Chromated layer as an Anti‐tarnish protection of AuAgCu alloys

摘要

AbstractThe electrochemical chromatation was carried out on a 14 ct AuAgCu alloy used in decorative applications as an anti‐tarnish treatment. The influence of the electrolyte composition and deposition parameters was studied. The tarnish resistance of the chromated layer was investigated in particular with respect to a previous mild abrasive treatment. Auger Electron Spectroscopy was used to estimate the thickness of the film as a function of the chromatation time. The chromated layer does not change the aspect of the alloy and provides a very efficient protection against tarnishing. It is very thin and does not withstand the abrasive effect of a polishing cloth commonly used by the jewellers. By contrast, it can be cleaned in isopropanol without any decrease in its tarnish resistanc