Precious metal SLM produces fully dense, hallmark-compliant gold and platinum parts directly from CAD without wax patterns, molds, or casting sprues. The process is selective laser melting using 15–25 µm precious metal powder — finer than industrial DMLS powder to achieve the resolution jewelry requires.
Available Precious Metal Alloys
Gold:
- 18K yellow gold (75Au-12.5Ag-12.5Cu) — warm color, standard for fine jewelry
- 18K white gold (75Au-12.5Pd-12.5Ag) — palladium white gold, no rhodium plating required
- 18K rose gold (75Au-22Cu-3Ag) — pink color, increasingly popular
- 14K yellow (58.5Au) — lower cost, good for fashion jewelry
Platinum:
- Pt950 (95Pt-5Ru) — highest purity, hypoallergenic, exceptional luster
- Pt950 (95Pt-5Co) — slightly harder, better wear resistance
Silver:
- 999 fine silver — for art objects and fashion jewelry; lower melting point aids printing
Design Guidelines
Minimum wall thickness: 0.3 mm (gold), 0.4 mm (platinum — higher thermal conductivity) Minimum feature size: 0.2 mm resolution, 0.1 mm achievable on detail Support structures: Required below 30° for gold; 45° for platinum Hollow forms: Minimum 2 powder evacuation holes (≥ 2 mm diameter) required
Cost vs. Casting
Precious metal powder costs $80–$300/gram depending on alloy and gold content — comparable to casting grain. DMLS build waste (support structures, failed powder) is recyclable. The cost premium over casting is process time, not material. For unique and complex pieces, DMLS eliminates the mold tooling cost ($500–5,000 for injection wax molds).