Abstract
Single-phase multi-principal element alloys hold promise for improved mechanical properties as a result of multiple operative deformation modes. However, the use of many of these alloys in structural applications is limited as a consequence of their poor aqueous corrosion resistance. Here we introduce a new approach for significantly improving the passivation behavior of alloys by tuning the chemical short-range order parameter. We show that the addition of only 0.03 to 0.06 mole fraction of Al to a (FeCoNi)0.9Cr0.1 alloy changed both the magnitude and sign of the Cr-Cr order parameter resulting in passivation behavior similar to 304L stainless steel containing twice the amount of Cr. Our analysis is based on comparing electrochemical measures of the kinetics of passive film formation with chemical short-range order characterizations using time-of-flight neutron scattering, cluster expansion methods, density functional theory and Monte Carlo techniques. Our findings are interpreted within the framework of a recently proposed percolation theory of passivation that examines how selective dissolution of the non-passivating alloy components and short-range order results in excellent passive films at reduced levels of the passivating component.
Original language | English (US) |
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Article number | 120209 |
Journal | Acta Materialia |
Volume | 277 |
DOIs | |
State | Published - Sep 15 2024 |
Funding
MT, JRS, CW, TMM and KS acknowledge support of this research by the Office of Naval Research, Multidisciplinary University Research Initiative program, \u201CFrom Percolation to Passivation (P2P): Multiscale Prediction and Interrogation of Surface and Oxidation Phenomena in Multi-Principal Element Alloys\u201D under Grant Number N00014-20-1-2368. The neutron scattering portion of this research conducted at Oak Ridge National Laboratory's Spallation Neutron Source was sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy. The neutron analysis was performed using the Advanced Research Computing at Hopkins (ARCH) core facility (rockfish.jhu.edu), which is supported by the National Science Foundation under grant number OAC 1920103. Materials processing was performed at the Platform for the Accelerated Realization, Analysis, and Discovery of Interface Materials (PARADIM at JHU), a National Science Foundation Materials Innovation Platform under grant number NSF DMR-2039380. The PHI Versa-Probe III XPS, Empyrean X-ray diffractometer and Quanta 650 SEM work was performed at the University of Virginia Nanoscale Materials Characterization Facility. The PHI Versa-Probe III system was supported by NSF grant number 162601 - \"MRI Acquisition of an X-Ray Photoelectron Spectrometer for Chemical Mapping of Evolving Surfaces: A Regional Instrument for Research and Teaching.\u201D
Keywords
- Chemical short-range order
- Corrosion passivation
- Density functional theory
- Multi-principle element alloys
- Neutron scattering
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Polymers and Plastics
- Metals and Alloys