Abstract
The emergence of compositionally complex alloys (CCAs) and phase-predictive software has enabled the microstructure-informed optimization of corrosion-resistant elements to promote stainless behavior. The relatively high solubility of lightweighting elements (LWEs) Al, Si, and Ti in face-centered cubic (FCC) CCA microstructures offers a promising path toward lower-density austenitic alloys. In this work, a set of single-phase FCC alloys based on Ni43Fe37Cr10-(Al,Si,Ti)10—excluding Mn and Co—was designed using high-throughput CALPHAD modeling and fabricated via arc melting. This composition space enabled a controlled study of LWE influence on relevant properties while maintaining chemical homogeneity. LWE additions reduced density and increased hardness relative to a control alloy without LWEs, with Al and Ti producing the most pronounced effects on each property, respectively. Two key electrochemical parameters—passive film growth rate and resistance—were quantified, with Ti showing the strongest per-atom effect: a greater than 10-fold increase in film resistance and 4-fold increase in growth rate relative to the control alloy. Post-hoc XPS results and in operando tracking of elemental dissolution rates measured via AESEC suggest rapid surface enrichment by LWE, providing an explanation for the observed electrochemical benefits of LWE inclusion. Finally, unsupervised clustering analysis identified simple quantitative design rules for corrosion: Ti greater than 3 at.% promotes both fast film growth and higher passive film resistance, while Si greater than 5 at.% or Ti at 3 at.% yields rapid growth but lower resistance.
| Original language | English |
|---|---|
| Article number | 102495 |
| Journal | Materialia |
| Volume | 43 |
| DOIs | |
| State | Published - Sep 2025 |
Funding
The authorship team acknowledges and appreciates the funding provided by the Office of Naval Research (ONR), USA through the grant N00014-23-1-2441, managed by program manager Dr. David Shifler. Junsoo Han and AESEC experiments performed by Debashish Sur were partially supported by the French government's “France 2030” initiative through the PEPR-DIADEM (Priority Research Programs and Equipment - Integrated Devices for Accelerating the Deployment of Emerging Materials) program, managed by the French National Research Agency (Agence Nationale de la Recherche, ANR), France, n°ANR-23-PEXD-0006. Debashish Sur is grateful for the financial support from the UVA SEAS Olsen Graduate Fellowship, USA for the duration of this study. Instruments PHI VersaProbe III, Quanta 650 and Thermo Scientific Phenom XLG2 SEMs, Phenom XLG2 XRD, Themis 60–300 kV Transmission Electron Microscope, and Tinius Olsen hardness tester, supported by UVA's Nanoscale Materials Characterization Facility (NMCF), were critical to the completion of this work. The authorship team thanks Helge Heinrich in particular for his help in performing TEM analysis. The PHI VersaProbe III system was supported by National Science Foundation, USA Award no. 162601. Thanks to Diego Ibarra Hoyos for fabricating an additional set of Si5Ti5 and Si7Ti3, and colleagues, Samuel B. Inman and Timothy Montoya, for their invaluable input during testing and writing this article. The authorship team acknowledges and appreciates the funding provided by the Office of Naval Research (ONR), USA through the grant N00014-23-1-2441 , managed by program manager Dr. David Shifler. Junsoo Han and AESEC experiments performed by Debashish Sur were partially supported by the French government’s “France 2030” initiative through the PEPR-DIADEM (Priority Research Programs and Equipment - Integrated Devices for Accelerating the Deployment of Emerging Materials) program, managed by the French National Research Agency (Agence Nationale de la Recherche, ANR), France , n° ANR-23-PEXD-0006 . Debashish Sur is grateful for the financial support from the UVA SEAS Olsen Graduate Fellowship, USA for the duration of this study. Instruments PHI VersaProbe III, Quanta 650 and Thermo Scientific Phenom XLG2 SEMs, Phenom XLG2 XRD, Themis 60–300 kV Transmission Electron Microscope, and Tinius Olsen hardness tester, supported by UVA’s Nanoscale Materials Characterization Facility (NMCF), were critical to the completion of this work. The authorship team thanks Helge Heinrich in particular for his help in performing TEM analysis. The PHI VersaProbe III system was supported by National Science Foundation, USA Award no. 162601 . Thanks to Diego Ibarra Hoyos for fabricating an additional set of Si5Ti5 and Si7Ti3, and colleagues, Samuel B. Inman and Timothy Montoya, for their invaluable input during testing and writing this article.
Keywords
- AESEC
- Aqueous corrosion
- Compositionally complex alloys
- Density
- EIS
- Hardness
- Lightweighting
- Passivity
- XPS