Abstract
The present work investigates the influence of Al-content and potential-scan-rate on stable/metastable pitting of Al xCoCrFeNi high-entropy alloys in a 3.5 wt.% NaCl solution. The increased Al content causes the volume fraction of the Cr-depleted phase to increase, resulting in thicker/dispersive passive films that degrade the localized corrosion resistance. The varied stable/metastable pitting behavior under different potential scan rates indicates that pit generation is influenced by the properties of passive films and the interactions between chloride ions and the active sites. Furthermore, a mean-field theory is employed to predict the scan-rate dependent, power-law distribution of current fluctuations.
Original language | English |
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Pages (from-to) | 33-45 |
Number of pages | 13 |
Journal | Corrosion Science |
Volume | 119 |
DOIs | |
State | Published - May 1 2017 |
Externally published | Yes |
Funding
Y.S., X.X, and P.K.L. would like to acknowledge the financial support from the U.S. Department of Energy (DE-FE-0024054 and DE-FE-0011194). Y.S. is grateful to the China Scholarship Council for financial support during her visit to The University of Tennessee. Y.S. is grateful to Z.T., who has provided the Al xCoCrFeNi alloys. P.K.L. very much appreciates the support of the U.S. Army Research Office project (W911NF-13-1-0438), and the support from the U.S. National Science Foundation (DMR-1611180), respectively. B.Y. is very grateful for the support from the “863” Program of China under Nos. 2008AA031702 and 2012AA03A507.
Keywords
- A. Alloy
- B. Polarization
- C. Passive films
- C. Pitting corrosion