Electrochemical processes during plating Fe powder particles by Ni and Ni/Cu coating in the fluidized bed

Ni electrodeposition on Fe powder was studied with respect to an inhibiting adsorbed hydroxycomplex layer. Its elimination was done in three possible ways: by increasing the rotation speed of the circular stirring of the suspension, by chemical dissolution of the adsorbed layer during interrupted electrolysis, and by addition of a complexing agent – sodium citrate into the electrolyte. The simultaneous deposition of a Cu/Ni coating was enabled by proper electrolyte composition as to the ratio of both metallic compounds and by the addition of a suitable complexing agent. The Cu/Ni ratio was influenced, beside electrochemical parameters, also by the particle size of the Fe powder and by the suspension density. Increasing the suspension density supports the deposition of Ni, and increasing the particle size supportsthe deposition of Cu. Electronic Publication