How to choose auxiliary gas for Fiber Laser Cutting Machine?

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How to choose auxiliary gas for Fiber Laser Cutting Machine?

Fiber Laser Cutting Machine needs to be equipped with auxiliary gases during use, mainly oxygen, nitrogen and air. When the fiber laser cutting machine is processing the workpiece, it will be irradiated by the laser focal spot, and the irradiated area will be instantly melted and vaporized, and then the spot irradiation position is moved through the numerical control equipment system to realize automatic cutting.

1. Compressed air.

Air is suitable for cutting aluminum plates and galvanized steel plates. To a certain extent, it can reduce oxide film and save costs. Generally, it is used when the cutting board is relatively not thick and the cutting end face is not too high.

2, nitrogen.

Nitrogen is an inert gas, which prevents oxidation of the cut end surface of the product during cutting, and prevents combustion (prone to occur when the sheet is thick. Nitrogen can be selected for products that require high cutting end surfaces and are exposed without processing.

3. Oxygen.

Oxygen mainly plays a role in supporting combustion, which can increase the speed during cutting and increase the cutting thickness. Oxygen is suitable for thick plate cutting, high-speed cutting and thin plate cutting. For example, some larger carbon steel plates and some thicker carbon steel structures can use oxygen.

Increasing the gas pressure can increase the cutting speed, but after reaching a set value, continuing to increase the gas pressure will cause the cutting speed to drop. Under high auxiliary gas pressure, the reason for the decrease in cutting speed can be attributed to the high air velocity and the enhancement of the cooling effect of the active area, and the intermittent shock wave in the air current may interfere with the cooling of the laser active area.

The uneven pressure and temperature in the airflow will cause the change of the airflow field density. Such a density gradient results in a change in the refractive index in the field, thereby constricting the focus of the beam energy, causing refocusing or beam divergence. This interference will affect the melting efficiency, and sometimes may change the mode structure, resulting in a decrease in cutting quality if the beam diverges too much. To make the light spot too large may even cause serious consequences that cannot be effectively cut.

Application of auxiliary gas:

1. Compressed air: It is widely used in the processing of some sheet metal chassis, cabinets, cabinets and other products.

2, Nitrogen: processing some parts in the decoration industry, aerospace, etc.;
Fiber Laser Cutting Machine uses different auxiliary gases to cut different materials. The pressure and required flow rate of the auxiliary gas vary with the thickness of the cutting material.