During the laser cutting process, an auxiliary gas suitable for the material to be cut must be added. In addition to blowing away the slag in the slit, the coaxial gas can also cool the surface of the processed object, reduce the heat-affected zone, cool the focusing lens, and prevent smoke and dust from entering the lens seat to contaminate the lens and cause the lens to overheat. Therefore, the choice of the type of auxiliary gas will have a certain impact on the cutting performance, including cutting speed, cutting thickness, etc.
The characteristics and uses of different auxiliary gases for mixed laser cutting machine are as follows:
(1) O2
Mainly used for laser cutting machine cutting carbon steel. The heat of O2 reaction can not only greatly improve the cutting efficiency, but also the oxide film produced can also improve the beam spectral absorption factor of the reflective material. The end face of the incision is black or dark yellow. It is mainly suitable for rolled steel, rolled steel for welding structure, carbon steel for mechanical structure, high tension plate, tool plate, stainless steel, electroplated steel plate, copper and copper alloy, etc.
(2) N2
When some metals are cut with O2, an oxide film will be formed on the cutting surface, but the use of N2 can avoid the appearance of the oxide film and perform oxidation-free cutting. The non-oxidized cutting surface has the characteristics of direct welding and coating, and strong corrosion resistance. The end face of the incision is whitish. The main applicable plates are stainless steel, electroplated steel plate, brass, aluminum and aluminum alloy, etc.
(3) Air
Since air can be supplied directly by an air compressor, it is very cheap compared to other gases. Although the air contains about 20% O2, the cutting efficiency is far less than that of O2, and the cutting ability is similar to that of N2. A small amount of oxide film will appear on the cut surface, but it can be used as a measure to prevent the coating layer from falling off. The end face of the incision is yellow. The main applicable materials are aluminum, aluminum alloy, stainless steel, brass, electroplated steel and non-metal, etc.
(4) Ar
Ar is an inert gas, which is used to prevent oxidation and nitriding in laser cutting machine cutting, and can also be used in welding. Compared with other processing gases, the price is higher, which will increase the cost accordingly. The end face of the incision is whitish. The main applicable materials are titanium and titanium alloys.
