journal article·2015-10

Assessment of geometrically necessary dislocation levels derived by 3D EBSD

P.J. Konijnenberg, S. Zaefferer, D. Raabe

Acta Materialia· Volume 99
Publisher page

Abstract

Abstract Existing alternatives for the calculation of geometrically necessary dislocation (GND) densities from orientation fields are discussed. Importantly, we highlight the role of reference frames and consider different sources of error. A well-controlled micro cantilever bending experiment on a copper bicrystal has been analyzed by 3-dimensional electron back scatter diffraction (3D EBSD). The GND density is determined experimentally by two different approaches and assessed theoretically, assuming a homogeneous bending of the cantilever. Experiment and theory agree very well. It is further shown that the deformation is accommodated mainly by GNDs, which carry and store lattice rotation, and not (only) by mobile dislocations that leave a crystal portion inspected, without lattice rotations. A detailed GND analysis reveals a local density minimum close to the grain boundary and a distinct difference in edge to screw ratios for both grains.
Source: openaire · Quality: candidate unverified · Source record ↗

Research context

OpenAlex topics: Microstructure and mechanical properties · Aluminum Alloy Microstructure Properties · Metal Forming Simulation Techniques

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

References (36)

Show source-provided references
1. Some geometrical relations in dislocated crystals10.1016/0001-6160(53)90054-6 ↗
2. Der fundamentale Zusammenhang zwischen Versetzungsdichte und Spannungsfunktionen10.1007/BF01375082 ↗
3. Allgemeine Kontinuumstheorie der Versetzungen und Eigenspannungen10.1007/BF00281393 ↗
4. Continuous distributions of dislocations: a new application of the methods of non-Riemannian geometry
5. Observation of lattice curvature near the interface of a deformed aluminium bicrystal10.1080/01418610008212038 ↗
6. Viewpoint:experimental recovery of geometrically necessary dislocation density in polycrystals10.1016/S1359-6462(02)00340-8 ↗
7. Analysis of local orientation gradients in deformed single crystals10.1016/j.ultramic.2004.11.016 ↗
8. Microstructure of individual grains in cold-rolled aluminium from orientation inhomogeneities resolved by electron backscattering diffraction10.1016/j.msea.2007.10.092 ↗
9. Resolving the geometrically necessary dislocation content by conventional electron backscattering diffraction10.1016/j.scriptamat.2008.01.050 ↗
10. 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 ↗
11. The weighted Burgers vector: a new quantity for constraining dislocation densities and types using electron backscatter diffraction on 2D sections through crystalline materials10.1111/j.1365-2818.2009.03136.x ↗
12. Estimations of bulk geometrically necessary dislocation density using high resolution EBSD10.1016/j.ultramic.2013.04.011 ↗
13. Elastic strain tensor mapping – extending the limits of EBSD analysis
14. Measurement of residual elastic strain and lattice rotations with high resolution electron backscatter diffraction10.1016/j.ultramic.2011.05.007 ↗
15. Bragg’s law diffraction simulations for electron backscatter diffraction analysis10.1016/j.ultramic.2009.04.007 ↗
16. Determination of elastic strain fields and geometrically necessary dislocation distributions near nanoindents using electron back scatter diffraction10.1080/14786430903304145 ↗
17. EBSD-based continuum dislocation microscopy10.1016/j.ijplas.2010.05.008 ↗
18. Evolution of dislocation density distributions in copper during tensile deformation10.1016/j.actamat.2013.08.027 ↗
19. Measurement of geometrically necessary dislocation density with high resolution electron backscatter diffraction: Effects of detector binning and step size10.1016/j.ultramic.2012.11.003 ↗
20. Estimation of the full Nye’s tensor and its gradients by micro-mechanical stereo-inference using EBSD dislocation microscopy10.1016/j.ijplas.2013.04.006 ↗
21. Quantification of dislocation structure heterogeneity in deformed polycrystals by EBSD10.1088/0965-0393/20/2/024007 ↗
22. The deformation of plastically non-homogeneous materials10.1080/14786437008238426 ↗
23. A microbend test method for measuring the plasticity length scale10.1016/S1359-6454(98)00153-0 ↗
24. The mechanical size effect as a mean-field breakdown phenomenon: Example of microscale single crystal beam bending10.1016/j.actamat.2009.11.031 ↗
25. Bending of single crystal microcantilever beams of cube orientation: Finite element model and experiments10.1016/j.jmps.2010.07.007 ↗
26. Mechanical and microstructural single-crystal Bauschinger effects: Observation of reversible plasticity in copper during bending10.1016/j.actamat.2010.07.023 ↗
27. Christian · 1975
28. Sutton · 1995
29. Crystallographic aspects of geometrically-necessary and statistically-stored dislocations10.1016/S1359-6454(99)00020-8 ↗
30. Orientation imaging microscopy: emerging and future applications10.1016/S0304-3991(96)00103-9 ↗
31. Experimental lower bounds on geometrically necessary dislocation density10.1016/j.ijplas.2010.03.009 ↗
32. 3D-orientation microscopy in a FIB SEM: A new dimension of microstructure characterisation
33. Image distortions in SEM and their influences on EBSD measurements10.1016/j.ultramic.2006.07.003 ↗
34. Angular precision of automated electron backscatter diffraction measurements
35. EBSD-based microscopy: Resolution of dislocation density
36. Morawiec · 2004