Monitoring Live or Stored EBSPs while collecting a map:
While acquiring or reanalysing EBSD data it is possible to view patterns as they are collected or from any acquired point on the map. To view the live patterns select the ‘Live’ tab and the patterns are shown below the map:
If fast data acquisition is underway the images are updated every half second. In the example, the solution of the pattern shown (Iron bcc) is shown in red (the colour of that phase). These patterns can be viewed with the solution overlaid.
To review stored patterns, either during or after acquisition switch to the ‘Stored’ tab, then select the point of interest on the map using the tool shown below:
The pattern from the cursor position on the map is then displayed - again the solution can be shown over the pattern.
This is a useful tool for reviewing the fit between the pattern and solution as data is collected. By checking the fit between pattern and solution it is possible to change the solver settings and optimise your results.
Identifying Phases while collecting a map:
In addition, while the system is acquiring maps, you can investigate particular areas or phases of interest, review pattern and data quality. This capability is valuable for looking at patterns from phases which did not solve, as shown below. In this example a multiphase material is examined, but some of the phases are not indexed - although the pattern quality is good. If the pattern from the selected point is not indexed there is no solution shown:
By switching to the 'Phase ID' navigator while the map is acquiring, simultaneous EBSD and EDS data from a single point can be extracted in the 'Acquire Data' step:
This extracted data can then be interrogated using the Phase ID navigator to identify the unknown phase. Firstly, the chemical signature is used to identify a list of candidate phases in the 'Search Phase' step. The elements to be included in the search are selected; usually all major elements identified in the spectrum would be included in the search. This returns a short list of ‘candidate phases’.
Next, in the 'Identify Phase' step, the EBSP is used to rank the possible candidate phases to find the correct solution. The solutions are listed with the Mean Angular Deviation (MAD) number as a measure of fit between the pattern and solution. The pattern and best solution is displayed for review.
The additional phase can then be added to the map as it is being acquired, or for reanalysis. Returning to the Map navigator, the final map can be viewed with all the phases correctly identified.