Corrosion tests of nickel coatings prepared from a Watts-type bath

摘要

This paper deals with the preparation and characterization of thin Ni layers. The electrodeposit-ion was carried out galvanostatically from a Watts bath at different current densities in the range from 1 to 10 A dm~(-2) and for deposition times between 900 and 7200 s. The structure and the morphology of the nickel coatings were investigated by SEM and XRD techniques. The microhardness of deposited layers, the electrochemical behavior and the corrosion properties of the deposits were investigated by means of Vickers microhardness, polarization measurements, and electrochemical impedance spectroscopy (EIS). The uniform deposits showed fine grains and good protection against corrosion.