How to Control the Depth of Laser Marking on Aluminum Oxide

He explains in detail how to precisely control the depth of the mark by adjusting key parameters such as laser power, frequency, and speed.By combining practical experience with analysis of the effects of different parameter combinations on marking results, they provide suggestions to help customers achieve high-quality, stable marking results.

Why does the laser parameter affect the depth of the mark?

Aluminum oxide is hard and resistant to corrosion, but these very same characteristics make it particularly sensitive to laser parameters.If the power is set too high, the material may burn. If the frequency is set too high, the mark may be too shallow. The combination of parameters directly determines the depth and clarity of the final mark.Don't rush to make adjustments; first read the analysis below.

What is the core parameter?

The choice of laser power.

The power is like the force of the engraver's chisel, and is directly related to the amount of energy absorbed by the surface of the aluminum oxide.For ordinary aluminum oxide boards, you can start with 30 W of power and gradually adjust the power up or down.A little trick: First make a step test using the scraps (e.g. 20W / 25W / 30W), and then compare them with your eyes.

The frequency and the speed must match.

The frequency determines the density of the laser pulses, and the speed affects how fast the laser head moves.If you want to go deeper, try the "low frequency slow speed" combination of lowering the frequency below 20kHz and controlling the speed under 300mm/s.However, if the frequency is too low, it will result in continuous ablation, and in this case the duty cycle needs to be adjusted to balance the effect.

The hidden role of depth of field.

Many people overlook the defocus parameter, but it is actually a treasure trove of possibilities. Properly adjusting the defocus (allowing the focus to be slightly below the surface of the material) can increase energy density, and is particularly useful in cases where deeper marking is needed.But it is important to control the depth. It is recommended that the depth of each cut not exceed 0.2 mm, to avoid burning through the material.

Parameter optimization.

First fix two parameters and then fine tune.

Beginners are advised to focus on adjusting power output while keeping frequency and speed constant.Once the lowest effective power that does not cause yellowing is found, the frequency is adjusted in 5-kHz increments, and finally the speed is fine-tuned.This way it is not so easy for things to get out of hand.

Environmental factors should also be considered.

Remember to consider the temperature of the environment--when it's hot in the summer, the alumina cools slowly, so the actual energy used is higher than in winter, and you may need to reduce the power 3-5 %.

Take advantage of the pre-set mode.

The mainstream models now all have a special aluminum oxide mode, which is not a "stupid mode.These settings are actually safe parameter combinations set up by the manufacturer. They can serve as a starting point for adjusting the parameters, and then you can adjust the parameters according to specific needs. This can save half the time required for adjusting the parameters.

Quickly identifying common problems.

If you are having trouble with depth of field, check out these three things:

Is the laser lens dirty? (It should be cleaned at least twice a month.)

2. Is the cooling system working properly?

Is the surface of the material uniformly clean? (An oil film on the surface of aluminum oxide can cause uneven energy absorption.)

Remember that adjusting parameters is a delicate operation, and it's best to record the precise numbers and effects of each change.If you stick to doing the log, you'll be a veteran of the aluminum oxide marking business in three months!