Ultra-high strength and ductility of eutectic high-entropy alloy with duplex heterostructure at room and cryogenic temperatures
Xiangkui Liu, Jingying Liu, Chenglong Zhou, Weixia Dong, Xuecong Zhang, Q. Wang, Huiqing Xu, Xulong An, Dandan Wang, Wei Wei, Zhenfei Jiang
Abstract
Here, we architected a duplex heterostructure with FCC/L1 2 and B2 phases in Ni 49 Fe 28 Al 17 V 6 eutectic high-entropy alloy (EHEA) by thermal-mechanical process. Ultra-high yield strength of ∼1550 MPa, high tensile strength of ∼1772 MPa and good ductility of ∼16.5 % at room temperature (298 K) were exhibited. Particularly, ultra-high yield strength of ∼1877 MPa, ultra-high tensile strength of ∼2157 MPa and uniform elongation of ∼10 % were achieved at cryogenic temperature (77 K). Such excellent room-temperature mechanical properties are attributed to the hetero-deformation induced (HDI) hardening. Ultrahigh cryogenic-temperature strength originates from not only HDI hardening, but also the strong interaction of deformation twins and high-density dislocations.