The example shows laser marking black anodised aluminium. Removing the anodising creates high character contrast ideal for this application.
Anodising explained
Anodising is an electrolytic passivation, widely used across industry on aluminium for a variety of reasons. The process offers a range of colour variations through the use of colour dying. The process changes the microscopic texture of the aluminium by modifying the crystal structure near the surface.
Laser marking black anodised aluminium, provides the highest contrast to the characters. In this example, we have used an Nd:YAG laser to vaporise the anodised surface exposing the host material.
Each block adds details to the use of each inlet/outlet facility for the engineers that will install at site.
Aluminium corrosion
The general consensus is, as the laser removes the anodised layer an oxide layer, very quickly forms to the surface, providing protection to the material beyond the oxide layer thickness, preventing corrosion.
How to achieve good results
To achieve consistent white marks on aluminium, you need the correct laser power, repetition rate, marking speed and image fill ratio. With most aluminium’s a slight deviation, either way, from your standard settings should be enough to pull back any variation you see. In some cases, it may also be worthwhile considering a second pass with much lower power settings to lightly skim the image, removing any burning caused by the initial process pass.
If you would like further information on this laser marking application, or any other application, please request a call back or talk to one of our laser marking specialists on 01737 826902.
