First-principles investigation of hydrogen trapping and diffusion at grain boundaries in nickel

摘要: Abstract In this work, the interaction of hydrogen with high-angle GBs in nickel has been investigated by means density functional theory simulations. Two distinct types have considered: Σ 3 ( 1 ) [ ¯ 0 ] a close-packed interface structure and 5 2 less dense consisting open structural units. Our calculations reveal that these two markedly different behavior atomic hydrogen. The GB neither traps H nor enhances its diffusion, but instead acts as two-dimensional diffusion barrier. contrast, provides numerous trapping sites for within units well easy migration pathways along plane can enhance diffusivity about orders magnitude compared to bulk Ni. obtained results are analysed detail available experimental other theoretical data.