Laser Marking Parameters for Anodized Aluminum: From Novice to Expert

The book provides the core parameter settings for laser marking of anodized aluminum, and discusses key issues such as power, speed, and frequency. The book also provides practical solutions to common problems, and helps users master the strategies for parameter adjustment, from the basic to the advanced. It also helps to improve marking efficiency and product quality.

Why does the setting of parameters decide the success or failure of marking?

Laser marking of anodized aluminum is like cooking a dish--the parameters must be carefully set, or the product will be overcooked or undercooked.Our master technicians in the factory say, "No matter how expensive the machine, if you don't know how to adjust the parameters, it's all for naught.The aluminum oxide surface layer in particular is very sensitive to laser light, and too high a power can burn through it, while too low a frequency can leave it with a wavy surface.

These three parameters are the basic building blocks.

The more power, the better.

Newcomers often make the mistake of cranking up the power to the max.In fact, 30-50 % power is sufficient for marking aluminum oxide. For example, for a 0.03-mm-thick plate, with a 35-W fiber laser, the safest setting is around 40 %.A good rule of thumb is to use a power setting equal to the thickness of the material in millimeters multiplied by 1000. So, for example, for 0.8mm material use 80 % power.

The speed of the brush must follow the pattern.

Simple text can be printed at 800mm / s, but when a complex logo is encountered, the speed must be reduced to 500mm / s or less.A clever way to find the right speed is to first try a test print on scrap material. Set the speed so that the outline of the pattern can be seen, and then increase it by 10 %.

If you tune the frequency correctly, you'll save energy.

The 20-kHz frequency is the most commonly used, but for the fade-in effect you have to use pulse mode.One client did an experiment: for every 5 kHz increase in frequency, the depth of coloration of the oxide film increased 0.02 mm, but the risk of burning also doubled.So the most reliable way is to use 20-30 kHz for conventional signs.

Advanced adjustment techniques.

Don't forget depth of field.

Many people don't know that the best results are obtained when the laser head is 2-3mm away from the material.In our factory, we prepare spacers of different thickness for testing, with 0.5 mm spacers for thin plates and 1 mm for thicker workpieces. This little detail can improve the clarity of the edge by 30 %.

The auxiliary gas is also important.

Don't underestimate the pressure of compressed air, which is best in the range of 0.2-0.3MPa.One manufacturer adjusted the pressure from 0.25 to 0.28 MPa, and the problem of carbon deposits on the surface of the aluminum oxide disappeared.Remember to clean the air filter every month.

You have to monitor the temperature.

When the temperature in the workshop exceeds 28 degrees in the summer, it is recommended to reduce the power by 5 %.Last year during the hottest days of summer, the marking machines in our factory kept sounding alarms. It turned out that the laser power output was fluctuating because the cooling system was inadequate.Now every workstation has its own thermometer, and as soon as the temperature rises above 26 ° C, the cooling fan switches on.

One solution to a common problem.

If the color is uneven, check the surface of the wood to see if it is flat, and if not, wipe it down with alcohol.The most likely cause for the yellowing is that the frequency is too high. Try setting it at 5kHz.Most of the time, the problem is that the focal length is not quite right. Adjusting the focus can solve 80 % of these problems.Remembering these emergency measures can save you a lot of trouble.

(For specific parameters and case studies, see the accompanying charts and photos.)