Fig. 1: Dislocation motion during hydrogen charging observed with Electron Channeling Contrast Imaging (ECCI).
From: Hydrogen can both move or pin dislocations in body-centered cubic metals
a The ECCI analysis of dislocations as a function of the hydrogen charging time up to 9 h. b, c Magnified images of the area marked by dotted rectangles in (a), showing before and after 1 h of hydrogen charging. d The pixel grayscale value plot showing the relative location of the dislocation in (b). e The dislocation activity in another sample, during three hours of hydrogen charging followed by 6 months of air aging. f, g Magnified images of the area marked by dotted rectangles in (e), showing before and after one hour of hydrogen charging. h The relative location of the dislocation in (g). Dotted yellow lines in (a, e) are reference lines manually placed near the mobile dislocation based on nearby grain boundaries, which remain stationary during hydrogen charging. They serve as guides to the eye to help visualize subtle dislocation motion across time-lapse images. Dislocations indicated by yellow arrows represent those in motion, while the green arrow denotes a dislocation disappearing from the surface. Note that the thicknesses of the samples for (a) and (e) are different.
