CoCrFeNi high-entropy alloy, a single-phase structure, has been extensively studied for its outstanding corrosion resistance and excellent low-temperature ductility. However, the low strength and wear properties restricts its application prospects. Many alloys, high-entropy alloys containing Laves phase have higher strength and hardness, provide a new research direction for obtaining alloys with high strength, wear resistance and corrosion resistance.

 In this work, the CoCrFeNiZrx high-entropy alloys were prepared by medium frequency electromagnetic induction melting. The effects of Zr contents on the microstructure, mechanical properties and corrosion resistance of CoCrFeNi-based high-entropy alloys were studied. With the increase of Zr content, the phase consititution of the of CoCrFeNiZrx alloys changed as follows: FCC  FCC + C15 Laves BCC + C15 Laves. Meanwhile, the Vickers hardness of the alloy increases with the increase of the volume fraction of C15 Laves phase, but the ductility decreases at room temperature. In addition, the corrosion resistance of the three alloys containing Zr is lower than that of the Zr-free alloy. Electrochemical impedance spectroscopy (EIS) and Motschottky (MS) results show that the addition of Zr reduces the stability and compactness of the passivation film on the surface of the alloy, and the selective corrosion occurs.