During the fiber optic laser cutting process, the auxiliary gas works primarily as the driving force to remove metallic fluid from the sheet. Each gas has a different influence on the material to cut.

The use of auxiliary gas in metal cutting has the following benefits:

Blow excesses into the coaxial cut;
It cools the surface of the processed metals and reduces the area affected by heat;
Cools the focusing lens, preventing dust from entering the lens mount and contaminating or overheating;
Some cutting gases also help protect the base metal.
Assist gases include oxygen, nitrogen, air and, in rare cases, argon, and selecte base on the type of material cut, its thickness and the desire edge quality

Which gas is better?

Oxygen

When O2 adopte as an auxiliary gas, it not only expels the molten metal liquid, but also generates an oxidation reaction that promotes endothermic metal fusion, to achieve the fusion of thicker metals. This process significantly improves the processing capacity of the laser.

However, due to the presence of oxygen, the cutting surface of the material is obviously rusty. In addition, it has cooling effects generated on the material around the cutting surface.

Nitrogen

When N2 use as an auxiliary gas, it forms a protective atmosphere around the molten metal liquid, preventing the material from rusting, to ensure the quality of the cutting surface.

However, N2 does not have an oxidation effect to improve heat transfer, so it does not help improve cutting capacity. Besides being one of the most expensive.

Air

The air consists of 78% nitrogen and 21% oxygen. When air use as an auxiliary gas, oxidation of the cutting section is inevitable due to the presence of oxygen.

However, due to the presence of a large amount of nitrogen, the oxidation reaction caused by oxygen is not sufficient to improve heat transfer, and the cutting capacity does not improve. The advantage is that the cost of the air cut is very low.

Before choosing any auxiliary gas, it is necessary to take into account factors such as the cost of indirect labor, the desired edge quality, the cost of gas, the type of material to work and the power of the laser, so you can make a choice that benefit your pocket and that of your company.