Electrochemical behaviour of amorphous electrodeposited chromium coatings

Results obtained by studying the electrochemical characterisation of the passive dissolution and corrosion behaviour of amorphous chromium coatings are reported and discussed. An electrolyte based on trivalent chromium, complexed with glycine, was used in conjunction with a high speed flow electrodeposition cell. The structure, morphology and elemental analysis of chromium coatings deposited on copper substrates using various bath variables (bath temperatures of 30 and 60 °C; current densities of 0.3–1.8 A cm−2; and flow rates of 0.2, 0.3 and 1.4 m s−1) were investigated by XRD and SEM/EDS. As a network of micro-cracks was found on all the amorphous chromium deposits running from the deposit surface to the copper substrate, mild electrochemical passivation conditions were applied to avoid the copper substrate being subjected to corrosive attack.