Advances in Transmission Electron Microscopy: Self Healing or is Prevention Better than Cure?

In the field of transmission electron microscopy fundamental and practical reasons still remain that hamper a straightforward correlation between microscopic structural information and self healing mechanisms in materials. We argue that one should focus in particular on in situ rather than on postmortem observations of the microstructure. In this contribution this viewpoint has been exemplified with in situ TEM nanoindentation and in situ straining studies at elevated temperatures of metallic systems that are strengthened by either solid solution or antiphase boundaries in intermetallic compounds. It is concluded that recent advances in in situ transmission electron microscopy can provide new insights in the interaction between dislocations and interfaces that are relevant for self healing mechanisms in metallic systems.