Ion irradiation induced softening in Cr2AlC MAX phase

Abstract

MAX phases have exhibited excellent irradiation resistance regarding structure stability, but limited knowledge is available on the irradiation induced change in the mechanical performance of MAX phases. In this work, Cr2AlC single crystal samples were irradiated with 6 MeV C ions, and smaples’ mechanical properties were measured by micropillar compression test and nanoindentation technique. After irradiation, new slip traces are activated, which means the deformation behavior changed by irradiation. More important is that both the yield strength and Young’s modulus decrease gradually with the increasing irradiation doses up to 0.098 dpa, suggesting a significant radiation softening effect but not the radiation hardening effect which is very popular in other materials. This radiation softening effect is possible the result of the irradiation-induecd vacancies, which is supported by the DFT calculation. These results indicate that MAX phases like Cr2AlC have an excellent irradiation tolerance regarding mechanical properties and is a new class of promising candidate material for the advanced nuclear systems.