A scale-up investigation for the electrodeposition of highly active Ni-Zn and Ni-Co-Zn cathode coatings

New methodologies were used to characterize Ni-Zn and Ni-Co-Zn electrodeposits on 200 cm(2) mild steel plates in a non-destructive way. A correlation between deposition potential and Zn content in the alloy was obtained using a rotating multielectrodic Hull cell. The resulting linear relationship allows to evaluate ''a priori'' the amount of Zn in the deposits. A small electrochemical cell ended in an O-ring was used to measure local roughness factors, composition and activity towards the hydrogen evolution reaction. The observed variations in local activity were attributed to differences in the surface morphology of the coatings.