Diffusion controlled helium bubble formation resistance of FeCoNiCr high-entropy alloy in the half-melting temperature regime

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalNot applicablepeer-review

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Author(s)

  • Jianrong Sun
  • Pengfei Tai
  • Yanbin Sheng
  • Yilu Zhao
  • Guma Yeli
  • Wu Kai

Detail(s)

Original languageEnglish
Article number151747
Journal / PublicationJournal of Nuclear Materials
Volume526
Online published8 Aug 2019
Publication statusPublished - 1 Dec 2019

Abstract

For the structure materials applied in advanced nuclear energy system, helium bubble formation is always a big concern which will severely degrade the performance of materials around or above the half-melting temperature regime (∼0.5 T). To explore the He bubble formation resistance in the FeCoNiCr alloy, that is a novel face-centered cubic (fcc) high-entropy alloy (HEA) showing excellent radiation damage tolerance, we conducted a series of 2 MeV He ions irradiation experiments on them at three different temperatures (0.46, 0.51 and 0.57 T). For reference purpose, a model fcc metallic system of pure Ni was irradiated simultaneously. Through transmission electron microscopy (TEM), He bubble formation in the irradiated samples was systematically investigated. The results show that in any designated temperature, He bubbles have a smaller size, higher number density, and denser distribution in the HEA when comparing to that of pure Ni. The volume fraction of He bubbles is also less in the HEA, suggesting a suppressed bubble evolution. For the underlying mechanism of the He bubble formation resistance of HEA, we suggest that the featured energy barriers for point defects migration in the HEA will promote the recombination of defects and somewhat reduce the vacancy concentration during irradiation. Such unique effect could suppress the He diffusion through vacancy mechanism, it will finally influence the evolution of He bubbles in the HEA.

Research Area(s)

  • Helium bubbles, Helium diffusion, High-entropy alloy, Point defects behavior, Vacancy concentration

Citation Format(s)

Diffusion controlled helium bubble formation resistance of FeCoNiCr high-entropy alloy in the half-melting temperature regime. / Chen, Da; Zhao, Shijun; Sun, Jianrong; Tai, Pengfei; Sheng, Yanbin; Zhao, Yilu; Yeli, Guma; Lin, Weitong; Liu, Shaofei; Kai, Wu; Kai, Ji-Jung.

In: Journal of Nuclear Materials, Vol. 526, 151747, 01.12.2019.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalNot applicablepeer-review