Fig. 7: SEM surface and fracture observation.

For samples before and after hydrogen charging on (a) AD, (b) HT600, (c) HT 800 and (d) HT1200, scale bar is shown in d4.
For samples before and after hydrogen charging on (a) AD, (b) HT600, (c) HT 800 and (d) HT1200, scale bar is shown in d4.