RHODUNA® PT Rhodium-Platinum-Electrolyte

Irresistible – Rhodium with the allure of platinum

Rhodium creates a brilliant white surface on decorative products. Platinum has enjoyed an incredibly stable price for a number of years, and its name is desirable for all buyer groups. Imagine an alloy that combines the benefits of both precious metals.

A RHODUNA® PT layer is built up of rhodium and platinum one half each, notwithstanding that the high-quality alloy can not be distinguished from that of a pure rhodium electrolyte, even with a trained eye. Due to the high societal significance of platinum, your product also gains in psychological value and its price acceptance increases significantly – conversely, for you as a producer a coating with RHODUNA® PT is more attractively in price than that with a pure rhodium electrolyte.

Alternatively, the alloy composition of rhodium and platinum can be variably adjusted. Compositions of 80 % platinum to 20 % rhodium, and vice versa, are possible - and all this with constant layer properties. Therefore you always have the price advantage on your side.

Electrolyte characteristics

Electrolyte type - Strongly acidic

Metal content - 0,6 - 1,5 g/l Rh, 0,6 - 1,5 g/l Pt

pH value - < 1

Operating temperature - 45 (40 - 50) °C

Current density range - 3,0 (2,0 - 4,0) A/dm²

Plating speed - ca. 0,1 μm/min 3 A/dm²

Anode material - MMO (type PLATINODE® 187 SO)

Coating characteristics

Coating - Rhodium-platinum

Alloy composition - 20 - 80 % Rh, 20 - 80 % Pt

Colour of deposit - White

Brightness - Bright

Hardness of deposit - 600 HV (at 50 % Rh and 50 % Pt)

Max. coating thickness - up to 0,3 μm

Density of the coating - Approx. 15,7 g/cm³ (at 50 % Rh and 50 % Pt)

Advantages

• White and bright rhodium-platinum coatings
• Uniform layer thickness
• Crack-free up to 0,3 μm
• Wide current density range
• Abrasion-resistant
• Less expensive than pure rhodium layers
• Minor porosity and good throwing power
• Good covering speed
• For rack and barrel plating

Applications

• Jewellery
• Watches
• Writing implements
• Eyeglasses
• Fittings