Work

Chemical short-range order regulates hydrogen energetics and hydrogen-dislocation interactions in CoNiV

Year: 2026

Type: article

Abstract: Chemical short-range order (CSRO) has emerged as a critical structural feature in concentrated alloys, yet its coupling with hydrogen remains an active discussion. Here, we develop a machine-learning interatomic potential for the Co-Ni-V-H system and investigate how CSRO regulates hydrogen energetics and dislocation behavior in CoNiV, an alloy with reported strong resistance to hydrogen embrittlement. We identify strong V-centered ordering that suppresses V–V clustering and remains robust up to 1000 K, with negligible changes upon the addition of 1.0 at.% hydrogen. Compared to a chemically random alloy, the ordered state exhibits higher average hydrogen solution energies and a reduced population of strongly binding sites, suggesting lower bulk hydrogen uptake. At partial dislocations, hydrogen preferentially segregates to tensile core regions, where the dislocation core acts as a shallow, reversible trap, with a much weaker effect compared to chemical trapping states. These results show that robust local chemical order plays a critical role in affecting H uptake, partitioning, and dislocation trapping in concentrated CoNiV alloys.

Source: npj Computational Materials

DOI: 10.1038/s41524-026-02274-9

Authors: Beihan Chen, Dalia M. Sayed Ahmed, Yang Yang, Miaomiao Jin

Institution: Pennsylvania State University

Language: English

Topic: Hydrogen embrittlement and corrosion behaviors in metals

Subfield: Metals and Alloys

Field: Materials Science

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $3,490

Funders: U.S. Department of Energy, National Energy Research Scientific Computing Center, Office of Science, Basic Energy Sciences