Umicore: New cobalt- and nickel-free hard gold plating

The new Auruna gold-iron alloys from Umicore, a leading provider of metal deposition solutions, combine the precious, soft gold with the base, robust iron to form a perfect final layer. This combination is not only aesthetic and functional, but also more sustainable and economical than conventional hard gold compounds with cobalt or nickel. The Auruna product range offers an excellent alternative to traditional hard gold alloys and enables customers to make their processes more environmentally friendly and safer. Traditional hard gold alloys contain cobalt or nickel, which poses significant environmental, health and safety (EHS) risks. The extraction and processing of these metals is ethically problematic and subject to strict regulations. In addition, their processing requires high safety standards to minimize health risks. These growing challenges have prompted Umicore to develop an innovative solution that addresses these issues while meeting the highest quality standards.

Advantages of the new Umicore Auruna gold-iron alloys

One of the advantages of the new Auruna product range is conflict-free sourcing: unlike cobalt and nickel, iron is conflict-free and available in large quantities. This reduces dependence on problematic raw materials and contributes to a more ethically correct and significantly more traceable supply chain. Companies can thus position themselves as responsible players and at the same time reduce bureaucratic hurdles to a minimum. Iron is cost-effective and does not require expensive safety standards during processing. This enables customers to reduce their production costs and improve the safety of their processes at the same time. Cobalt and nickel-free sourcing and production reduces environmental issues associated with resource extraction. Umicore is committed to environmentally friendly and responsible production and supports its customers in achieving their sustainability goals. In addition, the new product has excellent layering properties: Auruna electrolytes produce crack-free, ductile and low-porosity layers that are highly resistant to abrasion and chemical attack. This ensures a long service life and high reliability of the coated products.

Auruna 313, Auruna 5300 and Auruna 215 (Pale)

The new Auruna 313, which forms the basis of the product range, is based on the Auruna 311, which has been successful on the market for over 40 years, and is in no way inferior to it. Like its predecessor, the halide- (chloride- or fluoride-), nickel- and cobalt-free Auruna 313 is the first choice for the direct gold plating of stainless steels that are difficult to activate (e.g. chromium-nickel steels, molybdenum-containing steels or nickel-based alloys) and other passive materials. This innovative solution enables customers to achieve high-quality and durable coatings that meet the highest requirements. Auruna 5300 was specially developed for barrel and rack operation and enables RoHS-compliant coatings. This makes it particularly attractive for decorative applications such as jewelry and writing instruments, not only because of its nickel- and cobalt-free and therefore allergen-free coatings. Alternatively, this gold-iron electrolyte can also be used for technical products. Auruna 215 is an exceptionally color-constant variant. The deposition color (1N - 2N) is independent of pH value and current density over a wide working range. Due to the addition of indium, there are no color nuances even with different production batches. This electrolyte is also available in a very elegant-looking, pale yellow (1N) version as Auruna 215 Pale. Umicore Metal Deposition Solutions plans to continuously expand the Auruna product range to meet the growing demands and specific needs of its customers. "For special scenarios or requirements that call for an electrolyte that meets industry standards (e.g. ASTM standards), is cost-optimized, faster or deposits with higher layer thicknesses, we have planned further gold-iron electrolytes in the portfolio," says Martin Stegmaier (Division Manager for PGM and decorative precious metal applications), describing the current research activities on the product range.