Size-dependent geometrically necessary dislocation structures in single-crystalline tungsten [PDF]
Journal of Materials Research, 2022 Abstract Wedge indentation experiments were conducted to study the depth dependence of geometrically necessary dislocation (GND) structures in single-crystalline tungsten. Single-crystalline tungsten exhibits a pronounced indentation size effect (ISE), which can be rationalized based on GNDs. The dislocation mechanisms,
Jin Wang +4 more
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Mechanical Engineering Journal, 2018 In this study, we investigated the mechanism of the indentation size effect based on measurement of the geometrically necessary (GN) dislocation density. The GN dislocation density was measured around impressions by electron backscatter diffraction (EBSD)
Shota HASUNUMA +3 more
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Geometrically necessary dislocation density distributions in cyclically deformed Ti–6Al–4V
Acta Materialia, 2012 Abstract Cross-correlation-based electron backscattering diffraction analysis has been used to map lattice rotations in Ti–6Al–4V polycrystals deformed by load-controlled fatigue and dwell fatigue including a hold at maximum load. The lattice curvatures were used to form lower bound estimates of the geometrically necessary dislocation (GND) density ...
Littlewood, P, Wilkinson, A
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Journal of Materials Research and TechnologyThis study presents a comprehensive analysis of time evolution and spatial distribution of crystallographic geometrically necessary dislocation (GND) density induced by solid-state thermal cycling in an IN718 polycrystal.
Anderson Nascimento, Irene J. Beyerlein
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FTMP-based simulations and evaluations of Geometrically-Necessary Boundaries (GNBs) of dislocation [PDF]
The International Journal of Multiphysics, 2019 The present study targets four representative GNBs (Geometrically Necessary Boundaries) in terms of their unified and quantitative evaluations based on the field theory of multiscale plasticity (FTMP). Discrete dislocation dynamics simulations on GNBs 2, 3, 4 and 7, whose details about the consisting dislocations have been experimentally identified and
Ihara, S., Hasebe, T.
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Toughening and Hardening Limited Zone of High-Strength Steel through Geometrically Necessary Dislocation When Exposed to Electropulsing. [PDF]
Materials (Basel), 2022 The enhancement of both low-temperature impact toughness and the hardness of a high strength steel heat-affected zone (HAZ) is investigated by using high-density electropulsing (EP).
Xiong Y, Li Z, Liu T.
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Quantifying geometrically necessary dislocation density during hot deformation in AA6082 Al alloy [PDF]
, 2021 Physically based constitutive equations incorporating the key microstructural mechanisms e.g. dislocations, grain size, etc, have been used widely to predict the stress-strain behaviour of alloys at plastic and viscoplastic conditions.
Zheng, Jing-Hua +9 more
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A finite element method to calculate geometrically necessary dislocation density: accounting for orientation discontinuities in polycrystals [PDF]
, 2022 Strain gradients have been used to link various microscale deformation phenomena to the mechanical response of a polycrystalline material, revealing sub-crystal deformation structures.
Collins, Dm +5 more
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Modeling of extra strengthening in gradient nanotwinned metals based on molecular dynamics
Frontiers in Materials, 2022 Gradient nanotwinned metals exhibit extra strengthening and work hardening behaviors, which have enormous potential for engineering applications. In this study, molecular dynamics method is performed for analyzing the effects of nanotwinned structure ...
Zailin Yang +6 more
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Formation of grains and dislocation structure of geometrically necessary boundaries [PDF]
Materials Science and Engineering: A, 2015 A continuum dislocation model of formation of grains whose boundaries have a non-vanishing thickness is proposed. For a single crystal deforming in simple shear the lamellar structure of grains with thin layers containing dislocations as the geometrically necessary boundaries turns out to be energetically preferable.
Koster, Michael, Le, Khanh Chau
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