Hydrogen segregation at grain boundaries in nanocrystalline nickel

Chemomechanical effects on the separation of interfaces occurring during fracture with emphasis on the hydrogen-iron and hydrogen-nickel system

“…hydride NiH is formed in the bulk at 0.64 GPa and 295 K [17]. In the hydrostatically stressed region in front of a crack tip the hydride will even be formed at lower hydrogen pressures and this brittle hydride may enable crack extension [27].…”

“…Corresponding parameters for bulk hydrogen are from Ref. [17] and for Nisurface energies, c, from Ref. [18] and [19].…”

“…The results together with the interaction parameter W are compiled in Table 1, which also includes values for the bulk [17] and for grain boundaries. The latter were obtained from bulk values by assuming an average segregation energy of 20 kJ/mol-H or 40 kJ/mol-H 2 below the bulk value [17].…”

“…The latter were obtained from bulk values by assuming an average segregation energy of 20 kJ/mol-H or 40 kJ/mol-H 2 below the bulk value [17].…”

Solid Solutions of Hydrogen in Complex Materials

“…[14] and [81]. For H in nanocrystalline Ni experimental value are not available over the same large range of H-concentration but they can be described within the same framework of a distribution of segregation energies as well [83,84].…”