journal article·2016-09Open access

Geometrically necessary dislocations favor the Taylor uniform deformation mode in ultra-fine-grained polycrystals

L.S. Toth, C.F. Gu, B. Beausir, J.J. Fundenberger, M. Hoffman

Acta Materialia· Volume 117

Abstract

Abstract The density of geometrically necessary dislocations (GND) obtained from the lattice curvature was studied in commercially pure copper up to extreme large strains (von Mises strain of 63). Its evolution shows an increase to a maximum at a strain of about 2, then decreases until reaching the stationary limiting stage of grain refinement at a von Mises strain of about 14. At the same time, the total dislocation density is also decreasing. It is shown that the variation in the GND density correlates with the difference between the correlated (first neighbor grains) and the non-correlated (random neighbor) misorientation angle distributions. The low quantity of GND at extreme large strains is a consequence of the near Taylor-type homogeneous behavior of the polycrystalline ultrafine-grained structure.
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Research context

OpenAlex topics: Microstructure and mechanical properties · Microstructure and Mechanical Properties of Steels · Metal Forming Simulation Techniques

SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.

References (39)

Show source-provided references
1. Deformation mode and plastic flow in ultrafine grained metals10.1016/j.msea.2005.06.035 ↗
2. Extreme grain refinement by severe plastic deformation: a wealth of challenging science10.1016/j.actamat.2012.10.038 ↗
3. Producing bulk ultrafine-grained materials by severe plastic deformation10.1007/s11837-006-0213-7 ↗
4. Bulk nanostructured materials from severe plastic deformation10.1016/S0079-6425(99)00007-9 ↗
5. The deformation of plastically non-homogeneous materials10.1080/14786437008238426 ↗
6. Geometrically necessary boundaries, incidental dislocation boundaries and geometrically necessary dislocations10.1016/S1359-6462(02)00358-5 ↗
7. Crystallite size distribution and dislocation structure determined by diffraction profile analysis: principles and practical application to cubic and hexagonal crystals10.1107/S0021889801003715 ↗
8. Electron back-scattering patterns – a new technique for obtaining crystallographic information in the scanning electron microscope10.1080/14786437308225827 ↗
9. Review – grain and subgrain characterisation by electron backscatter diffraction10.1023/A:1017973432592 ↗
10. Automated Crystal Orientation Mapping (ACOM) with a computer controlled TEM by interpreting transmission Kikuchi patterns10.4028/www.scientific.net/MSF.273-275.215 ↗
11. The determination of local texture by electron diffraction — a tutorial review10.1155/TSM.20.7 ↗
12. Polycrystal orientation maps from TEM10.1016/S0304-3991(02)00435-7 ↗
13. Automated crystal orientation and phase mapping in TEM10.1016/j.matchar.2014.08.010 ↗
14. Orientation mapping of nanostructured materials using transmission Kikuchi diffraction in the scanning electron microscope10.1016/j.ultramic.2012.06.004 ↗
15. Stage IV work-hardening related to misorientations in dislocation structures10.1016/j.msea.2003.11.088 ↗
16. Modeling of large strain hardening during grain refinement10.1016/j.scriptamat.2011.11.002 ↗
17. Orientation gradients and geometrically necessary dislocations in ultrafine grained dual-phase steels studied by 2D and 3D EBSD10.1016/j.msea.2010.01.004 ↗
18. Investigation of the indentation size effect through the measurement of the geometrically necessary dislocations beneath small indents of different depths using EBSD tomography10.1016/j.actamat.2008.09.039 ↗
19. Analysis of local orientation gradients in deformed single crystals
20. Determination of elastic strain fields and geometrically necessary dislocation distributions near nanoindents using electron back scatter diffraction10.1080/14786430903304145 ↗
21. A model of grain fragmentation based on lattice curvature10.1016/j.actamat.2009.11.020 ↗
22. A self-consistent approach of the large deformation polycrystal viscoplasticity10.1016/0001-6160(87)90297-5 ↗
23. A self-consistent anisotropic approach for the simulation of plastic-deformation and texture development of polycrystals – application to zirconium alloys10.1016/0956-7151(93)90130-K ↗
24. Tuning a self consistent viscoplastic model by finite element results, Part I: modelling10.1016/0956-7151(94)90324-7 ↗
25. New experimental insight into the mechasims of nanoplasticity10.1016/j.actamat.2013.08.032 ↗
26. Grain size dependent texture evolution in severely rolled pure copper10.1016/j.matchar.2015.02.003 ↗
27. Unexpected brass-type texture in rolling of ultrafine-grained copper10.1016/j.scriptamat.2014.08.012 ↗
28. Microstructure, texture and mechanical properties of aluminum processed by high pressure tube twisting10.1016/j.actamat.2012.04.035 ↗
29. Beausir · 2015
30. Gubicza · J. Alloys Compd. · 2009 · 483 · 27110.1016/j.jallcom.2008.07.200 ↗
31. 2nd paper on statistics associated with the random misorientation of cubes10.1093/biomet/45.1-2.229 ↗
32. Spatial correlation in grain misorientation distribution10.1016/j.actamat.2009.07.035 ↗
33. Effect of grain refinement by severe plastic deformation on the next-neighbour misorientation distribution10.1016/j.actamat.2010.08.036 ↗
34. Microstructure and strain in protrusions formed during severe plastic deformation of aluminum10.1016/j.matlet.2015.07.008 ↗
35. Microstructure, texture and mechanical properties of cyclic expansion-extrusion deformed pure copper10.1016/j.msea.2015.01.003 ↗
36. A method for making rapid surveys of woodlands by means of pairs of randomly selected trees10.2307/1932281 ↗
37. Axial stresses and texture development during the torsion testing of Al, Cu and Alpha-Fe10.1016/0001-6160(84)90187-1 ↗
38. Structure of Cu deformed by high pressure torsion10.1016/j.actamat.2004.09.043 ↗
39. A model of continuous dynamic recrystallization10.1016/S1359-6454(03)00078-8 ↗