Additive manufacturing of precious metals
3D printing of platinum and 18K gold for haute horlogerie and medical technology.
1. Introduction: High-tech meets pure luxury
When you think of industrial 3D printing, you usually think of turbine blades made of Inconel or knee implants made of titanium. But in the shadow of these giants, a highly specialized niche has developed: powder bed-based 3D printing (PBF-LB) of precious metals such as 18-carat gold (red gold, white gold, yellow gold), 950 platinum and sterling silver.
For the jewelry and watch industry, this means a paradigm shift that combines handcrafted goldsmithing with the absolute geometric freedom of additive manufacturing.
Why not water in the classic way?
Classic investment casting (lost wax process) reaches its limits when it comes to interlocking links (such as movable chains that are printed "in-situ"), microscopic lattice structures or cavities. 3D printing makes it possible to fill a solid gold bracelet completely hollow inside or with a super light lattice structure, which saves massive weight (and therefore pure material costs).
2. Powder handling: When dust is worth millions
The biggest challenge in precious metal printing is not the printing process itself, but the economics of the powder.
- The value in the installation space: A normal PBF system holds dozens of kilograms of powder. With 18K gold, this means a material commitment worth hundreds of thousands of euros. Special precious metal printers (e.g. from Sisma or Concept Laser) have extremely small installation spaces (e.g. 50x50 mm) and optimized coating systems (recoaters) that only apply minimal amounts of powder per layer.
- Recovery (recycling): Every grain of dust is cash. The machine's filters, the brushes for depowdering and even the suction water are elaborately processed (divorced) in order to recover almost 100% of the gold or platinum that has not been melted.
3. Metallurgy of gold and platinum in laser focus
The laser parameters must be tuned extremely precisely because precious metals are physically demanding.
- Gold: Gold has a very high thermal conductivity and - especially with infrared lasers - an extremely high reflectivity. The laser must be shot with a very fine focus and high power into very small melt pools in order to melt the gold in the first place.
- Platinum: Platinum is the exact opposite. It has a high melting point (1,768 °C), low thermal conductivity and absorbs laser light very well. It is almost easier to print than gold, but carries the risk of heat build-up. Platinum printed parts have a hardness that is hardly achievable with traditional platinum casting.
4. Areas of application beyond jewelry
Even if luxury watches and individual designer jewelry are the driving force, printed precious metals also have industrial relevance:
- Platinum in medical technology: Platinum is extremely biocompatible, radiopaque and very conductive. Printed platinum electrodes are used in pacemakers or neuromodulators (deep brain stimulation).
- Gold in electronics: Individual, microscopic high-frequency conductor tracks or contacts in high-end electronics where maximum corrosion resistance is required.
5. Conclusion: The digital goldsmith
Precious metal 3D printing is economically extremely complex as the amortization of the machine competes with the interest costs of the bound powder. However, if you master this process (optimized powder handling and perfect post-processing such as PeP for polishing filigree gold structures), doors open in haute horlogerie and the production of luxury goods that are impossible to cast.