Grain-level mechanism of plastic deformation in harmonic structure materials revealed by high resolution X-ray diffraction
Sjögren-Levin, Elis LU
; Pantleon, Wolfgang
; Ahadi, Aylin
LU
; Hegedüs, Zoltan
; Lienert, Ulrich
; Tsuji, Nobuhiro
; Ameyama, Kei
and Orlov, Dmytro
LU
(2024)
In Acta Materialia
265.
- Abstract
Materials with heterogeneous microstructures have been reported to have an attractive combination of strength and ductility. This is attributed to synergistic strengthening effects from the difference in strength of fine- and coarse-grained regions. Understanding the interaction of the regions is crucial for further optimization of the microstructures. In this work, we fabricated nickel of harmonic structure (HS) and a reference with homogenous coarse grains. The HS constitutes of an interconnected fine-grained network that surrounds regions of coarse grains. The interplay of the regions was studied by monitoring Bragg reflections from individual grains in situ during tensile deformation until approximately 2 % strain through... (More)
Materials with heterogeneous microstructures have been reported to have an attractive combination of strength and ductility. This is attributed to synergistic strengthening effects from the difference in strength of fine- and coarse-grained regions. Understanding the interaction of the regions is crucial for further optimization of the microstructures. In this work, we fabricated nickel of harmonic structure (HS) and a reference with homogenous coarse grains. The HS constitutes of an interconnected fine-grained network that surrounds regions of coarse grains. The interplay of the regions was studied by monitoring Bragg reflections from individual grains in situ during tensile deformation until approximately 2 % strain through synchrotron X-ray diffraction. The technique allows grain-level assessment of the degree of plastic deformation. Two grains were followed in the reference and two small grains (fine-grained region) and two large grains (coarse-grained region) in the HS. Three deformation regimes were identified: elastic deformation, onset of plastic deformation and significant plastic deformation. Our results reveal that the large grains in the harmonic structure onset plastic deformation during the macroscopic elastic stage. With increasing applied stress, the small grains yield plastically also and once a large fraction of the fine-grained network deforms plastically the large grains undergo significant plastic deformation. Notably, the onset of significant plastic deformation of large grains in the HS occurs at approximately 100 MPa higher applied stress than in the grains in the reference. This shows that fine grains constrain the large grains from deforming plastically in the HS.
(Less)
- author
- Sjögren-Levin, Elis
LU
; Pantleon, Wolfgang
; Ahadi, Aylin
LU
; Hegedüs, Zoltan
; Lienert, Ulrich
; Tsuji, Nobuhiro
; Ameyama, Kei
and Orlov, Dmytro
LU
- organization
- publishing date
- 2024-02-15
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Harmonic structure material, Heterogeneous structure, Plastic flow properties, Reciprocal space mapping, Synchrotron diffraction
- in
- Acta Materialia
- volume
- 265
- article number
- 119623
- publisher
- Elsevier
- external identifiers
-
- scopus:85181937667
- ISSN
- 1359-6454
- DOI
- 10.1016/j.actamat.2023.119623
- language
- English
- LU publication?
- yes
- additional info
- Publisher Copyright: © 2023 The Author(s)
- id
- 18722d00-5a70-4160-9429-906d39aa906e
- date added to LUP
- 2024-01-16 18:21:15
- date last changed
- 2024-02-09 11:51:54
@article{18722d00-5a70-4160-9429-906d39aa906e,
abstract = {{<p>Materials with heterogeneous microstructures have been reported to have an attractive combination of strength and ductility. This is attributed to synergistic strengthening effects from the difference in strength of fine- and coarse-grained regions. Understanding the interaction of the regions is crucial for further optimization of the microstructures. In this work, we fabricated nickel of harmonic structure (HS) and a reference with homogenous coarse grains. The HS constitutes of an interconnected fine-grained network that surrounds regions of coarse grains. The interplay of the regions was studied by monitoring Bragg reflections from individual grains in situ during tensile deformation until approximately 2 % strain through synchrotron X-ray diffraction. The technique allows grain-level assessment of the degree of plastic deformation. Two grains were followed in the reference and two small grains (fine-grained region) and two large grains (coarse-grained region) in the HS. Three deformation regimes were identified: elastic deformation, onset of plastic deformation and significant plastic deformation. Our results reveal that the large grains in the harmonic structure onset plastic deformation during the macroscopic elastic stage. With increasing applied stress, the small grains yield plastically also and once a large fraction of the fine-grained network deforms plastically the large grains undergo significant plastic deformation. Notably, the onset of significant plastic deformation of large grains in the HS occurs at approximately 100 MPa higher applied stress than in the grains in the reference. This shows that fine grains constrain the large grains from deforming plastically in the HS.</p>}},
author = {{Sjögren-Levin, Elis and Pantleon, Wolfgang and Ahadi, Aylin and Hegedüs, Zoltan and Lienert, Ulrich and Tsuji, Nobuhiro and Ameyama, Kei and Orlov, Dmytro}},
issn = {{1359-6454}},
keywords = {{Harmonic structure material; Heterogeneous structure; Plastic flow properties; Reciprocal space mapping; Synchrotron diffraction}},
language = {{eng}},
month = {{02}},
publisher = {{Elsevier}},
series = {{Acta Materialia}},
title = {{Grain-level mechanism of plastic deformation in harmonic structure materials revealed by high resolution X-ray diffraction}},
url = {{http://dx.doi.org/10.1016/j.actamat.2023.119623}},
doi = {{10.1016/j.actamat.2023.119623}},
volume = {{265}},
year = {{2024}},
}