Irreversible evolution of dislocation pile-ups during cyclic microcantilever bending
In single crystals, plastic deformations are predominantly governed by dislocation movement and interactions. The group of dislocations that creates strain gradients, known as geometrically necessary dislocations (GNDs), also deterministically contributes to strain hardening, micron-scale size effec...
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| Format: | Article |
| Language: | English |
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Elsevier
2024-02-01
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| Series: | Materials & Design |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S0264127524000546 |
| _version_ | 1827346227493076992 |
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| author | Dávid Ugi Kolja Zoller Kolos Lukács Zsolt Fogarassy István Groma Szilvia Kalácska Katrin Schulz Péter Dusán Ispánovity |
| author_facet | Dávid Ugi Kolja Zoller Kolos Lukács Zsolt Fogarassy István Groma Szilvia Kalácska Katrin Schulz Péter Dusán Ispánovity |
| author_sort | Dávid Ugi |
| collection | DOAJ |
| description | In single crystals, plastic deformations are predominantly governed by dislocation movement and interactions. The group of dislocations that creates strain gradients, known as geometrically necessary dislocations (GNDs), also deterministically contributes to strain hardening, micron-scale size effects, fatigue, and Bauschinger effect. During bending large strain gradients naturally emerge which makes this deformation mode exceptionally suitable to study the evolution of GNDs. Here we present bi-directional bending experiment of a Cu single crystalline microcantilever with in situ characterisation of the dislocation microstructure in terms of high-resolution electron backscatter diffraction (HR-EBSD). The experiments are complemented with dislocation density modelling to provide physical understanding of the collective dislocation phenomena. We find that dislocation pile-ups form around the neutral zone during initial bending, however, these do not dissolve upon reversed loading, rather they contribute to the development of a much more complex GND dominated microstructure. This irreversible process is analysed in detail in terms of the involved Burgers vectors and slip systems. We conclude that at this scale the most dominant role in the Bauschinger effect and corresponding strain hardening is played by short-range dislocation interactions. The in-depth understanding of these phenomena will aid the design of microscopic metallic components with increased performance and reliability. |
| first_indexed | 2024-03-07T23:25:04Z |
| format | Article |
| id | doaj.art-b88f3c4e11a6472dab366148e308fbe1 |
| institution | Directory Open Access Journal |
| issn | 0264-1275 |
| language | English |
| last_indexed | 2024-03-07T23:25:04Z |
| publishDate | 2024-02-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Materials & Design |
| spelling | doaj.art-b88f3c4e11a6472dab366148e308fbe12024-02-21T05:24:03ZengElsevierMaterials & Design0264-12752024-02-01238112682Irreversible evolution of dislocation pile-ups during cyclic microcantilever bendingDávid Ugi0Kolja Zoller1Kolos Lukács2Zsolt Fogarassy3István Groma4Szilvia Kalácska5Katrin Schulz6Péter Dusán Ispánovity7ELTE Eötvös Loránd University, Department of Materials Physics, Pázmány Péter sétany 1/a, 1117 Budapest, Hungary; HUN-REN Research Centre for Natural Sciences, Institute of Materials and Environmental Chemistry, Magyar tudósok körútja 2, 1117 Budapest, HungaryKarlsruhe Institute of Technology, Institute for Applied Materials (IAM), Kaiserstr. 12, 76131 Karlsruhe, Germany; Hochschule Karlsruhe - University of Applied Sciences (HKA), Moltkestr. 30, 76133 Karlsruhe, GermanyELTE Eötvös Loránd University, Department of Materials Physics, Pázmány Péter sétany 1/a, 1117 Budapest, HungaryHUN-REN Centre for Energy Research, Institute of Technical Physics and Materials Science, Konkoly Thege M. út 29-33, 1121 Budapest, HungaryELTE Eötvös Loránd University, Department of Materials Physics, Pázmány Péter sétany 1/a, 1117 Budapest, HungaryMines Saint-Etienne, Univ Lyon, CNRS, UMR 5307 LGF, Centre SMS, 158 cours Fauriel 42023 Saint-Étienne, France; Corresponding authors.Karlsruhe Institute of Technology, Institute for Applied Materials (IAM), Kaiserstr. 12, 76131 Karlsruhe, Germany; Hochschule Karlsruhe - University of Applied Sciences (HKA), Moltkestr. 30, 76133 Karlsruhe, Germany; Corresponding authors.ELTE Eötvös Loránd University, Department of Materials Physics, Pázmány Péter sétany 1/a, 1117 Budapest, Hungary; Institute for Advanced Simulation: Materials Data Science and Informatics (IAS-9), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany; Corresponding authors.In single crystals, plastic deformations are predominantly governed by dislocation movement and interactions. The group of dislocations that creates strain gradients, known as geometrically necessary dislocations (GNDs), also deterministically contributes to strain hardening, micron-scale size effects, fatigue, and Bauschinger effect. During bending large strain gradients naturally emerge which makes this deformation mode exceptionally suitable to study the evolution of GNDs. Here we present bi-directional bending experiment of a Cu single crystalline microcantilever with in situ characterisation of the dislocation microstructure in terms of high-resolution electron backscatter diffraction (HR-EBSD). The experiments are complemented with dislocation density modelling to provide physical understanding of the collective dislocation phenomena. We find that dislocation pile-ups form around the neutral zone during initial bending, however, these do not dissolve upon reversed loading, rather they contribute to the development of a much more complex GND dominated microstructure. This irreversible process is analysed in detail in terms of the involved Burgers vectors and slip systems. We conclude that at this scale the most dominant role in the Bauschinger effect and corresponding strain hardening is played by short-range dislocation interactions. The in-depth understanding of these phenomena will aid the design of microscopic metallic components with increased performance and reliability.http://www.sciencedirect.com/science/article/pii/S0264127524000546Micromechanical testingCantilever bendingCopper single crystalContinuum dislocation dynamics simulationHR-EBSDGND density |
| spellingShingle | Dávid Ugi Kolja Zoller Kolos Lukács Zsolt Fogarassy István Groma Szilvia Kalácska Katrin Schulz Péter Dusán Ispánovity Irreversible evolution of dislocation pile-ups during cyclic microcantilever bending Materials & Design Micromechanical testing Cantilever bending Copper single crystal Continuum dislocation dynamics simulation HR-EBSD GND density |
| title | Irreversible evolution of dislocation pile-ups during cyclic microcantilever bending |
| title_full | Irreversible evolution of dislocation pile-ups during cyclic microcantilever bending |
| title_fullStr | Irreversible evolution of dislocation pile-ups during cyclic microcantilever bending |
| title_full_unstemmed | Irreversible evolution of dislocation pile-ups during cyclic microcantilever bending |
| title_short | Irreversible evolution of dislocation pile-ups during cyclic microcantilever bending |
| title_sort | irreversible evolution of dislocation pile ups during cyclic microcantilever bending |
| topic | Micromechanical testing Cantilever bending Copper single crystal Continuum dislocation dynamics simulation HR-EBSD GND density |
| url | http://www.sciencedirect.com/science/article/pii/S0264127524000546 |
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