Hydrogen Desorption and Internal Stress in Nickel Coatings Obtained by Periodic Electrodeposition

Periodic electrodeposition is performed in order to determine to what extent a change in conditions for the desorption of hydrogen from nickel deposits, which is occluded during plating, can affect their internal stress. The duration of the pause (zero current), , is varied in the range 0–900 s and the plating period, , is kept constant, maintaining the structure unchanged. The variations of internal stress, microhardness, and coercivity of the electrodeposits obtained at different , are investigated. The amounts of hydrogen leaving the coating, both during the pauses and after the deposition is completed, are determined. A proof of the mechanical nature of intensive hydrogen codeposition at the beginning of nickel electroplating is obtained. It is shown that the desorption of hydrogen is responsible to a considerable extent for the high tensile internal stress observed in similar coatings.