Abstract: A CrCoNi medium-entropy alloy was prepared by using vacuum suspension melting furnace, then hot rolled at 900 ℃ for 50% deformation and further warm rolled at 500 ℃ for 50% deformation. The effect of rolling deformation on microstructure and mechanical properties of the CrCoNi alloy was studied by means of OM, XRD, SEM, hardness tester and universal test machine. The results show that the CrCoNi medium-entropy alloy has a simple single-phase FCC solid solution structure in as-cast state, and no new phase is generated during rolling deformation. The CrCoNi alloy has good plastic deformation ability, and its performance is greatly improved after plastic deformation. The tensile strength can reach 890 MPa and the elongation can reach 60% after hot rolling, and the strength can be further increased by increasing deformation and the combination of hot rolling+warm rolling. Severe lattice distortion, work hardening and fine-grain strengthening all promote the combination of high strength and good toughness.

Key words: CrCoNi medium-entropy alloy, rolling deformation, microstructure, mechanical properties