Effect of Energy Density on the Microstructure and Properties of the CrFeCoNiNb High Entropy Cladded Layer

A synergistic combination of mechanical properties and corrosion resistance property is desired for most ocean engineering structural applications. In this paper, we prepared high entropy alloy (HEA) cladded layer of composition CrFeCoNiNb (atomic%). We aim to attain a balance between the mechanical property and the corrosion resistance property through adjusting the energy density. The prepared CrFeCoNiNb cladded layer with the energy density of 116.7J/mm2 exhibited excellent mechanical properties and high corrosion resistance. The improved mechanical properties are attributed to the fine grain strengthening, solid solution strengthening and dispersion strengthening. Whereas the excellent corrosion resistance is due to the fine grained BCC single phase structure and the compact passivation film. The variation of the mechanical properties and corrosion resistance with different energy densities are attribute to the phase composition. The diffraction peak area of the main phase of BCC decreases first and then increases with the increase of energy density, which is the main reason that the hardness of the cladded layer follows the similar trend. The outcome of our research suggests that the prepared CrFeCoNiNb cladded layer could be explored to realise surface strengthening of load-bearing parts in marine engineering equipment.