The Platinised Titanium and Niobium anodes are used as insoluble anodes in modern electroplating baths for hard chromium plating of rotogravure cylinders and piston rings etc. Chromic acid solutions, which are containing Sulphuric acid, are used as electrolyte.
For hard chromium plating of rotogravure cylinders or piston rings - our semicircular, anodes are very well adapt to the cylinder shape cathodes. In principle, there are different types of anodes are used with one or two bows.
The platinum layer is produced of molten platinum salt by means of the procedure up to 20micron thick. The platinised titanium or Platinised niobium (if the bath contain higher rate of fluorides), will perform…
Dense crystalline layer structure and thereby good mechanical properties; Even metal distribution of the platinum layer and optimal adhesion of the ti mesh; Long lasting (approx 8 g platinum per 1 million Ah are removed per bath) and dimensionally stable; the base material or substrate is reusable after re-plating. No maintenance of anodes necessary; Constant conductivity of the anodes; Very short distance from the electrode to the articles (cylinder - 4-6 cm.). Chrome plating is essentially faster and a chrome layer is very even (cause an even current distribution and enable the use of a higher current density), due to the constant electrolyte flow through anode mesh.