Y添加对CoCrFeMnNi高熵合金组织及力学性能的影响

The effects of Y addition on the microstructure and mechanical properties of (CoCrFeMnNi) _100-xY_x(x=0, 1, 2, 3, 4) high entropy alloys were investigated. The results indicate that the second phase of HCP structure rich in Y and Ni is formed with the increase of x to 2, presenting a long strip shape. When x=4, the HCP phase is distributed in a rectangular network shape, with the black Y-rich intermetallic compounds distributed. With the increase of Y content, the volume fraction of the second phase is increased gradually. The addition of Y promotes the atomic size difference and enthalpy-entropy ratio of the alloy, contributing to the formation of the second phase. The mechanical properties reveal that the compressive strength and microhardness are gradually increased with the increase of Y content. The yield strength and microhardness of (CoCrFeMnNi)₉₆Y₄ alloy are 521 MPa and 321.6 HV, which are increased by 178.6% and 100.6%, respectively, compared with those of the matrix CoCrFeMnNi alloy(187 MPa, 160.3 HV). The enhancement of the strength and hardness of the alloys is mainly attributed to the increase of the volume fraction of the second phase in the entropy alloys.