First-principles study of He behavior in a NiCoFeCr concentrated solid–solution alloy

Abstract

The unusual mechanical and radiation properties found in concentrated solid–solution alloys (CSAs) make them promising candidate materials in nuclear applications. In this work, He behavior in a typical CSA, NiCFeCr, is assessed by first-principles calculations. Our results suggest that the energy difference of He in substitutional and interstitial sites is greatly reduced. The energy barriers of He through both interstitial and substitutional diffusion are much higher than those in pure Ni, indicating slower He dynamics in CSAs. The calculated activation energies show that the dissociation mechanism is more favorable in NiCoFeCr, which helps to suppress He growth as observed experimentally.

Keywords

• Helium bubble
• defect properties
• concentrated solid–solution alloys
• ab initio calculations
• radiation damage