10.1016/j.actamat.2025.121556">
 

Atomistic mechanisms of oxidation and chlorine corrosion in Ni-based superalloys: The role of boron and light interstitial segregation

Document Type

Article

Publication Date

9-24-2025

Abstract

Hybrid Monte Carlo and molecular dynamics simulations were used to investigate the interaction of light interstitials in multi-element Ni-based alloys. We show that light interstitials such as boron and oxygen fundamentally alter interfacial chemistry by reshaping alloy-element distribution and segregation. Oxygen adsorption drove boron migration from the grain boundary to the free surface, where it co-enriched with Cr, Fe, and Mo and formed BO3 trigonal motifs embedded within mixed-metal oxide networks. Oxygen also promoted M-O-M chain formation, including Nb2O5 clusters at the free surface. In the absence of oxygen, boron segregated to the grain boundary, altering local metal chemistry and underscoring a dynamic, environment-sensitive behavior. Following chlorine exposure, the oxidized surfaces retained strong O-mediated connectivity while forming new Cl-M associations, particularly with Nb and Cr, and exhibited further surface enrichment in Cr, Fe, and Mo. High-temperature MD simulations revealed a dynamic tug-of-war: chlorine exerted upward pull and disrupted weakly anchored sites, while Nb- and BO3-rich oxide motifs resisted deformation. A new stabilization mechanism was identified in which subsurface boron atoms anchored overlying Cr centers, suppressing their mobility and mitigating chlorine-driven displacement. These results demonstrate boron's dual role as a modifier of alloy-element segregation and a stabilizer of oxide networks, and identify Nb as a key element in reinforcing cohesion under halogen attack. More broadly, this study highlights the need to track light interstitial cross-talk and solute migration under reactive conditions, offering atomistic criteria for designing corrosion-resistant surface chemistries in Ni-based superalloys exposed to halogenated or oxidative environments.

Comments

This subscription-article is published by Elsevier and appears in Acta Materialia as cited. The published version is located at the Version of Record DOI link below.

The "Link to Full Text"on this page opens or saves the PDF of the preprint, as found at the arxiv.org repository. The preprint version is cited as:

arXiv:2509.19232 [cond-mat.mtrl-sci], Preprint record: https://doi.org/10.48550/arXiv.2509.19232

The linked version at arXiv is an Open Access preprint distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives License, which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited, and is not altered, transformed, or built upon in any way. CC BY-NC-ND 4.0

Author note: Co-author T. Doležal was co-affiliated with AFIT and MIT at the time of this publication.

DOI

Version of Record: 10.1016/j.actamat.2025.121556

Source Publication

Acta Materialia (ISSN 1359-6454 | eISSN 1873-2453)

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