EBSD pattern analysis beyond band detection

Abstract number
European Microscopy Congress 2020
Corresponding Email
[email protected]
PST.5 - Diffraction techniques and structural analysis
Dr Rene de Kloe (1), Matt Nowell (1)

Direct electron detection, EBSD, quantitative pattern analysis

Abstract text

EBSD analysis has mainly evolved around orientation results derived from the diffraction patterns and not so much on the patterns themselves. The patterns display the diffracted intensity of electrons that have interacted with a sample. For traditional mapping the use of the diffraction patterns has been limited to finding the positions of the bands through the Hough transform. The resulting band positions are then matched against the crystal structure of candidate phases to determine the orientation at each point in an EBSD map. This information is used to perform orientation imaging microscopy to visualize and quantify the microstructure under investigation.

Recently it has become more common to record all EBSD patterns during mapping. This allows off-line image processing to improve band detection and indexing. It also enables the use of additional information that is present in the patterns through correlation with dynamically simulated patterns. One application is dictionary indexing where experimental patterns are matched against a library of dynamically simulated templates for all possible orientations. This does not require prior identification of bands and allows successful orientation determination of extremely noisy patterns. Together with the introduction of direct electron detection for EBSD the information in recorded patterns can also be explored to investigate the effects of the travel path of the electrons through the sample. Dynamic simulations can be used to investigate the effects of electron energy on pattern appearance. In this presentation I will explore these additional types of EBSD pattern information.