Electron backscatter diffraction: Difference between revisions

Revision as of 23:45, 30 December 2023

Revision as of 18:30, 5 January 2024

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EBSD is conducted using an SEM equipped with an EBSD detector containing at least a phosphor screen, compact lens and low-light [[Charge-coupled device]] (CCD) or Complementary metal–oxide–semiconductor (CMOS) camera. {{As of|2023|09}}, commercially available EBSD systems typically come with one of two different CCD cameras: for fast measurements, the CCD chip has a native resolution of 640×480 pixels; for slower, and more sensitive measurements, the CCD chip resolution can go up to 1600×1200 pixels.<ref name=":19" /><ref name=":0" />

The biggest advantage of the high-resolution detectors is their higher sensitivity, and therefore the information within each diffraction pattern can be analysed in more detail. For texture and orientation measurements, the diffraction patterns are [[Pixel binning|binned]] to reduce their size and computational times. Modern CCD-based EBSD systems can index patterns at a speed of up to 1800 patterns/second. This enables rapid and rich microstructural maps to be generated.<ref name=":20" /><ref name=":15">{{Cite journal |last1=Britton |first1=T. B. |last2=Jiang |first2=J. |last3=Guo |first3=Y. |last4=Vilalta-Clemente |first4=A. |last5=Wallis |first5=D. |last6=Hansen |first6=L. N. |last7=Winkelmann |first7=A. |last8=Wilkinson |first8=A. J. |date=2016 |title=Tutorial: Crystal orientations and EBSD — Or which way is up? |journal=Materials Characterization |volume=117 |pages=113–126 |doi=10.1016/j.matchar.2016.04.008 |s2cid=138070296|doi-access=free |hdl=10044/1/31250 |hdl-access=free }}</ref>

=== Sample preparation ===

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The use of simulated reference patterns for absolute strain measurement is still an active area of research<ref name=":22">{{Cite journal |last1=Winkelmann |first1=Aimo |last2=Trager-Cowan |first2=Carol |last3=Sweeney |first3=Francis |last4=Day |first4=Austin P. |last5=Parbrook |first5=Peter |date=2007 |title=Many-beam dynamical simulation of electron backscatter diffraction patterns |journal=Ultramicroscopy |volume=107 |issue=4 |pages=414–421 |doi=10.1016/j.ultramic.2006.10.006 |pmid=17126489}}</ref><ref>{{Cite journal |last1=Kacher |first1=Josh |last2=Landon |first2=Colin |last3=Adams |first3=Brent L. |last4=Fullwood |first4=David |date=2009-08-01 |title=Bragg's Law diffraction simulations for electron backscatter diffraction analysis |journal=Ultramicroscopy |volume=109 |issue=9 |pages=1148–1156 |doi=10.1016/j.ultramic.2009.04.007 |pmid=19520512}}</ref><ref>{{Cite journal |last1=Winkelmann |first1=A |last2=Nolze |first2=G |last3=Vos |first3=M |last4=Salvat-Pujol |first4=F |last5=Werner |first5=W S M |date=2016 |title=Physics-based simulation models for EBSD: advances and challenges |journal=IOP Conference Series: Materials Science and Engineering |volume=109 |issue=1 |pages=012018 |doi=10.1088/1757-899x/109/1/012018 |arxiv=1505.07982 |bibcode=2016MS&E..109a2018W |s2cid=38586851}}</ref><ref>{{Cite journal |last1=Alkorta |first1=Jon |last2=Marteleur |first2=Matthieu |last3=Jacques |first3=Pascal J. |date=2017 |title=Improved simulation based HR-EBSD procedure using image gradient based DIC techniques |journal=Ultramicroscopy |volume=182 |pages=17–27 |doi=10.1016/j.ultramic.2017.06.015 |pmid=28644960 }}</ref><ref>{{Cite journal |last1=Winkelmann |first1=Aimo |last2=Nolze |first2=Gert |last3=Cios |first3=Grzegorz |last4=Tokarski |first4=Tomasz |last5=Bała |first5=Piotr |last6=Hourahine |first6=Ben |last7=Trager‐Cowan |first7=Carol |date=November 2021 |title=Kikuchi pattern simulations of backscattered and transmitted electrons |journal=Journal of Microscopy |volume=284 |issue=2 |pages=157–184 |doi=10.1111/jmi.13051 |pmid=34275156 |s2cid=236091618 |url=https://strathprints.strath.ac.uk/78647/1/Winkelmann_etal_JM_2021_Kikuchi_pattern_simulations_of_backscattered_and_transmitted.pdf |access-date=20 March 2023 |archive-date=25 March 2023 |archive-url=https://web.archive.org/web/20230325200434/https://strathprints.strath.ac.uk/78647/1/Winkelmann_etal_JM_2021_Kikuchi_pattern_simulations_of_backscattered_and_transmitted.pdf |url-status=live }}</ref><ref>{{Cite journal |last=Winkelmann |first=A. |date= 2010 |title=Principles of depth-resolved Kikuchi pattern simulation for electron backscatter diffraction: KIKUCHI PATTERN SIMULATION FOR EBSD |journal=Journal of Microscopy |volume=239 |issue=1 |pages=32–45 |doi=10.1111/j.1365-2818.2009.03353.x |pmid=20579267 |s2cid=23590722}}</ref><ref>{{Cite journal |last1=Vermeij |first1=Tijmen |last2=De Graef |first2=Marc |last3=Hoefnagels |first3=Johan |date=2019-03-15 |title=Demonstrating the potential of accurate absolute cross-grain stress and orientation correlation using electron backscatter diffraction |journal=Scripta Materialia |volume=162 |pages=266–271 |doi=10.1016/j.scriptamat.2018.11.030 |arxiv=1807.03908 |s2cid=54575778 }}</ref><ref name="Angus J 2019">{{Cite journal |last1=Tanaka |first1=Tomohito |last2=Wilkinson |first2=Angus J. |date=2019-07-01 |title=Pattern matching analysis of electron backscatter diffraction patterns for pattern centre, crystal orientation and absolute elastic strain determination – accuracy and precision assessment |journal=Ultramicroscopy |volume=202 |pages=87–99 |doi=10.1016/j.ultramic.2019.04.006 |pmid=31005023 |arxiv=1904.06891 |s2cid=119294636 }}</ref> and scrutiny<ref name=":8" /><ref name="Angus J 2019"/><ref name="Brent L 2010">{{Cite journal |last1=Kacher |first1=Josh |last2=Basinger |first2=Jay |last3=Adams |first3=Brent L. |last4=Fullwood |first4=David T. |date=2010-06-01 |title=Reply to comment by Maurice et al. in response to "Bragg's Law Diffraction Simulations for Electron Backscatter Diffraction Analysis" |journal=Ultramicroscopy |volume=110 |issue=7 |pages=760–762 |doi=10.1016/j.ultramic.2010.02.004 |pmid=20189305 }}</ref><ref>{{Cite journal |last1=Britton |first1=T. B. |last2=Maurice |first2=C. |last3=Fortunier |first3=R. |last4=Driver |first4=J. H. |last5=Day |first5=A. P. |last6=Meaden |first6=G. |last7=Dingley |first7=D. J. |last8=Mingard |first8=K. |last9=Wilkinson |first9=A. J. |date=2010 |title=Factors affecting the accuracy of high resolution electron backscatter diffraction when using simulated patterns |journal=Ultramicroscopy |volume=110 |issue=12 |pages=1443–1453 |doi=10.1016/j.ultramic.2010.08.001 |pmid=20888125 }}</ref><ref>{{Cite journal |last=Alkorta |first=Jon |date=2013-08-01 |title=Limits of simulation based high resolution EBSD |journal=Ultramicroscopy |volume=131 |pages=33–38 |doi=10.1016/j.ultramic.2013.03.020 |pmid=23676453 }}</ref><ref>{{Cite journal |last1=Jackson |first1=Brian E. |last2=Christensen |first2=Jordan J. |last3=Singh |first3=Saransh |last4=De Graef |first4=Marc |last5=Fullwood |first5=David T. |last6=Homer |first6=Eric R. |last7=Wagoner |first7=Robert H. |date=August 2016 |title=Performance of Dynamically Simulated Reference Patterns for Cross-Correlation Electron Backscatter Diffraction |journal=Microscopy and Microanalysis |volume=22 |issue=4 |pages=789–802 |doi=10.1017/S143192761601148X |pmid=27509538 |bibcode=2016MiMic..22..789J |s2cid=24482631}}</ref> as difficulties arise from the variation of inelastic electron scattering with depth which limits the accuracy of dynamical diffraction simulation models, and imprecise determination of the pattern centre which leads to phantom strain components which cancel out when using experimentally acquired reference patterns. Other methods assumed that absolute strain at EBSP₀ can be determined using [[crystal plasticity]] finite-element (CPFE) simulations, which then can be then combined with the HR-EBSD data (e.g., using linear ‘top-up’ method<ref>{{Cite journal |last1=Zhang |first1=Tiantian |last2=Collins |first2=David M. |last3=Dunne |first3=Fionn P. E. |last4=Shollock |first4=Barbara A.|author4-link=Barbara Shollock |date=2014|title=Crystal plasticity and high-resolution electron backscatter diffraction analysis of full-field polycrystal Ni superalloy strains and rotations under thermal loading |journal=Acta Materialia |volume=80 |pages=25–38 |doi=10.1016/j.actamat.2014.07.036 |hdl=10044/1/25979 |hdl-access=free }}</ref><ref>{{Cite journal |last1=Guo |first1=Yi |last2=Zong |first2=Cui |last3=Britton |first3=T. B. |date=2021 |title=Development of local plasticity around voids during tensile deformation |journal=Materials Science and Engineering: A |volume=814 |pages=141227 |doi=10.1016/j.msea.2021.141227 |arxiv=2007.11890 |s2cid=234850241 }}</ref> or displacement integration<ref name=":33" />) to calculate the absolute lattice distortions.

In addition, GND density estimation is nominally insensitive to (or negligibly dependent upon<ref>{{Cite journal |last1=Jiang |first1=J. |last2=Britton |first2=T. B. |last3=Wilkinson |first3=A. J. |date=2013-11-01 |title=Evolution of dislocation density distributions in copper during tensile deformation |journal=Acta Materialia |volume=61 |issue=19 |pages=7227–7239 |doi=10.1016/j.actamat.2013.08.027 |bibcode=2013AcMat..61.7227J |doi-access=free }}</ref><ref>{{Cite journal |last1=Britton |first1=T B |last2=Hickey |first2=J L R |date= 2018 |title=Understanding deformation with high angular resolution electron backscatter diffraction (HR-EBSD) |journal=IOP Conference Series: Materials Science and Engineering |volume=304 |issue=1 |pages=012003 |doi=10.1088/1757-899x/304/1/012003 |bibcode=2018MS&E..304a2003B |s2cid=54529072 |arxiv=1710.00728 }}</ref>) EBSP₀ choice, as only neighbour point-to-point differences in the lattice rotation maps are used for GND density calculation.<ref>{{Cite journal |last1=Kalácska |first1=Szilvia |last2=Dankházi |first2=Zoltán |last3=Zilahi |first3=Gyula |last4=Maeder |first4=Xavier |last5=Michler |first5=Johann |last6=Ispánovity |first6=Péter Dusán |last7=Groma |first7=István |date=2020 |title=Investigation of geometrically necessary dislocation structures in compressed Cu micropillars by 3-dimensional HR-EBSD |journal=Materials Science and Engineering: A |volume=770 |pages=138499 |doi=10.1016/j.msea.2019.138499 |s2cid=189928469 |url=https://bib-pubdb1.desy.de/record/426593 |access-date=20 March 2023 |archive-date=17 July 2020 |archive-url=https://web.archive.org/web/20200717095713/http://bib-pubdb1.desy.de/record/426593 |url-status=live |arxiv=1906.06980 }}</ref><ref>{{Cite journal |last1=Wallis |first1=David |last2=Hansen |first2=Lars N. |last3=Britton |first3=T. Ben |last4=Wilkinson |first4=Angus J. |date= 2017 |title=Dislocation Interactions in Olivine Revealed by HR-EBSD: Dislocation Interactions in Olivine |journal=Journal of Geophysical Research: Solid Earth |volume=122 |issue=10 |pages=7659–7678 |doi=10.1002/2017JB014513|hdl=10044/1/50615 |s2cid=134570945 |hdl-access=free }}</ref> However, this assumes that the absolute lattice distortion of EBSP₀ only changes the relative lattice rotation map components by a constant value which vanishes during derivative operations, i.e., lattice distortion distribution is insensitive to EBSP₀ choice.<ref name=":9" /><ref name=":10">{{Cite journal |last1=Koko |first1=Abdalrhaman |last2=Tong |first2=Vivian |last3=Wilkinson |first3=Angus J. |author-link3=Angus Wilkinson |last4=Marrow |first4=T. James |author-link4=James Marrow |date=2023 |title=An iterative method for reference pattern selection in high-resolution electron backscatter diffraction (HR-EBSD) |journal=Ultramicroscopy |volume=248 |pages=113705 |arxiv=2206.10242 |doi=10.1016/j.ultramic.2023.113705 |pmid=36871367 |s2cid=249889699}}{{Creative Commons text attribution notice|cc=by4|from this source=yes}}</ref>

=== Selecting a reference pattern ===

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* Selecting an EBSP₀ after examining the empirical relationship between the cross-correlation parameter and angular error, used in an iterative algorithm to identify the optimal reference pattern that maximises the precision of HR-EBSD.<ref name=":10" />

These criteria assume these parameters can indicate the strain conditions at the reference point, which can produce an [[Accuracy and precision|accurate]] measurements of up to 3.2×10⁻⁴ elastic strain.<ref name=":7" /> However, experimental measurements point to the inaccuracy of HR-EBSD in determining the out-of-plane shear strain components distribution and magnitude.<ref>{{Cite journal |last1=McLean |first1=Mark J. |last2=Osborn |first2=William A. |date=2018|title=In-situ elastic strain mapping during micromechanical testing using EBSD |journal=Ultramicroscopy |volume=185 |pages=21–26 |doi=10.1016/j.ultramic.2017.11.007 |pmid=29161620 }}</ref><ref name=":44">{{Cite journal |last1=Yu |first1=Hongbing |last2=Liu |first2=Junliang |last3=Karamched |first3=Phani |last4=Wilkinson |first4=Angus J. |last5=Hofmann |first5=Felix |date=2019 |title=Mapping the full lattice strain tensor of a single dislocation by high angular resolution transmission Kikuchi diffraction (HR-TKD) |journal=Scripta Materialia |volume=164 |pages=36–41 |doi=10.1016/j.scriptamat.2018.12.039 |s2cid=119075799|doi-access=free |arxiv=1808.10055 }}</ref>

== Applications ==