Blackening is achieved by rapidly raising the temperature of the material through the laser and then quickly cooling it down, which is commonly referred to as tempering. The key is to control the energy input.

As for how the laser marking machine can produce a black effect on the material, there is no fixed method for this. Because the purity of the material is different, the type of laser light source used is also different, and the parameters are also different. The color depth is related to the marking speed, frequency, current size, density, and laser power. As long as one link is not in place, The effect of typing will be completely different.

For example, stainless steel is used for blackening, using optical fibers or semiconductors. Generally, defocusing is used for blackening (defocusing, slow speed, high power). Defocusing makes the spot larger and the spot overlap rate increases, making it easy to achieve tempering. Positive focus can also be used, high frequency fiber can be used, energy density is reduced, overlap rate can also be guaranteed, and tempering can be achieved.

To black out the alumina material, the MOPA machine is used. The mopa laser engraving machine has a wide pulse width and pulse frequency adjustment range. The narrow pulse width and high frequency parameters can produce black effects of different depths on the surface of the alumina material. Fine and beautiful, no less than silk screen printing.

Part of the plastic material is blackened, and the UV laser marking machine is used, etc.

PS: Blackout is more time-consuming, good parameters can improve efficiency.

Related article: "Main Factors Affecting Alumina Laser Blackening"