Frank partial dislocation in Ti2AlC-MAX phase induced by matrix-Cu diffusion

Abstract

The control of complex nanostructures is one of the most promising strategy for designing tailored property materials. Ti2AlC, as nanolayered ternary materials combining both ceramics and metals properties, could efficiently reinforce metal matrix composite by its decomposition into nano-Ti2C particles. However, the comprehensive description of the diffusion mechanisms of Cu element into Ti2AlC during its decomposition has not yet been revealed. Herein, we report detailed characterizations of Cu and Ti2AlC interlayers by means of high-resolution electron microscopy and atomic-scale simulations. In particular, we report the formation of Ti2AlxCuyC solid solutions. Furthermore, we demonstrate the formation of Ti2C platelets and evidenced Frank partial dislocations that are not expected to be found in such material. Impacts of such defects are discussed in the framework of mechanical behavior.