Evolution of the included hydrogen, internal stress, microhardness and microstructure of electrodeposited cobalt

Article abstract of DOI:10.1016/0013-4686(89)87164-6

An interrupted electrolysis with different duration of the pause (zero current)-τ_off for the plating of cobalt layers is applied. The alteration of their internal stress (IS), microhardness and microstructure with variable τ_off within the range 0-900 s and constant plating period τ_on = 120 s is investigated. The amounts of hydrogen leaving the coating both after the deposition is over, ν_H and during the pauses, ν_H^off, are determined. A permanence of the structure (phase composition, crystalline orientation and coherent scattering domain size) of cobalt coatings, deposited both by conventional and interrupted electrolysis regardless of the pause duration is established. The increasing total amount of desorbed hydrogen, ν_H^* = (ν_H^off + v_H), as τ_off becomes longer is the cause of the observed augmentation of the IS, microdeformation and decrease of microhardness.