Probing the nanoscratching behavior of amorphous-crystalline dual-phase high entropy alloys nano-laminates with different crystalline orientations

The crystalline-amorphous (C-A) structure has been widely reported as an effective strategy to enhance the properties of metallic materials. In this spirit, the molecular dynamics simulations are performed to investigate the effect of crystalline orientation and the position of crystalline and amorphous layers on the wear properties and microstructure evolution of dual-phase CoCrFeNiMn HEA nano-laminates under scratching. The results demonstrate that crystalline orientation significantly affects both wear properties and plastic deformation in crystalline/amorphous (C/A) models, whereas its effect on wear in amorphous/crystalline (A/C) models is minimal. Additionally, the formation of new grains and twins is observed in the [001]-oriented C/A model during scratching. And the orientations of the new grain and the matrix are [111] new grain ||[100] matrix , new grain ||[010] matrix and new grain ||[001] matrix . The friction coefficients and wear rates observed in A/C models closely align with those of their monocrystalline counterparts , attributing to the fact that the upper amorphous layer can also be regarded as a protective layer of the crystalline when suffering a larger penetration depth. Consequently, A/C models demonstrate lower friction coefficients and wear rates compared to C/A models, suggesting that the A/C models offers a more effective approach for enhancing the wear resistance of dual-phase nano-laminates. The work can provide a theoretical basis and guidance for the design of high-performance HEAs.