  Plastic deformation mechanisms have been investigated in the MAX phase
Ti2AlN. Nanoindentation has been used to induce plastic deformation in a single
grain, and a Transmission Electron Microscopy (TEM) lamella has been extracted
in cross section through the indent by using Focused Ion Beam (FIB) technique.
By combining TEM observations and automated crystal orientation mapping (ACOM),
highly misoriented domains (HMD) have been revealed below a nanoindentation
imprint. Thanks to a careful analysis of the relative crystal orientations
between these HMD, {11-22} and {11-21} deformation twins have been identified
for the first time in a MAX phase. Complex structures, involving secondary
twinning or different {11-22} twin variants have also been characterized.
