Publication Date

2021

Journal or Book Title

NPJ Materials Degradation

Abstract

High-entropy alloys (HEAs) with multiple principal elements represent a paradigm shift in structural alloy design and show excellent surface degradation resistance in corrosive environment. Here, the tribo-corrosion response of laser-engineered net-shaped CoCrFeMnNi HEA was evaluated in 3.5 wt% NaCl solution at room temperature. The additively manufactured (AM-ed) CoCrFeMnNi showed five times lower wear rate, regenerative passivation, and nobler corrosion potential during tribo-corrosion test compared to its arc-melted counterpart. A significant anisotropy was seen in the tribo-corrosion response with 45 degrees to the build direction showing better performance compared to tests along the build direction and perpendicular to it. The open circuit potential curves were characterized by a sharp drop to more negative values as wear began, followed by continuous change for the active tribo-corrosion duration and finally a jump to nobler value at the end of the test indicating excellent surface re-passivation for the AM-ed alloy. The superior tribo-corrosion resistance of AM-ed CoCrFeMnNi was attributed to the refined microstructure and highly protective surface passivation layer promoted by the sub-grain cellular structure formed during additive manufacturing. These results highlight the potential of utilizing additive manufacturing of HEAs for use in extreme environments that require a combination of tribo-corrosion resistance, mechanical durability, extended service life, and net shaping with low dimensional tolerance.

ORCID

Shittu, Jibril/0000-0002-6345-6123

DOI

https://doi.org/10.1038/s41529-021-00177-2

Volume

5

Issue

1

License

UMass Amherst Open Access Policy

Creative Commons License

Creative Commons Attribution 4.0 License
This work is licensed under a Creative Commons Attribution 4.0 License.

Funder

U.S. Department of State; Center for Agile & Adaptive and Additive Manufacturing (CAAAM) through State of Texas Appropriation [190405-105-805008-220]; National Science FoundationNational Science Foundation (NSF) [CMMI-1927621, DMR-2004429]; UMass Faculty Startup; Materials Research Facility (MRF) at the University of North Texas; University of Nebraska at Omaha

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