Laser Marking Machine for Alumina Black Marking

Recently, many customers have inquired whether alumina can be blackened. Alumina blackening is possible. The mechanism of anodized aluminum blackening is to use a focused high-energy density laser to change the thickness of anodized aluminum to 5-20um in a short period of time. The layer further oxidizes and changes the mechanism of the surface material.

The principle of aluminum blackening is based on the nano-effect. Because the size of the oxide particles is nanometer level after laser processing, the light absorption performance of the material is increased, so that visible light is irradiated to the material and absorbed, and the reflected visible light is very small, so that it can be observed by the naked eye. It must be black, so it is called alumina black.

The thickness of the oxide layer of anodized aluminum and the surface treatment process. Generally speaking, the thickness of the film is 5-20um. The thickness of the film directly determines the effect and efficiency of blackening. Generally, the thickness of the film is 10-20um, which is easier to blacken. When it is less than 8um, the oxide film is too thin, easy to break, and white spots appear, which needs to be compensated by laser parameters. In addition, the anodized aluminum surface treatment process will directly affect the blackening effect. Sandblasting and surface drawing are common processes. The thickness of the sandblasting will have different effects on the marking effect. The finer the sandblasting particles, the better the blackening effect. . It is recommended that the film thickness of anodized aluminum be 10-15μm, so that the overall blackness effect will be better.