Self‐Healing Phenomena in Metals

In comparison to other materials, in metals and metallic systems self‐healing of cracks and crack‐initiating defects is difficult to achieve due to the fact the solute atoms that act as healing agents are relatively small and generally have a relatively low mobility at the prevailing operating temperatures. In this review, the scientifically most interesting and industrially most promising approaches to self‐healing metals are presented and discussed. The various approaches are separated in autonomous healing methods based on an intrinsic (solid‐state diffusion) mechanism and assisted healing methods that need an external intervention. Some promising routes are identified while in other cases the approach has too many intrinsic limitations. Recently, a number of computational studies using molecular dynamics and finite element modeling have been performed to analyze the self‐healing potential of metal systems as a function of the imposed conditions and to guide the further development of this family of self‐healing materials.