In Situ TEM and Computer-Aided Analysis of Individual Dislocation Motion Through a Cantor Alloy at Room and Liquid Nitrogen Temperature

FCC high entropy alloys from the Cantor family exhibit a great combination of toughness and ductility, especially at low temperature. To gain insight about the dislocation-based mechanisms at the origin of these properties, in situ TEM straining experiments have been performed at room and liquid nitrogen temperature. Both perfect dislocation and twinning activities have been observed, and linked to crystallographic orientations rather than a level of strain or stress. In addition, individual dislocations, taken as probe of the HEA distorted lattice have been followed using machine learning algorithms to detect possible chemical orders. This approach also helped quantifying the obstacle strength seen by the moving dislocations. The possible nature of such hardening origin of this class of alloy will be discussed.