The following question comes up again and again: "Can you mark aluminium in black with the laser?" Similar to black annealing markings on steel? " From now on, we can answer these questions with "YES". Assuming that the aluminum is anodised. The MOPA laser with variably adjustable pulse durations (between 4 and 200 ns) makes this application possible.
Especially natural anodised aluminium can be very well laser-marked in different gray tones up to a rich black. The conventional fiber lasers with relatively high pulse durations can engrave or ablate the anodised layer very well. Depending on the color of the layer, this results in a good contrast and a nice, bright engraving. However, this contrast is hardly visible on silver or natural anodised aluminium.
The special feature of the markings with the MOPA laser is that the surface is barely damaged or removed by shorter pulse durations. The coating (anodised layer) is only redyed. Although this is a completely different process from that of annealing marking of stainless steel, it produces a similar result.
High-quality smartphones, e.g. the Iphone are laser-marked in this way. Anodised layers in all other colors can also be marked in black with the MOPA laser. In combination with conventional laser engraving, there are more possibilities for marking anodised aluminium products.
All laser systems of the SpeedMarker series are now also available with MOPA Laser. Depending on the requirements and the application, you can choose between laser workstations in different sizes, a table marking station or an open class 4 system.
However, marking aluminium in black is only one application example where the MOPA laser can display its strengths. Even when marking steel or laser marking numerous types of plastics, the all-rounder scores points against conventional fiber lasers.