Abstract Effects of annealing temperature and cooling medium on the hexagonal close-packed (HCP) phase fraction and mechanical properties of a novel Co35Cr25Fe37.5Ni2.5 alloy are investigated. The uniformly initial grain size and different HCP phase fractions are obtained via the same annealing temperature and different cooling mediums. The HCP phase area fraction is doubled as the cooling medium of water is replaced by liquid nitrogen, and the main reason is the rapid increase of nucleation sites of liquid nitrogen cooling. HCP laminates with different orientations intersect within grains. The yield strength and ultimate tensile strength of Co35Cr25Fe37.5Ni2.5 alloys annealing at 900 °C with liquid nitrogen quenching are ~482 MPa and ~1079 MPa, respectively. Contributions of the FCC phase and HCP phase to yield strength are discussed. The results indicate the combination of annealing temperature and cooling medium is an efficient manipulation method to adjust the HCP phase fraction and mechanical properties of dual phase high entropy alloy.

中文翻译：

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退火温度和冷却介质对新型双相高熵合金组织和力学性能的影响

摘要 研究了退火温度和冷却介质对新型Co35Cr25Fe37.5Ni2.5合金六方密堆积(HCP)相分数和力学性能的影响。通过相同的退火温度和不同的冷却介质获得均匀的初始晶粒尺寸和不同的 HCP 相分数。随着水的冷却介质被液氮取代，HCP相面积分数增加了一倍，主要原因是液氮冷却的成核点迅速增加。具有不同取向的 HCP 层压板在晶粒内相交。Co35Cr25Fe37.5Ni2.5 合金在 900 °C 退火液氮淬火的屈服强度和极限抗拉强度分别为~482 MPa 和~1079 MPa。讨论了 FCC 相和 HCP 相对屈服强度的贡献。