Steel versus aluminum: How do you adjust the parameters for different materials?

The company provides specific parameter adjustment suggestions for laser engraving on two commonly used metals, stainless steel and aluminum alloy, including power, speed, and frequency. This helps operators quickly optimize engraving results.

Why is it that different metals require different parameters?

The effect of laser marking is closely related to the characteristics of the metal material.For example, stainless steel is hard and slow to conduct heat, while aluminum alloys are soft and have a high reflectivity. These two materials have completely different absorption rates and reactions to laser light.If the same parameters are used to engrave the same design on both, the result will be either a blurred mark or damage to the surface of the material.We have to get to know their "dispositions" first, then adjust the machine accordingly.

How do you set the parameters for marking stainless steel?

Stainless steel is commonly used for industrial parts and nameplates, for which a clear, durable mark is desired.Here are some key points to share:

Be generous with power, but cautious with speed.

Because stainless steel has a high hardness, it is generally recommended that the laser power be adjusted to 70-90 percent (using a 20-watt fiber laser as an example).The speed is controlled at between 500-800 mm / s. If it goes too fast, the oxide layer will be uneven and the mark will be gray. If it goes too slowly, it might burn a hole.

Choose the middle frequency.

A frequency setting of 20-50 kHz is more reliable.High-frequency lasers are suitable for fine text, while low-frequency lasers can deepen the marking.If the workpiece tends to rust after marking, you can try raising the frequency and lowering the power, which will reduce the heat-affected zone.

How do you set the parameters for marking on aluminum alloys?

The biggest headache in marking aluminum is the problem of reflectivity. If the parameters aren't set properly, the mark will either appear black, or simply disappear.Just remember these three things:

Power output will rise over time.

First, try 30-50 % power. If the color of the mark is too light, increase the power by 5 % steps.In particular, if the power is too high, it can burn through the surface coating of anodized aluminum, revealing a less-than-appealing white base.

You have to dare to increase the speed.

The speed is suggested to start at 1200mm / s and can reach as high as 2000mm / s.Don't be afraid to go fast--aluminum conducts heat quickly, so raising the speed of the lathe actually helps to prevent deformation.With low power, the edges of the mark are even cleaner.

Add an assist gas.

If conditions permit, adding compressed air can effectively improve the problem.The air pressure doesn't have to be too high, 0.2-0.5MPa is sufficient, mainly to blow away the metal steam and debris produced by the laser.

Practical tips.

1. Test the parameters on scrap: The composition of materials from different manufacturers is different, so before you start engraving, you must do a step test.

2. After marking, stainless steel can be wiped with alcohol to increase the contrast.

3. Don't forget about the humidity: Especially when marking aluminum, a humidity of over 60 % can cause the formation of water droplets that interfere with the laser.

Adjusting parameters according to these considerations can handle 90 % of the marking needs for stainless steel and aluminum alloy.If you come across special alloys, check the composition chart first. The parameters for high magnesium aluminum alloys and molybdenum stainless steel must be adjusted.