Atomistic insight into the dislocation nucleation at crystalline/crystalline and crystalline/amorphous interfaces without full symmetry

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61989100%3A27740%2F19%3A10240036" target="_blank" >RIV/61989100:27740/19:10240036 - isvavai.cz</a>

Výsledek na webu

<a href="https://www.researchgate.net/publication/328045347_Atomistic_insight_into_the_dislocation_nucleation_at_crystallinecrystalline_and_crystallineamorphous_interfaces_without_full_symmetry" target="_blank" >https://www.researchgate.net/publication/328045347_Atomistic_insight_into_the_dislocation_nucleation_at_crystallinecrystalline_and_crystallineamorphous_interfaces_without_full_symmetry</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.actamat.2018.09.068" target="_blank" >10.1016/j.actamat.2018.09.068</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Atomistic insight into the dislocation nucleation at crystalline/crystalline and crystalline/amorphous interfaces without full symmetry

Popis výsledku v původním jazyce

Misfit dislocations at bimetal interfaces play a decisive role in determining various deformation behaviors by carrying the shear sliding, serving as a barrier for dislocation transmission and a source of dislocation nucleation. However, when the interface does not possess the distinct feature of misfit dislocations, the nucleation mechanism of lattice dislocations at the interfaces cannot be simply quantified by previously developed atomistic mechanisms based on characteristic misfit dislocations. Using crystalline/crystalline interfaces with a large lattice mismatch and crystalline/amorphous interfaces without local symmetry as prototypes, we show for the first time that the dislocation nucleation at such interfaces is attributable to the localized strain heterogeneities by modifying the volumetric and shear strain components at the atomic level to mechanically respond to different loadings. Using atomic strain tensor analysis, we found that in-plane localized shearing plays a critical role in the emission of lattice dislocations from interfaces, while the corresponding normal components of the volumetric strain tensor will dominate the character of the nucleated lattice dislocation by modifying the atomic excess volume at the interface to overcome the barrier to dislocation nucleation. Further exploration of various crystalline/amorphous interfaces by varying the chemical composition of the amorphous side indicates that chemical heterogeneity may substantially change the strain heterogeneity by forming a different clustered structure at the interface, resulting in the preferred choice of nucleation sites at the boundary regions that can be defined as nano shear traces (NSTs). These results provide a foundation to investigate the effects of strain and chemical heterogeneities in order to provide a realistic explanation of interface mediated deformation mechanisms and an efficient solution to tune interface dominated plasticity. (C) 2018 Published by Elsevier Ltd on behalf of Acta Materialia Inc.

Název v anglickém jazyce

Atomistic insight into the dislocation nucleation at crystalline/crystalline and crystalline/amorphous interfaces without full symmetry

Popis výsledku anglicky

Misfit dislocations at bimetal interfaces play a decisive role in determining various deformation behaviors by carrying the shear sliding, serving as a barrier for dislocation transmission and a source of dislocation nucleation. However, when the interface does not possess the distinct feature of misfit dislocations, the nucleation mechanism of lattice dislocations at the interfaces cannot be simply quantified by previously developed atomistic mechanisms based on characteristic misfit dislocations. Using crystalline/crystalline interfaces with a large lattice mismatch and crystalline/amorphous interfaces without local symmetry as prototypes, we show for the first time that the dislocation nucleation at such interfaces is attributable to the localized strain heterogeneities by modifying the volumetric and shear strain components at the atomic level to mechanically respond to different loadings. Using atomic strain tensor analysis, we found that in-plane localized shearing plays a critical role in the emission of lattice dislocations from interfaces, while the corresponding normal components of the volumetric strain tensor will dominate the character of the nucleated lattice dislocation by modifying the atomic excess volume at the interface to overcome the barrier to dislocation nucleation. Further exploration of various crystalline/amorphous interfaces by varying the chemical composition of the amorphous side indicates that chemical heterogeneity may substantially change the strain heterogeneity by forming a different clustered structure at the interface, resulting in the preferred choice of nucleation sites at the boundary regions that can be defined as nano shear traces (NSTs). These results provide a foundation to investigate the effects of strain and chemical heterogeneities in order to provide a realistic explanation of interface mediated deformation mechanisms and an efficient solution to tune interface dominated plasticity. (C) 2018 Published by Elsevier Ltd on behalf of Acta Materialia Inc.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10302 - Condensed matter physics (including formerly solid state physics, supercond.)

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2019

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Acta Materialia

ISSN

1359-6454

e-ISSN

—

Svazek periodika

162

Číslo periodika v rámci svazku

-

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

12

Strana od-do

255-267

Kód UT WoS článku

000450381400022

EID výsledku v databázi Scopus

2-s2.0-85054693186