M. Siadat-Cheraghi, S. R. Allahkaram, Z. Shahri,
Volume 12, Issue 1 (3-2015)
Abstract
Pure cobalt coatings were electrodeposited on copper substrate by means of direct electric current in a
chloride solution at different current densities in the range of 10-70 mA cm
-2
. The surface morphology and
microstructure were investigated via X-ray diffraction analysis and scanning electron microscopy. Corrosion behavior
of cobalt coatings was also studied in a 3.5 wt% NaCl solution using potentiodynamic polarization and impedance
spectroscopy techniques. The results showed that corrosion resistance of deposits was strongly influenced by the
coating’s morphology. Co deposit obtained in lower current densities exhibited the highest corrosion resistance, due
to their lower grain boundaries and so the least density of active sites for preferential corrosion attacks