In general, the use of auxiliary gas is necessary for material cutting, and involves the type and pressure of the auxiliary gas. In general, the auxiliary gas is injected coaxially with the laser beam to protect the lens from contamination and to blow away the slag at the bottom of the cutting zone. For non-metallic materials and metal materials, compressed air or inert gas is used to remove, melt and evaporate the material, while inhibiting excessive combustion in the cutting zone.
For most metals, laser cutting uses active gas (as long as O2) to form exothermic reactions with hot metals. This part of the additional heat can increase the cutting speed by 1/3 to 1/2.
The size of the gas pressure is an important factor to ensure the auxiliary gas. In high speed cutting of thin materials, higher gas pressure is needed to prevent the slag from sticking to the back of the cutting (heat, slag, damage to the workpiece and cutting edges). When the material thickness increases or the cutting speed is slow, should reduce the gas pressure suitably, in order to prevent the plastic edge frost formation, simultaneously also should reduce the gas pressure cutting.
The practice of laser cutting shows that the purity of auxiliary gas has obvious influence on the cutting quality of auxiliary gas. The purity of oxygen decreased by 2%, the cutting speed decreased by 50%, and the quality of cut decreased remarkably.