available2021-09-22T14:57:29Z
dc.date.issued2021-07-26cs
dc.description.abstractWe performed a quantum-mechanical molecular-dynamics (MD) study of Fe3Al with and without hydrogen atoms under conditions of uniaxial deformation up to the point of fracture. Addressing a long-lasting problem of hydrogen-induced brittleness of iron-aluminides under ambient conditions, we performed our density-functional-theory (DFT) MD simulations for T = 300 K (room temperature). Our MD calculations include a series of H concentrations ranging from 0.23 to 4 at.% of H and show a clear preference of H atoms for tetrahedral-like interstitial positions within the D0(3) lattice of Fe3Al. In order to shed more light on these findings, we performed a series of static lattice-simulations with the H atoms located in different interstitial sites. The H atoms in two different types of octahedral sites (coordinated by either one Al and five Fe atoms or two Al and four Fe atoms) represent energy maxima. Our structural relaxation of the H atoms in the octahedral sites lead to minimization of the energy when the H atom moved away from this interstitial site into a tetrahedral-like position with four nearest neighbors representing an energy minimum. Our ab initio MD simulations of uniaxial deformation along the < 001 > crystallographic direction up to the point of fracture reveal that the hydrogen atoms are located at the newly-formed surfaces of fracture planes even for the lowest computed H concentrations. The maximum strain associated with the fracture is then lower than that of H-free Fe3Al. We thus show that the hydrogen-related fracture initiation in Fe3Al in the case of an elastic type of deformation as an intrinsic property which is active even if all other plasticity mechanism are absent. The newly created fracture surfaces are partly non-planar (not atomically flat) due to thermal motion and, in particular, the H atoms creating locally different environments.en
dc.formattextcs
dc.format.extent1-14cs
dc.format.mimetypeapplication/pdfcs
dc.identifier.citationMaterials . 2021, vol. 14, issue 15, p. 1-14.en
dc.identifier.doi10.3390/ma14154155cs
dc.identifier.issn1996-1944cs
dc.identifier.other172471cs
dc.identifier.urihttp://hdl.handle.net/11012/201647
dc.language.isoencs
dc.publisherMDPIcs
dc.relation.ispartofMaterialscs
dc.relation.urihttps://www.mdpi.com/1996-1944/14/15/4155cs
dc.rightsCreative Commons Attribution 4.0 Internationalcs
dc.rights.accessopenAccesscs
dc.rights.sherpahttp://www.sherpa.ac.uk/romeo/issn/1996-1944/cs
dc.rights.urihttp://creativecommons.org/licenses/by/4.0/cs
dc.subjectFe3Alen
dc.subjecthydrogenen
dc.subjectembrittlementen
dc.subjectmolecular dynamicsen
dc.subjectstrengthen
dc.subjectab initioen
dc.subjectfractureen
dc.titleThe Effect of Hydrogen on the Stress-Strain Response in Fe3Al: An ab initio Molecular-Dynamics Studyen
dc.type.driverarticleen
dc.type.statusPeer-revieweden
dc.type.versionpublishedVersionen
sync.item.dbidVAV-172471en
sync.item.dbtypeVAVen
sync.item.insts2021.09.22 16:57:29en
sync.item.modts2021.09.22 16:14:55en
thesis.grantorVysoké učení technické v Brně. Středoevropský technologický institut VUT. Příprava a charakterizace nanostrukturcs
thesis.grantorVysoké učení technické v Brně. Fakulta strojního inženýrství. Ústav fyzikálního inženýrstvícs
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Ústav fyzikálního inženýrství
Příprava a charakterizace nanostruktur