The Research Of Decorative Chromium (â…¢) Electroplating Process

As an important part of electroplating industry——hexavalent chromium plating, caused a growing environmental pollution in recent years, attachend lots of people great importance to the promotion to replace hexavalent chromium plating. Trivalent chromium plating process due to its good dispersion and coverage capacity, aroused the attention of workers in electroplating; but the current trivalent chromium plating coating gloomy exist, poor bath stability, making it a place electroplating workers in the face of a difficulty.In this paper, we use Hull cell to explore the composition of trivalent chromium plating solution concentration and its composition, combined with orthogonal experiments, the bath to finalize the optimum proportion of each component. We found complexing agent A can significantly increased the brightness at this system. Meanwhile, the effects of temperature, pH, current density and plating time etc. on chromium coating brightness and growth rate and other properties of the law and determined the conditions suitable for industrial production.In addition, from a more comprehensive industry assessment index, we compare trivalent chromium plating with chromium plating for traditional. The results show that chloride chromium electroplating system to plating out bright, uniform, combined with strong, good corrosion resistance coating, and also with increasing degree of coating speed, high current efficiency, good dispersion and coverage capacity, effective current density width and so on. This experiment also applied the self-made Ti/Ru-Ti-Sn as the anode, the results showed that this electrode not only comparable with the traditional graphite anode, and a simple preparation, chemical stability, the most important is the analysis of low chlorine evolution potential, anode fewer side effects, make the bath more stable.According to SEM result, we found that under high current density of trivalent chromium coating showed a lot of cracks, and small current density of these cracks disappear, the coating surface was spherical, and the low current density plating to repair cracks in the function. XRD experiments confirmed that this system has been the coating is non-crystalline form, the crystal-like coating corrosion faster, so its confirmed the trivalent chromium plating corrosion rate lower than the hexavalent chromium causes. The research system for further study of trivalent chromium electroplating process and the industrialization provided reliable experimental data.