Figure 6
Final verification with a synthetic polycrystal. The ROIs are shown as grey spheres. The wire-frame diagram in panel (a) represents the triple lines between the grains (Voronoi cells) coloured by grain ID. Panels (b) (σz = 0.00 Å), (c) (σz = 0.25 Å) and (e) (σz = 0.50 Å) display for all ROIs of the data set the disorientation to the individual true orientation of each ROI. The blue points display the disorientation (angle) as a function of the image difference and the signal contribution (ζ) from the grain with the highest signal contribution. The results confirm that fully automated indexing is possible as long as the positional noise remains lower than σz = 0.5 Å. For ROIs at grain boundaries and junctions it is already evident from (b) that the solution quality deteriorates systematically the more strongly the neighbouring grains mix signal contributions into the signature. Panel (d) shows exemplar cases of the signatures and the 3D geometry of ROIs in different relative locations to the grain boundary network (inside, boundary, triple line and quad junction). |