Alumina refers to a layer of dense alumina coated on the surface of aluminum and aluminum alloys in order to prevent further oxidation, and its chemical properties are the same as alumina. However, unlike ordinary oxide films, alumina can be dyed by electrolytic coloring. The MOPA laser marking machine produced by Foshan Fulan Laser is specially used for aluminum oxide blackening. It can also be used for stainless steel color marking, aluminum alloy blackening, stripping, stripping coating, semiconductor and electronic industries, plastics and other sensitive materials. Marking.

Although the MOPA machine is used for alumina blackening, the laser blackening process has relatively high requirements in all aspects, otherwise it will cause uneven marking, insufficient blackness, slow speed, insufficient marking content accuracy, etc. . Fulan Laser aims to let customers better understand the principle and process requirements of alumina blackening. In order to improve the quality of blackening products and the efficiency of marking processing, we have specially compiled a list of the principles of alumina blackening and the factors affecting alumina blackening for your reference.

The principle of alumina blackening: the laser emitted by the laser undergoes a series of treatments, and the high-energy density laser is focused by the lens to further oxidize the alumina layer and change the color of the surface material in a short time. This is the nano effect, because the oxide particle size is nanometer level after laser processing, so the light absorption performance of the substance is increased, so that visible light is irradiated on the substance and absorbed, and the reflected visible light is very small, so the naked eye is black.

Main factors affecting alumina laser blackening

1. Material

Substrate material: the purity of aluminum material, that is, the contained elements and their content, will affect the effect after oxidation, and the effect after oxidation will affect the blackening effect;

Oxide film thickness: 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 black. When the film thickness is less than 8um, the oxide film is too thin, easy to break, and white spots appear, and the pulse needs to be increased. Frequency and increase packing density

Surface treatment process: The 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. .

2. Marking process

Focusing lens focal length: The selection of field lenses with different focal lengths depends on the spot size and working range after focusing. Aluminum is blackened. Fulan Laser recommends that you choose a 160mm field lens. If you choose a larger field lens, you need to increase the laser power or reduce it. Marking speed;

Filling density and galvanometer speed: During the blackening process, the filling density and the galvanometer speed have a certain connection relationship. Generally, the filling density is denser, and the linear speed of the galvanometer can be higher. On the contrary, the filling density is sparse and the line of the galvanometer The speed must be lowered to achieve the same marking blackness;

Positive focus or defocus: Foshan Fulan Laser recommends that customers use positive focus, because defocus is prone to unevenness when the marking area is large or the consistency of the material being marked is not high;

Filling method: The filling method directly determines the quality and efficiency of blackening. Under normal circumstances, the selection of serpentine filling can greatly improve the blackening efficiency, and the one-way filling can improve the quality of blackening. Other filling methods also have their own characteristics. Customers can choose the most suitable method after proofing according to different requirements.

3. Laser marking machine parameter setting: The parameter setting will directly affect the quality and effect of aluminum blackening. The main laser parameters are power setting and frequency setting. The higher the frequency, the shorter the pulse width, and the higher the power required. , Due to the difference in materials and film thickness, customers must adjust the parameters according to the specific conditions during testing to achieve the best results.

4. Equipment configuration: The mopa laser marking machine for aluminum black produced by Foshan Fulan Laser Technology Co., Ltd. has three specifications: FL-MP2Q, FL-MP3Q and FL-MP6Q, which are mainly different from the laser power. The laser power is 20W, 30W, 60W. To produce the best black color, it depends on the purity of the substrate material, the thickness of the oxide film, and the surface treatment process. Some use 20W to achieve the best results, and some It takes 30W or 60W to get the best results.

In addition to the 4 points mentioned above, the experience of equipment operators, equipment interference, and environmental interference will directly affect the blackening effect of alumina.

No matter what material you are using for marking, and what effect you want to achieve, Fulan Laser recommends that you try to make a sample before purchasing, first to see if the marking effect meets your requirements. You can visit Fulan Laser for on-site inspection and proofing free of charge, or you can mail samples to Fulan Laser, and Fulan Laser will make free samples for you.