RHODUNA®-Alloy Black 1 is probably the only alloy to combine all the properties required of a dark precious metal surface.  Abrasion resistance, an attractive price and, of course, a sophisticated and adjustable shade of black are surely the most important features.

Dark precious metal alloy with impressive properties

Black rhodium is only of minimal interest to most mass producers due to the high price of the precious metal. Black ruthenium is only suitable for everyday objects due to its low abrasion resistance and slightly brown tone. RHODUNA®-Alloy Black 1 combines both metals in equal parts into one electrolyte without the negative properties of either.

A real milestone in surface finishing

The elegant RHODUNA®-Alloy Black 1 alloy exceeds previous expectations of a dark precious metal coating, so is a real milestone in surface finishing.

Especially in mass production, the incredible color consistency of the sophisticated dark anthracite stands out - differences from the set black shade cannot be recognised with the naked eye. This applies whether the coating is glossy or matt.

Adjust the degree of blackness up to a deep black final layer

The degree of blackness is limited in the favor of color consistency and easy handling of the electrolyte. If a darker or completely black final result is desired, we have you covered. RHODUNA®-Alloy Black 1 is ideal as an interim coating for RHODUNA® Black 471. This lets you adjust the degree of blackness up to a deep black final layer to meet your needs.

Jewelry, plug contacts, writing implements, bathroom fittings or even car interiors can now be given a finish in the black shade of your choice.

Fulfils all requirements for a dark precious metal surface finish

Sophisticated anthracite without compromise

The sophisticated look of the final layer is not a matter of luck. Up to now, the degree of black was adjusted by current. With RHODUNA®-Alloy Black 1, this is no longer needed thanks to almost perfect color consistency. The result is an almost unknown consistency of the L* value (L*a*b* color space) through standard current strengths - so shade deviations are mostly prevented during production and during any follow-up batches.

For optical color neutrality, you need a* and b* values under 1 in the L*a*b* colour space. This can be realised for a* for many dark layers, but b* under 3 is almost impossible. Yellow and brown shades are the result.

With an average b* value of 0.6 above the standard currents strengths, RHODUNA®-Alloy Black 1 displays no discolouration that can be seen with the naked eye.

Incomparable abrasion resistance for dark precious metal layers

Maximum layer removal of just 0.2µm or 0.63mg (measured using Bosch-Weinmann) is another USP of RHODUNA®-Alloy Black 1. Compared with black rhodium or ruthenium electrolytes, the results are four times better.

This abrasion resistance promises a long life for your coated product, and can be compared to that of abrasion-resistant light rhodium layers.

Cost savings of almost 50% compared to a pure rhodium electrolyte

Due to the 1:1 ratio of rhodium and ruthenium, the electrolyte is not just extremely easy to use but also provides financial benefits.

Ruthenium has almost always had a very stable and comparably low price. The price of rhodium, on the other hand, has almost quadrupled within two years. Thanks to the composition of the electrolyte, a saving of 45% or more is realistic compared with a pure rhodium electrolyte.