Thermal activation and ductile vs. brittle behavior of microcracks in 3D BCC iron crystals under biaxial loading by atomistic simulations

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388998%3A_____%2F20%3A00536302" target="_blank" >RIV/61388998:_____/20:00536302 - isvavai.cz</a>

Výsledek na webu

<a href="https://www.mdpi.com/2075-4701/10/11/1525" target="_blank" >https://www.mdpi.com/2075-4701/10/11/1525</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3390/met10111525" target="_blank" >10.3390/met10111525</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Thermal activation and ductile vs. brittle behavior of microcracks in 3D BCC iron crystals under biaxial loading by atomistic simulations

Popis výsledku v původním jazyce

We present the results of free 3D molecular dynamics (MD) simulations, focused on the influence of temperature on the ductile-brittle behavior of a pre-existing central Gri_th throughnmicrocrack (110)[110] (crack plane/crack front) under biaxial loading _A and _B in tension mode I. At temperatures of 300 K and 600 K, the MD results provide new information on the thresholdnvalues of the stress intensity factor K and the energy release rate G, needed for the emission of <111>{112} blunting dislocations that support crack stability. A simple procedure for the evaluation of thermal activation from MD results is proposed in the paper. 3D atomistic results are compared with continuum predictions on thermal activation of the crack induced dislocation generation. At elevatedntemperature T and biaxiality ratios _B/_A _ 0.8 dislocation emission in MD is observed, supported by thermal activation energy of about ~30 kBT.With increasing temperature, the ductile-brittle transition moves to a higher biaxiality ratios in comparison with the situation at temperature of ~0 K. Near the transition, dislocation emission occurs at lower loadings than expected by continuum predictions. For the ratios _B/_A _ 1, the elevated temperature facilitates (surprisingly) the microcrack growth below Gri_th level.

Název v anglickém jazyce

Thermal activation and ductile vs. brittle behavior of microcracks in 3D BCC iron crystals under biaxial loading by atomistic simulations

Popis výsledku anglicky

We present the results of free 3D molecular dynamics (MD) simulations, focused on the influence of temperature on the ductile-brittle behavior of a pre-existing central Gri_th throughnmicrocrack (110)[110] (crack plane/crack front) under biaxial loading _A and _B in tension mode I. At temperatures of 300 K and 600 K, the MD results provide new information on the thresholdnvalues of the stress intensity factor K and the energy release rate G, needed for the emission of <111>{112} blunting dislocations that support crack stability. A simple procedure for the evaluation of thermal activation from MD results is proposed in the paper. 3D atomistic results are compared with continuum predictions on thermal activation of the crack induced dislocation generation. At elevatedntemperature T and biaxiality ratios _B/_A _ 0.8 dislocation emission in MD is observed, supported by thermal activation energy of about ~30 kBT.With increasing temperature, the ductile-brittle transition moves to a higher biaxiality ratios in comparison with the situation at temperature of ~0 K. Near the transition, dislocation emission occurs at lower loadings than expected by continuum predictions. For the ratios _B/_A _ 1, the elevated temperature facilitates (surprisingly) the microcrack growth below Gri_th level.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

20501 - Materials engineering

Projekt

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

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2020

Kód důvěrnosti údajů

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

Název periodika

Metals

ISSN

2075-4701

e-ISSN

—

Svazek periodika

10

Číslo periodika v rámci svazku

11

Stát vydavatele periodika

CH - Švýcarská konfederace

Počet stran výsledku

27

Strana od-do

1525

Kód UT WoS článku

000594026400001

EID výsledku v databázi Scopus

2-s2.0-85096185768