Atomistic mechanism of nano-scale phase separation in fcc-based high entropy alloys

•Simplified atomic models are developed to investigate the nano-phase separation in FCC AlxCoCrCuFeNi HEAs.•The modeling results exhibit great consistency with the STEM observations.•The results provide physical insight into the atomic mechanism of nano-scale phase separation in HEAs.

Nano-scale phase separation and precipitation play a vitally important role in strengthening multi-component alloys, such as high entropy alloys (HEAs), which exhibit excellent physical and mechanical behaviors. Investigating their underlying atomistic mechanism is of great importance in understanding the strengthening mechanism of these complex alloy systems. In the present study, simplified atomic models have been developed to investigate the physical mechanism of the nano-phase separation in the fcc-based AlxCoCrCuFeNi HEAs at the atomic level. Furthermore, the modeling results agree well with the experimental observations from the state-of-the-art scanning transmission electron microscopy (STEM).