With a MOPA laser source, you can set very short pulse durations. This is the secret to creating black marks on anodised aluminium, as the short pulse durations do not damage the surface of the material. The anodised layer is not removed, simply repainted. Whilst the process of black marking is completely different from the production of tempering colours on stainless steel, a comparable result is created. You can set the filling line distance to adjust in a wide range of various shades of grey up to black: The smaller the distance, the darker the laser marking result.
To create a black mark on anodised aluminium, you need a 20 watt MOPA laser source. We recommend using the F-254 lens because it perfectly fits the spot diameter for this application. You should set the following parameters:
|50%||1500 mm/s||200 kHz||8 ns|
|Focus||Filling lines distance||Passes|
|In focus||0.001 mm bidirectional for a rich black |
0.002 - 0.005 mm bidirectional for grey tones
It is important to remember that the anodised layers can be very different. Always use the engraving page for black marking. If you have further questions, our experts from the application laboratory will be happy to help. To ensure that the parameters we specify work, we recommend that you purchase anodised aluminium from webshop.