Number of the records: 1
Thermal activation and ductile vs. brittle behavior of microcracks in 3D BCC iron crystals under biaxial loading by atomistic simulations
- 1.
SYSNO ASEP 0536302 Document Type J - Journal Article R&D Document Type Journal Article Subsidiary J Článek ve WOS Title Thermal activation and ductile vs. brittle behavior of microcracks in 3D BCC iron crystals under biaxial loading by atomistic simulations Author(s) Uhnáková, Alena (UT-L) RID, ORCID
Machová, Anna (UT-L) RID, ORCID
Hora, Petr (UT-L) RID, ORCIDNumber of authors 3 Article number 1525 Source Title Metals. - : MDPI
Roč. 10, č. 11 (2020)Number of pages 27 s. Publication form Print - P Language eng - English Country CH - Switzerland Keywords thermal activation ; ductile-brittle transition ; T-stress ; bcc iron ; molecular dynamics Subject RIV BJ - Thermodynamics OECD category Materials engineering R&D Projects GA17-12925S GA ČR - Czech Science Foundation (CSF) EF15_003/0000493 GA MŠMT - Ministry of Education, Youth and Sports (MEYS) TK01030108 GA TA ČR - Technology Agency of the Czech Republic (TA ČR) Method of publishing Open access Institutional support UT-L - RVO:61388998 UT WOS 000594026400001 EID SCOPUS 85096185768 DOI 10.3390/met10111525 Annotation 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 through
microcrack (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 threshold
values 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 elevated
temperature 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.Workplace Institute of Thermomechanics Contact Marie Kajprová, kajprova@it.cas.cz, Tel.: 266 053 154 ; Jana Lahovská, jaja@it.cas.cz, Tel.: 266 053 823 Year of Publishing 2021 Electronic address https://www.mdpi.com/2075-4701/10/11/1525
Number of the records: 1