Atomistic studies of ductile fracture of a single crystalline cantor alloy containing a crack at cryogenic temperatures

In this paper, atomistic studies show that Cantor alloys containing a pre-existing crack under tension are ductile at cryogenic temperatures. Specifically, the effects of crack length on the mechanical properties of single-crystalline Cantor alloys under mode I loading at the temperature of 0.1 K ar...

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Main Authors: Ji, Weiming, Wu, Mao See
Other Authors: School of Mechanical and Aerospace Engineering
Format: Article
Language:English
Published: 2022
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Online Access:https://hdl.handle.net/10356/159463
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Institution: Nanyang Technological University
Language: English
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spelling sg-ntu-dr.10356-1594632023-08-15T08:04:58Z Atomistic studies of ductile fracture of a single crystalline cantor alloy containing a crack at cryogenic temperatures Ji, Weiming Wu, Mao See School of Mechanical and Aerospace Engineering Engineering::Mechanical engineering Cantor Alloys Molecular Dynamics In this paper, atomistic studies show that Cantor alloys containing a pre-existing crack under tension are ductile at cryogenic temperatures. Specifically, the effects of crack length on the mechanical properties of single-crystalline Cantor alloys under mode I loading at the temperature of 0.1 K are investigated via molecular dynamics (MD) simulations. For different initial crack lengths ranging from 25 to 45 nm, the J-integral is calculated at the critical point of dislocation emission, and the work-of-fracture is calculated at the fracture strain. The results show that the Young's modulus and yield stress decrease with the increased crack length. The J-integral is not significantly affected by the crack length, due to the fact it is governed by the length-independent unstable stacking fault energy. However, the work-of-fracture increases with increased crack length. Nucleation and growth of nanosized cavities in front of the crack tip are observed and the crack propagates through coalescence of cavities, which agrees well with previous experimental findings. As the tensile strain increases, there is a transition from cavitation to shear faulting, after which the stress-strain responses are independent of the crack length. The cavitation and shear faulting dissipate a large amount of energy needed for crack propagation, leading to ductile fracture of Cantor alloys at cryogenic temperatures. Ministry of Education (MOE) This research is supported by the Ministry of Education, Singapore, under its Academic Research Fund Tier 1, Project Number RG155/19 (S). The computational work for this article was performed using resources of the Singapore National Supercomputing Centre under Project ID 12002312. 2022-06-24T02:36:34Z 2022-06-24T02:36:34Z 2021 Journal Article Ji, W. & Wu, M. S. (2021). Atomistic studies of ductile fracture of a single crystalline cantor alloy containing a crack at cryogenic temperatures. Engineering Fracture Mechanics, 258, 108120-. https://dx.doi.org/10.1016/j.engfracmech.2021.108120 0013-7944 https://hdl.handle.net/10356/159463 10.1016/j.engfracmech.2021.108120 2-s2.0-85119412885 258 108120 en RG155/19 (S) 12002312 Engineering Fracture Mechanics 10.21979/N9/DG1D4H © 2021 Elsevier Ltd. All rights reserved.
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic Engineering::Mechanical engineering
Cantor Alloys
Molecular Dynamics
spellingShingle Engineering::Mechanical engineering
Cantor Alloys
Molecular Dynamics
Ji, Weiming
Wu, Mao See
Atomistic studies of ductile fracture of a single crystalline cantor alloy containing a crack at cryogenic temperatures
description In this paper, atomistic studies show that Cantor alloys containing a pre-existing crack under tension are ductile at cryogenic temperatures. Specifically, the effects of crack length on the mechanical properties of single-crystalline Cantor alloys under mode I loading at the temperature of 0.1 K are investigated via molecular dynamics (MD) simulations. For different initial crack lengths ranging from 25 to 45 nm, the J-integral is calculated at the critical point of dislocation emission, and the work-of-fracture is calculated at the fracture strain. The results show that the Young's modulus and yield stress decrease with the increased crack length. The J-integral is not significantly affected by the crack length, due to the fact it is governed by the length-independent unstable stacking fault energy. However, the work-of-fracture increases with increased crack length. Nucleation and growth of nanosized cavities in front of the crack tip are observed and the crack propagates through coalescence of cavities, which agrees well with previous experimental findings. As the tensile strain increases, there is a transition from cavitation to shear faulting, after which the stress-strain responses are independent of the crack length. The cavitation and shear faulting dissipate a large amount of energy needed for crack propagation, leading to ductile fracture of Cantor alloys at cryogenic temperatures.
author2 School of Mechanical and Aerospace Engineering
author_facet School of Mechanical and Aerospace Engineering
Ji, Weiming
Wu, Mao See
format Article
author Ji, Weiming
Wu, Mao See
author_sort Ji, Weiming
title Atomistic studies of ductile fracture of a single crystalline cantor alloy containing a crack at cryogenic temperatures
title_short Atomistic studies of ductile fracture of a single crystalline cantor alloy containing a crack at cryogenic temperatures
title_full Atomistic studies of ductile fracture of a single crystalline cantor alloy containing a crack at cryogenic temperatures
title_fullStr Atomistic studies of ductile fracture of a single crystalline cantor alloy containing a crack at cryogenic temperatures
title_full_unstemmed Atomistic studies of ductile fracture of a single crystalline cantor alloy containing a crack at cryogenic temperatures
title_sort atomistic studies of ductile fracture of a single crystalline cantor alloy containing a crack at cryogenic temperatures
publishDate 2022
url https://hdl.handle.net/10356/159463
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