First-principles study of helium behaviors in oxide dispersion strengthened nickel alloys

Y-Al-O oxides are characterized to be primary nanoprecipitates in oxide dispersion strengthened (ODS) Ni-based alloys for Very High Temperature Reactor (VHTR). We reported a first-principles study to assess the mechanical properties and helium behaviors in YAlO3(YAH) strengthened Ni-based ODS alloys from the nickel grain boundary and YAlO3 bulk to the Ni/ YAlO3 interface. The results suggest that YAH shows a elastic manner and well deformation compatibility with the matrix. The oxide strengthened system is expected to inhibit the formation of helium bubbles by capturing helium atoms dispersedly in YAlO3 bulk and Ni/ YAlO3 interface and thus hinder the He induced embrittlement.These findings provide basic understandings of the helium behaviors in a Al-cotnaining Ni-based ODS alloy.

Automated summary

In this study, the mechanical properties and helium behaviors in YAlO3 (YAH) strengthened Ni-based ODS alloys were assessed using first-principles calculations. The results indicate that YAH shows elastic deformation compatibility with the matrix and can capture dispersed helium atoms, inhibiting the formation of helium bubbles and preventing helium-induced embrittlement.