Effects of co-alloying Al and Cu on the corrosion behavior and mechanical properties of nanocrystalline FeCrNiCo high entropy alloys

The complex element composition and enormous composition space of high entropy alloys (HEAs) adds more uncertainty to the material properties. Here, a series of nanocrystalline AlxCuy(FeCrNiCo)100−x-y (x = 6.44–50.51 at%, y = 8.49–40.31 at%) HEAs were high-throughput synthesized. Co-alloying Al and Cu effects on the corrosion resistance of FeCrNiCo HEAs were systematically investigated in a two-dimensional composition space, and the microstructure and mechanical properties of typical alloy compositions were examined. Experimental results show that nanocrystalline Al16.29Cu13.04(FeCrNiCo)70.67 and Al19.59Cu17.08(FeCrNiCo)63.33 alloys have balanced corrosion resistance, hardness and plasticity. The underlying mechanisms for co-alloying Al and Cu effects on the corrosion resistance and mechanical properties were analyzed.