Deformation microstructure developed by nanoindentation of a MAX Phase Ti₂AlC

Deformation microstructure that developed during nanoindentation of a MAX phase Ti₂AlC was characterized by the scanning probe microscopy and the transmission electron microscopy. To investigate the plastic anisotropy, nanoindentation measurements were made on grains with the normal parallel to h3362 i, h0001i, and h1120 i. The basal slip, f0001gh1120 i, was found to be predominant as the deformation mechanism for all the indentation directions. It was also indicated that, upon nanoindentation along h0001i and h1120 i, non-basal slips occurred underneath the indenter. The slip system of the non-basal dislocations was identified to be ð12 16 Þ½1211 by analyzing the dislocations. Furthermore, fine-scaled kink-bands were found to form underneath the residual impression. The formation of the kink-band was accompanied by delamination, i.e., micro-cracking along the basal plane, suggesting that the delamination plays an important role for kink-band formation in Ti₂AlC.