High hardness dual-phase high entropy alloy thin films produced by interface alloying

In this work, we present a tunable alloying strategy to prepare high entropy alloy (HEA) thin films with FCC/BCC dual-phase structure. The dual-phase HEA films consist of uniformly equiaxed grains with average size about 40 nm. Comparing with single-phase FCC HEA, the dual-phase HEA has higher hardness up to 10.4 GPa. The relative large atomic radius of Al leads to severe lattice distortion, resulting in a stronger solid solution strengthening behavior in the dual-phase HEA. Moreover, high dense heterogeneous phase interfaces effectively blocking dislocation motion enhance the strain hardening ability further. (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.