CURRENT EFFICIENCY AND CRYSTALLIZATION MECHANISM IN PULSE PLATING OF HARD CHROMIUM

The current efficiency of chromium deposition was investigated under c onditions of periodic current reversal. It has been demonstrated that the relationship between the anodic and the cathodic charges, Q(a)/Q(c ), has a strong influence on the current efficiency and the structure of the deposit. A plausible model for the crystallization mechanism du ring periodic current reversal has been suggested. According to the mo del, an advantageous chromium structure is maintained during the depos ition process because interstitial hydrogen in the chromium lattice is oxidized during the anodic period.