Charge-Modulated Chromium III Plating to Dispel Hydrogen Effects

摘要

Conventional electroplating processes utilize complicated bath chemistries to achieve performance requirements. Consequently, new processes for replacement coatings for hexavalent chromium have proved difficult to develop. For example, thick deposits with appropriate properties from tri-chromium plating are unobtainable due to hydrogen effects. Charge modulated electrodeposition processes replace the conventional complicated chemistry approach by eliminating the adverse effects of hydrogen, allowing plating from a non-toxic, additive-free Cr(III) bath. This process provides comparable thicknesses, plating rates, and current efficiencies, and equivalent hardnesses compared to conventional hexavalent chromium deposits. This process is applicable to other replacement coatings, such as Zn-alloys and cyanide-free gold.