RHODUNA®-Alloy is the first alloy electrolyte in the world combining the high-quality metals rhodium and ruthenium. The basic materials of the new coating are...
The first pure white electrolytic rhodium alloy
RHODUNA®-Alloy is the first alloy electrolyte in the world combining the high-quality metals rhodium and ruthenium. The basic materials of the new coating are truly royal: A mixture of rhodium, one of the world‘s most valuable precious metal, and the platinum group metal ruthenium.
Its white colour is absolutely equivalent to that of a pure rhodium layer. The electrolyte has all the quality characteristics of high-grade rhodium coatings and surpasses them in durability and uniformity. Its good throwing power even permits the plating of parts with complex geometries. It can be directly deposited on nickel, palladium, silver and gold.
At the same time, the "BrightQueen“ is considerably less expensive than pure rhodium layers.
Electrolytes Characteristics
| Electrolyte type | Strongly acidic |
| Metal content | 1.6 (0.8 - 1.8) g/l Rh 0.4 (0.2 - 0.5) g/l Ru |
| pH value | < 1 |
| Operating temperature | 45 (40 - 50) °C |
| Current density range | 4.0 (3.0 - 5.0) A/dm² |
| Plating speed | Approx. 0.2 μm/min at 4.0 A/dm² |
| Anode material | MMO (type PLATINODE® 187 SO) |
Coating Characteristics
| Coating | Rhodium-ruthenium |
| Alloy composition | 75 wt. % Rh, 25 % Ru |
| Colour of deposit | White |
| Brightness | Bright |
| Hardness | 600 - 900 HV |
Advantages
- Very light, white and ultra-bright coatings
- More uniform layer thickness
- Crack-free up to 1 μm
- Wide current density range
- Extremely abrasion-resistant
- Less expensive than pure rhodium layers
- Ideal for parts with complex geometries, e.g. chains
- Suitable for rack and barrel
Applications
- Spectacle frames
- Writing implements
- Jewellery
- Watches
