The image shows a selection of anodised aluminium components, that are used as cable tidies on very expensive music system cable looms by our customer Dynamique Audio. Laser marking anodised aluminium onto curved surfaces is common practice. This electrolytic passivation is widely used across industry on aluminium for a variety of reasons. The process can also provide a huge 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 anodised aluminium on curved surfaces such as these, can achieve extremely good results.
Laser marking anodised aluminium onto curved surfaces
Due to the laser beam being focused, movement away from the focal point causes two issues. The first is, energy density changes and the second is spot size change. Both of these are directly linked to each other. In order to ensure that neither of these effect the mark quality, two things have to be part of the set up. The image must remain within a 20 -25 degree segment, on the diameter and the focal position must be set half way between the higher and lower point of the image. Sounds complex, but it is rather straight forward. Staying within the segment mentioned, ensures there is no character deformation due to the curved surface.
Each of the components is made up of two parts, which when clamped together, they hold the various cable configurations in place. Each of the units in the designed range, has a different name for identification, and the branding is also used to create brand awareness for the customer. In this case, an Nd:YAG laser is used to remove the anodising and expose the base materials, in this case aluminium. The high quality aluminium, provides a high contrast marking surface to work with, resulting in a quality mark.
The combined precision of the beam placement along with our tooling design, means the part and mark are precisely aligned every time we set up a new batch. Your files are saved, and held for as long as you wish to work with us.
CO2 laser marking anodised aluminium onto curved surfaces
CO2 lasers can also be used to process anodised aluminium. In this laser marking process, it is the dye that is directly affected rather than the material. The energy from the laser marking creates a heating action that removes the dye from the surface. The use of CO2 is generally not as well received as Nd:YAG, due to the lower quality created by the mark process. This is directly related to the fact that the heating effect is difficult to control due to “heat creep”. The result is a fuzzy edge to the mark image and not as crisp as with Nd:YAG. The main advantage is, no material is removed leaving the anodising closer to its original state, and per unit cost will be slightly higher with CO2, due to the process time being slower.
If you would like further information on this application, or any other application, please request a call back or, talk to one of our laser marking specialists by going to our contact page – link below.