Abstract

L12 precipitates are usually induced into face-centered cubic (FCC) multiple-principal element alloys (MPEAs) to improve their moderate yield strength; however, the precipitation also influences the corrosion resistance. This study investigated the corrosion behavior and passive film performance of a series of L12-strengthened Ni28Cr15Cu8Ti8Fe26-xCo15+x (x = 0, 3, 6, and 9 at.%) MPEAs in 3.5 wt.% NaCl solution. The size and density of the L12 nanoprecipitates were regulated via tuning Fe and Co content. With decreasing Fe/Co ratio, the radii of these nanoprecipitates gradually increased within the range of 2–4 nm, while their volume fraction exhibited a trend of first increasing and then decreasing. Accordingly, the corrosion current density (Icorr) of the alloys first decreased and then increased. In detail, the Ni28Fe23Co18Cr15Cu8Ti8 MPEA exhibited the optimal corrosion resistance to 3.5 wt.% NaCl solution, showing a minimum Icorr of 23 nA/cm2 and a highest pitting potential (Epit) of 301 mVSCE. This tendency suggested that finer and denser L12 nanoprecipitates contribute to enhancing corrosion resistance. The remarkable corrosion resistance originated from the uniform and dense passive film with a high content of Cr oxides, O2−/OH− ratio and bound water content. Additionally, the significantly higher antibacterial rate of the Cu-containing Ni28Fe23Co18Cr15Cu8Ti8 alloy compared to its Cu-free counterpart demonstrated that Cu addition could improve the resistance to microbial adhesion.

Department(s)

Materials Science and Engineering

Publication Status

Full Text Access

Keywords and Phrases

Corrosion resistance; L12 nanoprecipitates; Multi-principal element alloys; Passive film

International Standard Serial Number (ISSN)

1044-5803

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2026 Elsevier, All rights reserved.

Publication Date

01 Jul 2026

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