Origin of micrometer-scale dislocation motion during hydrogen desorption
Author(s)Koyama, Motomichi; Taheri Mousavi, Seyedeh Mohadeseh; Yan, Haoxue; Kim, Jinwoo; Cameron, Benjamin Clive; Moeini Ardakani, Sina(Seyed Sina); Li, Ju; Tasan, Cemal; ... Show more Show less
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Hydrogen, while being a potential energy solution, creates arguably the most important embrittlement problem in high-strength metals. However, the underlying hydrogen-defect interactions leading to embrittlement are challenging to unravel. Here, we investigate an intriguing hydrogen effect to shed more light on these interactions. By designing an in situ electron channeling contrast imaging experiment of samples under no external stresses, we show that dislocations (atomic-scale line defects) can move distances reaching 1.5 μm during hydrogen desorption. Combining molecular dynamics and grand canonical Monte Carlo simulations, we reveal that grain boundary hydrogen segregation can cause the required long-range resolved shear stresses, as well as short-range atomic stress fluctuations. Thus, such segregation effects should be considered widely in hydrogen research. ©2020 The Authors.
DepartmentMassachusetts Institute of Technology. Department of Materials Science and Engineering; Massachusetts Institute of Technology. Department of Mechanical Engineering; Massachusetts Institute of Technology. Department of Civil and Environmental Engineering; Massachusetts Institute of Technology. Department of Nuclear Science and Engineering
American Association for the Advancement of Science (AAAS)
Koyama, Motomichi et al., "Origin of micrometer-scale dislocation motion during hydrogen desorption." Science Advances 6, 23 (June 2020): eaaz1187 doi. 10.1126/sciadv.aaz1187 ©2020 Authors
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