A c c e p t e d M a n u s c r i p t • Bulk distributed hydrogen facilitates brittle intergranular fracture.• Vacancy distributed hydrogen facilitates void assisted locally plastic fracture.• Hydrogen containing systems yield reduced failure strains and tensile toughness.• Finite temperature and strain rate effects attributed to structural relaxation.• Hydrogen diffusivity depends on microstructure change during plastic deformation.
AbstractHydrogen embrittlement studies using reactive molecular dynamics have been conducted for Al metal nanoslabs with oxidized surfaces. These have provided evidence for possible grain boundary decohesion and void formation related range of hydrogen embrittlement mechanisms at different loading conditions with different initial defect configurations. Particularly, the effect of initial vacancy concentration on hydrogen diffusivity and localization, as well as on the amount of plasticity and grain formation is estimated. The results indicate significant reduction in diffusivity due to vacancy concentration, as well as hydrogen embrittlement effect through increase in dislocation emission and increase in dislocation slip propagation rate.