Laser Marking of Metals
Different Marking Methods
Depending on the requirement profile, different laser marking methods are available.
- Laser annealing is used with all metals which show a color change when exposed to heat and oxygen. The laser marker selectively heats up small spots of the workpiece surface until annealing colors appear. Annealing leaves the material surface unharmed but still produces high-contrast, clearly legible markings.
- Blackmarking is a solution for direct marking of stainless steel alloys. The ultrashort-pulse laser technology doesn’t introduce any significant heat and produces a high quality, high contrast mark regardless of the viewing angle. The process is particularly suitable for the implementation of the Unique Device Identification (UDI) in the medical industry, as well as for blackening of anodized aluminium surfaces and interesting for EMS-providers.
- Usually the laser marker engraves the material surface down to some 10 µm in depth. Engraved marks are exceptionally durable and can only be removed by heavy grinding. Therefore laser engraving is used for forgery-proof product marking.
- Selective ablation of lacquer coats or anodizing layers shows a different-colored material underneath and produces colored markings.
Features at a Glance
- Durable, high-contrast markings
- Intact surfaces (annealing), important e.g. for medical devices
- Fast compared to mechanical marking techniques
- Very small line widths realizable
- Flexible, individualized marking content