Cost-saving electrolyte for brilliant jewelry
With the strongly acidic alloy electrolyte PLATUNA®-Alloy RU, smooth, shiny and crack-free platinum-ruthenium coatings can be deposited up to a layer thickness of 0.5 μm. The deposited coatings are characterized by brilliant gloss and, in contrast to conventional platinum coatings, do not exhibit a yellow tint.
The advantage of the electrolyte is mainly the cost saving due to the ruthenium content. This is because ruthenium is still the cheapest metal among the platinum group metals. Furthermore, the electrolyte has a low sulfuric acid content and is therefore less aggressive to the coating substrate. The deposition rate is independent of the current density, which leads to an optimum layer thickness distribution. No precipitation occurs and the platinum concentrate does not have to be stored in the refrigerator.
Electrolyte characteristics
Electrolyte type Strongly acidic
Metal content 1.0 (0.8 - 1.2) g/l Pt, 1.0 (0.8 - 1.2) g/l Ru
pH value < 1
Operating temperature 60 (55 - 65) °C
Current density range 3 (0.5 - 10) A/dm²
Plating speed approx. 0.06 μm/min at 3 A/dm²
Deposition rate approx. 4 mg/Amin at 3 A/dm²
Coating characteristics
Coating Platinum ruthenium
Alloy composition approx. 80 % Pt, approx. 20 % Ru
Colour of deposit White
Brightness Bright, brilliant
Hardness not measurable, approx. 500 HV
Max. coating thickness approx. 0.5 μm
Density of the coating approx. 18.7 g/cm³
Advantages
Excellent brightness without yellow tint
Longer durability
High abrasion resistance
Current density independent
Easy handling - no cold storage and no precipitation
Applications
Jewelry
Watches
Writing implements
Spectacles frames
Bathroom fittings
