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Chromium Plating - Technology - Scionix PDF Print E-mail
Environmentally benign chromium electroplating process.
Chromium Plating
A significant difficulty is the coating of metal objects with chromium for anti-corrosion, anti-wear or decorative purposes. Currently the technology uses chromic acid, a substance so hazardous that it is banned from the majority of processes. EU and US is seeking to limit its industrial use through legislation, but the lack of an alternative methodology has delayed its implementation. Scionix Ltd has developed a method of plating chromium from environmentally sustainable ionic liquids that should be recyclable and which significantly decrease toxic emissions.
Process Features:
  • Current efficiency increased (from 10-20% to >90%)
  • Use of trivalent Cr ions (in situ generation from Cr)
  • No chromic acid vapours produced
  • Plating of aluminium/titanium possible
  • No hydrogen evolution
  • No aqueous or organic solvents used
  • Ionic liquids can be reused/recycled with minimal loss
  • Potential to keep existing electroplating equipment
Ionic liquids are particularly beneficial because not only do they replace the hazardous plating solution, but they also allow a considerable increase in the electrochemical efficiency of the process thus saving energy. Furthermore, the working conditions for operators are also dramatically improved. Scionix has also developed ionic liquids for the electrodeposition of a wide range of other metals and alloys.
We have now developed a method to deposit thick (up to 20 micrometer), adherent, crack free chromium black onto a wide range of metal surfaces (including aluminium) with a high current efficiency.