Electron Backscatter Diffraction Data (The Class EBSD)

This section describes the class EBSD and gives an overview over the functionality that MTEX offers to analyze EBSD data.

On this page ...
Class Description
Import of EBSD Data
Plotting EBSD Data
Modify EBSD Data
Calculate an ODF from EBSD Data
Simulate EBSD Data
Demo
Complete Function list

Class Description

The following mindmap might give a basic idea about EBSD data analyis in MTEX, with the ability of grain modelling for spatial data. It offers various way of interpreting individual orientation measurements, i.e. in terms of quantifying macro-,micro- and mesotexture.

Import of EBSD Data

The most comfortable way to import EBSD data into MTEX is to use the import wizard, which can be started by the command

import_wizard('ebsd')

If the dataset is in a format supported by MTEX, the import wizard generates a script which imports the data. More information about the import wizard and a list of supported file formats can be found ImportEBSDData.html,here. A typical script generated by the import wizard looks a follows.

cs = crystalSymmetry('m-3m','mineral','Fe');      % crystal symmetry

% file names
fname = fullfile(mtexDataPath,'EBSD','85_829grad_07_09_06.txt');

% load data
ebsd = loadEBSD(fname,'CS',cs,...
                'interface','generic','Bunge','ignorePhase',[0 2],...
                 'ColumnNames', { 'Phase' 'x' 'y' 'Euler 1' 'Euler 2' 'Euler 3'},...
                 'Columns', [2 3 4 5 6 7])
 
ebsd = EBSD  
 
 Phase  Orientations  Mineral       Color  Symmetry  Crystal reference frame
     1  48184 (100%)       Fe  light blue      m-3m                         
 
 Properties: x, y
 Scan unit : um
 

Plotting EBSD Data

EBSD data are plotted using the command EBSD.plot.html,plot. It assigns a color to each orientation and plots a map of these colors. There are several options to specify the way the colors are assigned.

oM = ipdfHSVOrientationMapping(ebsd);
plot(ebsd,oM.orientation2color(ebsd.orientations))
 
  Hint: You might want to use the point group
  "432" for colorcoding!
 

In order to understand the color coding one can plot the coloring of the corresponding inverse pole figure via

plot(oM)
hold on
plotIPDF(ebsd('Fe').orientations,xvector,'markerSize',3,'points',500,'marker','o','markerfacecolor','none','markeredgecolor','k')
hold off
  I'm plotting 500 random orientations out of 48184 given orientations

Modify EBSD Data

MTEX offers a lot of operations to analyze and manipulate EBSD data, e.g.

An exhausive introduction how to analyze and modify EBSD data can be found here

Calculate an ODF from EBSD Data

The command calcODF performs an ODF calculation from EBSD data using kernel density estimation EBSD data. For a precise explanation of the algorithm and the available options please look at here.

odf = calcODF(ebsd('Fe').orientations,'halfwidth',10*degree)
plotPDF(odf,Miller(1,0,0,odf.CS),'antipodal')
 
odf = ODF  
  crystal symmetry : Fe (m-3m)
  specimen symmetry: 1
 
  Portion specified by Fourier coefficients:
    degree: 28
    weight: 1
 

Simulate EBSD Data

Simulating EBSD data from a given ODF is useful to analyze the stability of the ODF estimation process. There is an example demonstrating how to determine the number of individual orientation measurements to estimate the ODF up to a given error. The MTEX command to simulate EBSD data is calcEBSD, e.g.

ori = calcOrientations(unimodalODF(orientation(idquaternion,cs)),500)
plotPDF(ori,Miller(1,0,0,cs),'antipodal','MarkerSize',3)
 
ori = orientation  
  size: 500 x 1
  crystal symmetry : Fe (m-3m)
  specimen symmetry: 1
 
  I'm plotting 208 random orientations out of 500 given orientations
  You can specify the the number points by the option "points".
  The option "all" ensures that all data are plotted

Demo

For a more exaustive description of the EBSD class have a look at the EBSD demo!

Complete Function list

AliginingEBSDDataAligning EBSD data to a reference frame
AnalyzeEBSDDataAnalyze EBSD Data
EBSD2odfODF Estimation from EBSD data
EBSDAnalysisEBSD Data Analysis
EBSDAnalysisIntroFirst Steps
EBSDBinghamBingham distribution and EBSD data
EBSDModifyDataModify EBSD Data
EBSDOrientationPlotsPlotting Individual Orientations
EBSDSharpPlotVisualizing EBSD data with sharp textures
EBSDSimulation_demoSimulating EBSD data
EBSDSpatialPlotsPlotting spatially indexed EBSD data
ImportEBSDDataImporting EBSD Data