POSITION-DEPENDENT MECHANICAL PROPERTIES OF GRAPHENE IN AlCrFeCuNi HIGH-ENTROPY ALLOY DURING NANOINDENTATION

This study investigates the nanoindentation behavior of pure AlCrFeCuNi high-entropy alloy (HEA) and AlCrFeCuNi HEA/graphene composites through molecular dynamics simulations, with an emphasis on the effect of graphene embedding depth. Compared to the pure AlCrFeCuNi HEA, AlCrFeCuNi HEA/ graphene composites exhibit significantly improved mechanical response when graphene is positioned near the surface. Specifically, both the indentation load and contact pressure increase, and the measured hardness values are significantly higher. As the embedding depth increases from 10 Å to 60 Å, the strengthening effect diminishes, and the hardness of the composite approaches that of the pure AlCrFeCuNi HEA. Analysis of shear strain and dislocation evolution reveals that the embedded graphene layer effectively suppresses the propagation of plastic deformation, acting as a mechanical barrier. The total dislocation length decreases with deeper graphene placement, confirming its role in limiting subsurface damage.