Cobalt- and nickel-free hard gold plating in unique quality
Metal Deposition Solutions
Gold and iron together form a perfect layer
The yin-yang symbolism, which describes the balance and harmony between two opposing but complementary forces, can be wonderfully applied to our new AURUNA® gold-iron alloys.
They combine the precious, soft gold and the non-precious, hard iron to form a perfect, complementary final layer. The combination of both elements is aesthetic, functional, robust and, above all, more sustainable and therefore more economical than the previously predominant hard gold alloys with cobalt or nickel.
Previous hard gold alloys confront EHS teams with major challenges in procurement and production
Common hard gold alloys contain cobalt or nickel. This means that they are increasingly challenging for EHS (Environmental, Health, and Safety) teams. The sourcing and processing of cobalt and nickel involves significant risks and ethical issues - resulting in increased regulation. However, the use of hard gold alloys is unavoidable for a wide range of decorative applications and for many technical achievements.
High safety standards in production
According to the European Chemicals Agency (ECHA), the processing of nickel and cobalt, especially if not handled properly, carries risks that can lead to serious health problems (including cancer, respiratory diseases, fertility problems and possible genetic defects). Therefore, strict safety standards must be introduced to minimise exposure to nickel and cobalt dust and vapours. These include regular training, protective equipment and monitoring of the working environment.
No guarantee of conflict-free procurement
The conflict-free sourcing of cobalt is a key problem with gold-cobalt alloys. Much of the cobalt is mined in regions affected by political unrest and human rights violations (very poor working conditions, exploitation, child labour), such as the Democratic Republic of Congo. Here, companies must ensure that their supply chains are not affected by conflict or human rights violations. This requires strict controls and transparency along the entire supply chain.
Environmental concerns and direct impacts
Cobalt and nickel mining is often associated with significant environmental damage. This includes the destruction of habitats, the pollution of water sources and the release of particulate matter, harmful heavy metals and sulphur dioxide into the environment. These environmental impacts can have long-term consequences for the local population and biodiversity. The processing of cobalt and nickel also requires large amounts of energy and water, resulting in a high ecological footprint.
Sourcing and producing cobalt and nickel-free products not only offers environmental and ethical benefits. By reducing health and safety risks, companies can also save costs in the long term and increase their operational efficiency. Furthermore, companies can better achieve their sustainability goals and position themselves as responsible players. This strengthens consumer trust and can lead to higher market demand.
AURUNA® - the perfect symbiosis of gold and iron reflects the yin-yang philosophy: two different elements create a harmonious and functional whole.
Our customers confirm that our existing hard gold processes, which are based on critical alloying partners, are second to none in terms of quality and ease of use. The top priority in the intensive research we have conducted to modify our established AURUNA® electrolytes was to maintain the high quality level in all properties.
High-quality, unrivalled and yet sustainable hard gold coatings
The new alloying partner iron makes us forget the above-mentioned negative aspects of cobalt or nickel. Iron is conflict-free and, in contrast to nickel and cobalt (due to the steadily increasing use for battery materials in electric mobility), it is available in large quantities and therefore cost-effective. In addition, iron does not require expensive and elaborate safety standards during processing, as is the case with nickel and cobalt.
The handling and plating properties have not changed despite the changeover. AURUNA® electrolytes are therefore still the best choice for all hard gold applications and can be used 1:1 like our previous products.
The successor product AURUNA® 313 is the perfect upgrade to AURUNA® 311, which has been a market success for over 40 years. On the contrary: like its forerunner, the halide (chloride or fluoride), nickel and cobalt-free AURUNA® 313 is the first choice for the direct gold plating of difficult-to-activate stainless steels (e.g. chromium-nickel steels, molybdenum-containing steels or nickel-based alloys) and other passive materials.
We are opening a new chapter in direct gold plating with AURUNA® 313!
The new electrolyte can replace its forerunner in every respect – which is not surprising, since the advantageous electrolyte and layer properties have been successfully retained. This gives the user the assurance that, despite the change of alloy partner, he is essentially using a proven product that meets the highest standards.
In addition to glossy and gloss-retaining layers, AURUNA® 313 is also characterised by an extraordinary longevity. This results, on the one hand, from the well-adhering direct gold plating, which makes non-precious and thus corrosion-prone metallic intermediate layers unnecessary. On the other hand, the layers are crack-free, ductile and low in pores up to a thickness of 0.5 µm, which enables high resistance to abrasion and chemical attack.
The highly effective, strongly acidic gold electrolyte offers a wide operating range and thus easy handling in all common forms of application (rack, barrel and reel-to-reel). It can therefore be integrated into all common process sequences without hesitation.
AURUNA® 313 is the blueprint for the conversion of other electrolytes
AURUNA® 313 is universally applicable for both decorative and technical applications. However, we have planned further gold electrolytes in our portfolio for special scenarios or requirements that demand an electrolyte that meets an industry standard, is cost-optimised, faster or can be deposited in higher layer thicknesses. The first variant, AURUNA® 5300, is already available.
The cost-optimised hard gold variant AURUNA® 5300 was specially developed for barrel and rack plating and enables RoHS-compliant coatings. This makes it particularly attractive for decorative applications such as jewelry and writing instruments, not only because its layers are nickel- and cobalt-free and therefore non-allergenic. This gold-iron electrolyte can, of course, also be used for technical products.
In the decorative market segment, particularly in jewelry, a very even colour distribution is required. The weakly acidic gold-iron electrolyte AURUNA® 215 is easy to use in both rack and barrel plating and, thanks to the addition of indium, has a very constant colour. The deposition colour (1N - 2N) is independent of the pH value and current density over a wide working range and therefore does not show any colour nuances even across different production batches.
The weakly acidic gold-iron electrolyte AURUNA® 215 Pale is a further development of the well-established AURUNA® 215. Thanks to modified parameters, it is now possible to achieve a very elegant, pale yellow colour tone (1N). All other electrolyte and layer properties are almost identical and enable an unrivalled colour consistency of the decorative final layer in both rack and barrel operation.
Expert advice from the start for a successful switch to a responsible plating
Let us identify together which AURUNA® variant is best suited to your specific requirements. We will work with you to find the optimal process that can be adapted or replaced at any time as conditions change.
We are guided entirely by your needs and look forward to supporting you on your journey towards a quality-conscious, sustainable and responsible plating.
![Umicore MDS - AURUNA - Cobalt- and nickel-free hard gilding - 313](data:image/svg+xml,%3Csvg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 575 382"%3E%3C/svg%3E)
