Monash Centre for Electron Microscopy presents seminar ‘Novel Indexing Approaches for EBSD: Using the Complete Pattern’ presented by Prof Marc De Graef Director of the J. Earle and Mary Roberts Materials Characterization Facility (MCF), Carnegie Mellon University, USA.
Electron back-scatter diffraction (EBSD) has during the past 25 years become an indispensable characterization tool in both materials science and the earth sciences. While the vendor companies have created new and faster detector systems, the underlying commercial indexing algorithm has not undergone significant updates or improvements after the initial development years. The effectiveness of the Hough-based indexing approach depends on the signal strength of the Kikuchi bands with respect to the background signal, and this is the Achilles Heel of the commercial implementations: if bands cannot be detected, then the indexing algorithm fails. In this presentation, we will begin with a discussion of a forward model for the simulation of EBSD and related diffraction patterns. Then we introduce the basic principles of the dictionary indexing approach, as well as the recently introduced spherical indexing algorithm. We will illustrate the robustness of both approaches with respect to pattern noise and the ability to index overlapping patterns near grain boundaries. Along the way we discuss a series of examples on both materials and geological systems. We conclude with preliminary results of the use of convolutional neural networks to accelerate the dictionary indexing approach.
For more information please contact mcem@monash.edu or call +61 3 9905 5563
EBSD image by Will Davids from Sydney Microscopy and Microanalysis
