Atomic force microscopy and transmission electron microscopy identification of deformation twinning in the Cr2AlC MAX phase
Résumé
Elementary deformation mechanisms have been investigated in a single-crystalline Cr2AlC MAX phase. Plastic
deformation has been induced at room temperature by spherical nanoindentation, with a crystal orientation
chosen to minimize basal slip and to promote local crystal reorientation. The combination of Atomic Force
Microscopy (AFM) surface observation, Transmission Electron Microscopy (TEM) characterization and Auto-
mated Crystal Orientation Mapping (ACOM) in a same region has provided a full 3D characterization of the
deformation microstructure. Localized and isolated deformation twins have been identified below the indents.
The whole microstructure consists in interactions between dislocations and {1124} twin variants. The TEM
analysis also revealed activation of a 1
3 〈1120〉{1103} slip system never reported before in a MAX phase.