Effect of Lattice Parameters of Master Pattern on EBSD Indexing via Pattern Matching

The effects of the lattice parameter of the simulated master pattern and the EBSD pattern resolution for indexing of EBSD patterns via pattern matching (Spherical Indexing) were investigated using annealed austenitic steel.A larger deviation from the accurate lattice parameter in the master pattern resulted in a larger deviation from the true crystallographic orientation.Poorer EBSD pattern resolution resulted in a lower angular resolution, especially near the grain boundary, and increased kernel average misorientation (KAM) values.These results suggest that accurate lattice parameter and higher pattern resolution are required for Spherical Indexing to achieve a better angular resolution.Nevertheless, Spherical Indexing using a master pattern with a 15 % deviation from the accurate lattice parameter and EBSD patterns with a binning of 8x8 provided a better angular resolution than traditional indexing using the Hough transformation of EBSD patterns without binning (binning of 1x1).This indicates that Spherical Indexing is an excellent indexing procedure in terms of angular resolution, which is robust for the lattice parameter of the master pattern and EBSD pattern resolution.