Understanding the hydrogen effect on pop-in behavior of an equiatomic high-entropy alloy during in-situ nanoindentation

Dong Wang, Xu Lu*, Meichao Lin, Di Wan, Zhiming Li, Jianying He, Roy Johnsen

*Corresponding author for this work

Research output: Contribution to journalLetterpeer-review

19 Citations (Scopus)

Abstract

The variations in the pop-in behavior of an equiatomic CoCrFeMnNi high-entropy alloy under different hydrogen charging/discharging conditions were characterized via in-situ electrochemical nanoindentation. Results show that hydrogen accumulatively reduces both pop-in load and width, among which the reduction of pop-in width is more noticeable than that of pop-in load. Moreover, the hydrogen reduction effect on both pop-in load and width is reversible when hydrogen is degassed during anodic discharging process. Particularly, the hydrogen-reduced pop-in width was studied in detail by a comprehensive energy balance model. It is quantitatively shown that the dissolved hydrogen enhances lattice friction, leading to an increased resistance to dislocation motion. As a result, fewer dislocations can be generated with a higher hydrogen concentration, causing a smaller pop-in width. This is the first time that the pop-in width indicated dislocation mobility under hydrogen impact is quantitively revealed.

Original languageEnglish
Pages (from-to)118-122
Number of pages5
JournalJournal of Materials Science and Technology
Volume98
DOIs
Publication statusPublished - 30 Jan 2022
Externally publishedYes

Keywords

  • Dislocation
  • High-entropy alloy
  • Hydrogen
  • Nanoindentation
  • Pop-in

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Wang, D., Lu, X., Lin, M., Wan, D., Li, Z., He, J., & Johnsen, R. (2022). Understanding the hydrogen effect on pop-in behavior of an equiatomic high-entropy alloy during in-situ nanoindentation. Journal of Materials Science and Technology, 98, 118-122. https://doi.org/10.1016/j.jmst.2021.04.060