Azimuthal Projections: Data Rotation and Projection Switching in Real Time

2013 ◽  
Vol 19 (4) ◽  
pp. 950-958 ◽  
Author(s):  
Gert Nolze
Keyword(s):  
Real Time ◽  
Materials Science ◽  
Electron Backscatter Diffraction ◽  
Explicit Calculation ◽  
Orientation Data ◽  
Time Switching ◽  
Pole Figures ◽  
Backscatter Diffraction ◽  
Spherical Projection ◽  
Single Orientation

AbstractPole figures are often used to present crystal orientation data. The huge number of single orientation measurements acquired by electron backscatter diffraction (EBSD) poses a challenge for pole figure representation due to the large number of calculations required. This significantly reduces the speed at which the data may be rotated and affects the ability to switch between different projection types. In the present work, it will be shown that satisfactory representation of orientation data in different projection types can generally be achieved by an imaging of a spherical projection. With this approach, explicit calculation of the projections is no longer required, allowing for both real-time dataset rotation and real-time switching between all projection types relevant to materials science. The technique can be applied to any other directional property distribution, for example, not only for EBSD orientation presentation.

Defining the hematite topotaxial crystal growth in magnetite–hematite phase transformation

2020 ◽  
Vol 53 (4) ◽  
pp. 896-903
Author(s):  
Flávia Braga de Oliveira ◽  
Gilberto Álvares da Silva ◽  
Leonardo Martins Graça
Keyword(s):  
Electron Backscatter Diffraction ◽  
Inverse Pole Figure ◽  
Orientation Relationships ◽  
Transformation Matrices ◽  
Hematite Phase ◽  
Pole Figures ◽  
Magnetite Crystal ◽  
Diffraction Patterns ◽  
Backscatter Diffraction ◽  
Specific Orientation

Magnetite and hematite iron oxides are minerals of great economic and scientific importance. The oxidation of magnetite to hematite is characterized as a topotaxial reaction in which the crystallographic orientations of the hematite crystals are determined by the orientation of the magnetite crystals. Thus, the transformation between these minerals is described by specific orientation relationships, called topotaxial relationships. This study presents electron-backscatter diffraction analyses conducted on natural octahedral crystals of magnetite partially transformed into hematite. Inverse pole figure maps and pole figures were used to establish the topotaxial relationships between these phases. Transformation matrices were also applied to Euler angles to assess the diffraction patterns obtained and confirm the identified relationships. A new orientation condition resulting from the magnetite–hematite transformation was characterized, defined by the parallelism between the octahedral planes {111} of magnetite and rhombohedral planes \{10\bar {1}1\} of hematite. Moreover, there was a coincidence between one of the octahedral planes of magnetite and the basal {0001} plane of hematite, and between dodecahedral planes {110} of magnetite and prismatic planes \{11\bar {2}0\} of hematite. All these three orientation conditions are necessary and define a growth model for hematite crystals from a magnetite crystal. A new topotaxial relationship is also proposed: (111)Mag || (0001)Hem and (\bar {1}\bar {1}1)_{\rm Mag} || (10\bar {1}1)_{\rm Hem}.

Deformation Structures in a Duplex Stainless Steel

2018 ◽  
Vol 941 ◽  
pp. 176-181 ◽  
Author(s):  
Karin Yvell ◽  
Göran Engberg
Keyword(s):  
Electron Backscatter Diffraction ◽  
Texture Evolution ◽  
True Strain ◽  
Strain Curve ◽  
Tensile Tests ◽  
Uniaxial Tensile ◽  
Deformation Structure ◽  
Pole Figures ◽  
Two Phases ◽  
Backscatter Diffraction

The evolution of the deformation structure with strain has been studied using electron backscatter diffraction (EBSD). Samples from interrupted uniaxial tensile tests and from a cyclic tension/compression test were investigated. The evolution of low angle boundaries (LABs) was studied using boundary maps and by measuring the LAB density. From calculations of local misorientations, smaller orientation changes in the substructure can be illustrated. The different orientations developed with strain within a grain, due to operation of different slip systems in different parts of the grain, were studied using a misorientation profile showing substantial orientation changes after a true strain of 0.24. The texture evolution with increasing strain was followed by using inverse pole figures (IPFs). The observed substructure development in the ferritic and austenitic phases could be successfully correlated with the stress-strain curve from a tensile test. LABs were first observed in the different phases when the strain hardening rate changed in appearance indicating that cross slip started to operate as a significant dislocation recovery mechanism. The evolution of the deformation structure is concluded to occur in a similar manner in the austenitic and ferritic phases but with different texture evolution for the two phases.

scholarly journals Key Parameters to Promote Granularization of Lath-Like Bainite/Martensite in FeNiC Alloys during Isothermal Holding

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1808
Author(s):  
Meriem Ben Haj Slama ◽  
Nathalie Gey ◽  
Lionel Germain ◽  
Kangying Zhu ◽  
Sébastien Allain
Keyword(s):  
Electron Backscatter Diffraction ◽  
Isothermal Holding ◽  
Lower Bainite ◽  
Ferrite Matrix ◽  
Granular Bainite ◽  
Orientation Data ◽  
Isothermal Ageing ◽  
The Stability ◽  
Backscatter Diffraction

The stability of lath-like microstructures during low-temperature isothermal ageing was analyzed in a Fe5Ni0.33C (in wt %) steel. The microstructures were characterized using Scanning Electron Microscopy (SEM) coupled with Electron Backscatter Diffraction (EBSD). Advanced orientation data processing was applied to quantify the hierarchical and multiscale organization of crystallographic variants subdividing Prior Austenite Grains (PAG) into packets/blocks/sub-blocks. The result shows that ferrite laths of martensite or lower bainite are stable, whatever the ageing temperature (up to 380 °C). On the contrary, a granularization process is triggered when microstructures contain a fraction of upper bainite. This metallurgical evolution corresponds to a rapid and significant change of the ferrite matrix involving a disappearance of 60° disoriented blocks. The phenomenon affects in turn the mechanical properties. The final microstructures obtained after isothermal holding look like granular bainite, which raises some questions about the classification of bainite.

Local Texture and Electromigration in Fine Line Microelectronic Aluminum Metallization

1994 ◽  
Vol 343 ◽  
Author(s):  
J. L. Hurd ◽  
K. P. Rodbell ◽  
D. B. Knorr ◽  
N. L. Koligman
Keyword(s):  
Electron Backscatter Diffraction ◽  
Fiber Texture ◽  
X Ray Diffraction ◽  
Aluminum Films ◽  
Pole Figures ◽  
Grain Orientations ◽  
Aluminum Metallization ◽  
Backscatter Diffraction ◽  
Relationship Of ◽  
The Relationship

ABSTRACTAluminum films 1 μm thick were deposited on oxidized silicon by sputtering and partially ionized beam evaporation to vary the crystallographic texture. These films were patterned into lines and subsequently annealed at 400 °C for 1 h. A strong correlation between the electromigration behavior and the blanket film texture (X-ray diffraction (XRD) / pole figures) has been reported previously for these films. In this work, an Electron Backscatter Diffraction (EBSD) a.k.a. Backscatter Kikuchi Diffraction (BKD) technique was employed using a scanning electron microscope (SEM) to interrogate individual grain orientations. BKD pole figures were acquired for lines ≥0.3 μm wide and for blanket (pad) regions. Identical, inverse pole figures were found for blanket films measured using both XRD and BKD (pads). Furthermore, the BKD (111) fiber texture shows a line width dependency, with narrow lines having a slightly improved texture over blanket (pad) regions. Local grain orientations were investigated near and within electromigration testing sites with characteristic void and hillock morphologies. The relationship of neighboring grain orientations to electromigration damage is shown.

A Review of Strain Analysis Using Electron Backscatter Diffraction

2011 ◽  
Vol 17 (3) ◽  
pp. 316-329 ◽  
Author(s):  
Stuart I. Wright ◽  
Matthew M. Nowell ◽  
David P. Field
Keyword(s):  
Plastic Strain ◽  
Materials Science ◽  
Electron Backscatter Diffraction ◽  
Strain Analysis ◽  
Current State ◽  
Mapping Parameters ◽  
Submicron Scale ◽  
Electron Backscatter ◽  
Ebsd Technique ◽  
Backscatter Diffraction

AbstractSince the automation of the electron backscatter diffraction (EBSD) technique, EBSD systems have become commonplace in microscopy facilities within materials science and geology research laboratories around the world. The acceptance of the technique is primarily due to the capability of EBSD to aid the research scientist in understanding the crystallographic aspects of microstructure. There has been considerable interest in using EBSD to quantify strain at the submicron scale. To apply EBSD to the characterization of strain, it is important to understand what is practically possible and the underlying assumptions and limitations. This work reviews the current state of technology in terms of strain analysis using EBSD. First, the effects of both elastic and plastic strain on individual EBSD patterns will be considered. Second, the use of EBSD maps for characterizing plastic strain will be explored. Both the potential of the technique and its limitations will be discussed along with the sensitivity of various calculation and mapping parameters.

Denoising of crystal orientation maps

2019 ◽  
Vol 52 (5) ◽  
pp. 984-996 ◽  
Author(s):  
R. Hielscher ◽  
C. B. Silbermann ◽  
E. Schmidl ◽  
Joern Ihlemann
Keyword(s):  
Variational Methods ◽  
Crystal Orientation ◽  
Electron Backscatter Diffraction ◽  
Sliding Window ◽  
Orientation Data ◽  
Kernel Average Misorientation ◽  
Orientation Maps ◽  
Electron Backscatter ◽  
Backscatter Diffraction

This paper compares several well known sliding-window methods for denoising crystal orientation data with variational methods adapted from mathematical image analysis. The variational methods turn out to be much more powerful in terms of preserving low-angle grain boundaries and filling holes of non-indexed orientations. The effect of denoising on the determination of the kernel average misorientation and the geometrically necessary dislocation density is also discussed. Synthetic as well as experimental data are considered for this comparison. The examples demonstrate that variational denoising techniques are capable of significantly improving the accuracy of properties derived from electron backscatter diffraction maps.

Plagioclase twins in a basalt: an electron backscatter diffraction study

2016 ◽  
Vol 49 (6) ◽  
pp. 2145-2154 ◽  
Author(s):  
Chang Xu ◽  
Shan-Rong Zhao ◽  
Chuan Li ◽  
Xu He
Keyword(s):  
Alkali Basalt ◽  
Microprobe Analysis ◽  
Electron Backscatter Diffraction ◽  
Subsequent Transformation ◽  
Pole Figures ◽  
Growth History ◽  
Electron Backscatter ◽  
Crystallization Conditions ◽  
Backscatter Diffraction ◽  
The Relationship

Twins in plagioclase, which are abundant in rocks, have important implications for the growth history and subsequent transformation. There are many twin laws in plagioclase and some of them are difficult to identify. This paper presents an electron backscatter diffraction (EBSD) analysis combined with electron microprobe analysis of plagioclase twinning in the Niutoushan alkali basalt. Theoretical pole figures of 12 different twin laws for plagioclase were generated. By comparing the pole figures obtained from EBSD with the theoretical ones, 11 twin laws have been identified in the alkali basalt, and their frequency has also been determined: Albite (28%), Carlsbad (25%), Albite–Carlsbad (34%), Pericline (3%), Ala (2%), Manebach (1%), Albite–Ala (1%), Prism {110} (2%), Prism {1\bar 10} (1%), Prism {130} (1%) and Prism {1\bar 30} (1%). All the plagioclase twins in the alkali basalt are growth twins. The anorthite content of the plagioclase has a negative correlation with the frequency of the Pericline and Albite twin laws but a positive correlation with the frequency of all the other twin laws, which is consistent with previous results. The theoretical pole figures of twin laws for plagioclase introduced in this paper can be applied to investigating plagioclase twin laws in all plagioclase-bearing rocks, and the relationship between twin pattern and crystallization conditions of the rocks can be established.

Crystallographic Features of Low-Carbon Bainite Formed under Non-Isothermal Conditions

2013 ◽  
Vol 762 ◽  
pp. 110-115 ◽  
Author(s):  
S.N. Panpurin ◽  
Nikolay Y. Zolotorevsky ◽  
Yuri F. Titovets ◽  
A.A. Zisman ◽  
E.I. Khlusova
Keyword(s):  
Cooling Rate ◽  
Electron Backscatter Diffraction ◽  
Bainitic Ferrite ◽  
Low Carbon ◽  
Austenite Grain Size ◽  
Orientation Data ◽  
Austenite Grain ◽  
Low Carbon Bainite ◽  
Backscatter Diffraction ◽  
Parent Austenite

The effects of cooling rate and austenite structure on bainite formation was investigated by means of electron backscatter diffraction analysis and processing of obtained orientation data. Variant pairing tendency of bainitic ferrite was found to depend on the austenite grain size, austenite plastic deformation and cooling rate. In the bainite formed at low cooling rate the variant pairs having the same Bain axis correspondence are more frequent, while at high cooling rate the variant pairs having the same parallel correspondence of close-packed planes are formed side by side preferably. At the same time, these features are influenced significantly by structural state of parent austenite.

ECCI, EBSD and EPSC characterization of rhombohedral twinning in polycrystalline α-alumina deformed in a D-DIA apparatus

2017 ◽  
Vol 50 (6) ◽  
pp. 1691-1704 ◽  
Author(s):  
Shirin Kaboli ◽  
Pamela C. Burnley
Keyword(s):  
Electron Backscatter Diffraction ◽  
X Ray Diffraction ◽  
Contrast Imaging ◽  
Twin Boundaries ◽  
Experimental Conditions ◽  
Polycrystalline Alumina ◽  
Orientation Mapping ◽  
Pole Figures ◽  
Backscatter Diffraction ◽  
Critical Resolved Shear Stress

Rhombohedral twinning in alumina (aluminium oxide, α-Al2O3) is an important mechanism for plastic deformation under high-temperature–pressure conditions. Rhombohedral twins in a polycrystalline alumina sample deformed in a D-DIA apparatus at 965 K and 4.48 GPa have been characterized. Three classes of grains were imaged, containing single, double and mosaic twins, using electron channeling contrast imaging (ECCI) in a field emission scanning electron microscope. These twinned grains were analyzed using electron backscatter diffraction (EBSD). The methodology for twin identification presented here is based on comparison of theoretical pole figures for a rhombohedral twin with experimental pole figures obtained with EBSD crystal orientation mapping. An 85°〈02{\overline 2}1〉 angle–axis pair of misorientation was identified for rhombohedral twin boundaries in alumina, which can be readily used in EBSD post-processing software to identify the twin boundaries in EBSD maps and distinguish the rhombohedral twins from basal twins. Elastic plastic self-consistent (EPSC) modeling was then used to model the synchrotron X-ray diffraction data from the D-DIA experiments utilizing the rhombohedral twinning law. From these EPSC models, a critical resolved shear stress of 0.25 GPa was obtained for rhombohedral twinning under the above experimental conditions, which is internally consistent with the value estimated from the applied load and Schmid factors determined by EBSD analysis.

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