Effect of Fe content upon the microstructures and mechanical properties of FeₓCoNiCu high entropy alloys

Abstract

Four FexCoNiCu (x = 1.5, 2, 2.5 and, 3) high entropy alloys were fabricated by vacuum inductive melting method. The impact of the percentage of Fe on crystal structure transition, microstructure evolution and mechanical properties were studied. The results show that with the increase Fe content the crystal structure of the alloys gradually transformed from FCC to a mix of FCC and BCC phases. Cu segregation and precipitates containing high Fe content were also observed. The hardness was found to increase steadily from 304 HV to 672 HV due to the increase of fraction of BCC phase. In contrast, the tensile strength firstly increased from 392 MPa to 639 MPa, and then decreased to 576 MPa.