Hydrogen diffusion in ultrafine-grained palladium: Roles of dislocations and grain boundaries

Hideaki Iwaoka, Makoto Arita, Zenji Horita

Research output: Contribution to journalArticlepeer-review

37 Citations (Scopus)


Diffusion behavior of hydrogen in ultrafine-grained palladium (Pd) is investigated by electrochemical permeation tests. The ultrafine-grained structure is produced by severe plastic deformation through high-pressure torsion (HPT). The diffusion behavior is compared with an annealed state with a coarse-grained structure and a cold-rolled state with dislocations and subgrain structures. Hydrogen permeation is analyzed in absorption step and desorption step at five different temperatures in the range of 15-35°C. Hydrogen diffusion is retarded due to hydrogen trapping by dislocations. Grain boundaries act as rapid diffusion paths for hydrogen so that hydrogen diffusion is enhanced in the HPT-processed Pd samples with the ultrafine-grained structures.

Original languageEnglish
Pages (from-to)168-177
Number of pages10
JournalActa Materialia
Publication statusPublished - Apr 1 2016

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Ceramics and Composites
  • Polymers and Plastics
  • Metals and Alloys

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