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Title: Hydrogenated vacancies lock dislocations in aluminium

Due to its high diffusivity, hydrogen is often considered a weak inhibitor or even a promoter of dislocation movements in metals and alloys. By quantitative mechanical tests in an environmental transmission electron microscope, here we demonstrate that after exposing aluminium to hydrogen, mobile dislocations can lose mobility, with activating stress more than doubled. On degassing, the locked dislocations can be reactivated under cyclic loading to move in a stick-slip manner. However, relocking the dislocations thereafter requires a surprisingly long waiting time of ~10 3 s, much longer than that expected from hydrogen interstitial diffusion. Both the observed slow relocking and strong locking strength can be attributed to superabundant hydrogenated vacancies, verified by our atomistic calculations. In conclusion, vacancies therefore could be a key plastic flow localization agent as well as damage agent in hydrogen environment.
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  1. Xi'an Jiaotong Univ., Xi'an (China)
  2. Karlsruhe Inst. of Technology (KIT), Karlsruhe (Germany)
  3. Karlsruhe Inst. of Technology (KIT), Karlsruhe (Germany); Fraunhofer-Institut fur Werkstoffmechanik IWM, Freiburg (Germany)
  4. Xi'an Jiaotong Univ., Xi'an (China); Johns Hopkins Univ., Baltimore, MD (United States)
  5. Xi'an Jiaotong Univ., Xi'an (China); Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
Publication Date:
Grant/Contract Number:
FG02-03ER46056; FG02-09ER46056
Accepted Manuscript
Journal Name:
Nature Communications
Additional Journal Information:
Journal Volume: 7; Journal ID: ISSN 2041-1723
Nature Publishing Group
Research Org:
Johns Hopkins Univ., Baltimore, MD (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
36 MATERIALS SCIENCE; mechanical properties; metals and alloys; Metals; Alloys
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1393400