hide
Free keywords:
Chromium alloys; Chromium metallography; Cobalt alloys; Cobalt metallography; Entropy; High-entropy alloys; Iron alloys; Iron metallography; Irradiation; Manganese alloys; Nickel metallography; Positron annihilation spectroscopy, Atomic diffusions; Mechanical behavior; Migration barriers; Particle irradiation; Preferential localization; Solute strengthening; Theoretical calculations; Vacancy diffusion, Manganese metallography
Abstract:
We present evidence of homogenization of atomic diffusion properties caused by C and N interstitials in an equiatomic single-phase high entropy alloy (FeMnNiCoCr). This phenomenon is manifested by an unexpected interstitial-induced reduction and narrowing of the directly experimentally determined migration barrier distribution of mono-vacancy defects introduced by particle irradiation. Our observation by positron annihilation spectroscopy is explained by state-of-the-art theoretical calculations that predict preferential localization of C/N interstitials in regions rich in Mn and Cr, leading to a narrowing and reduction of the mono-vacancy size distribution in the random alloy. This phenomenon is likely to have a significant impact on the mechanical behavior under irradiation, as the local variations in elemental motion have a profound effect on the solute strengthening in high entropy alloys. © 2021
