Simulations of irradiation resistance and mechanical properties under irradiation of high-entropy alloy NiCoCrFe

Y Yu and Y Yu, MATERIALS TODAY COMMUNICATIONS, 33, 104308 (2022).

DOI: 10.1016/j.mtcomm.2022.104308

Investigating how High-entropy alloys (HEAs) perform after high energy irradiation is significant for its indus-trial application. In this work, molecular dynamics simulations have been conducted to clarify the irradiation damage process of NiCoCrFe high-entropy alloy (HEA) after low energy (5 KeV), medium energy (30 KeV), and high energy (70 KeV) irradiation. Irradiation energy up to 70 KeV is used to reflect the high-energy irradiation response of HEAs. The intrinsic evolution after applying tensile stress to the irradiated system is revealed. We find that the distribution of irradiation defects in NiCoCrFe is relatively scattered. And because of atomic dis-ordering, the lower thermal conductivity and the retarded motion of interstitial defects enable Frenkel pairs in NiCoCrFe to recombine. Thus smaller clusters and fewer dislocations are found, especially when exposed to high-energy radiation. As a result, the decline of the mechanical properties such as ultimate strength and ductility is less in NiCoCrFe than Ni when applying tensile stress to the irradiated systems. Remarkably, In NiCoCrFe, the declining rate of ultimate strength and yield strain after high energy irradiation has only a 1 % increase compared with medium energy irradiation. These results demonstrated the radiation resistance of high-entropy alloys, and reflect the stability of the mechanical properties of NiCoCrFe withstanding high-energy radiation.

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