The laser cutting machine uses various auxiliary gases to assist the cutting process when cutting. The cutting process used and the material to be cut determine the type of auxiliary gas (inert or active gas) most suitable for use. An inert gas cutting (ie, melting cutting or inert gas melt shearing) uses a chemically inert auxiliary gas.
The specific auxiliary gas used depends on the reactivity of the material.
Since molten thermoplastic does not react with nitrogen and oxygen, compressed air can be used as an auxiliary gas when laser cutting such materials.
Since molten titanium does react with nitrogen and oxygen, argon (or other chemically inert gas) must be used as an auxiliary gas in laser cutting applications involving this material. When laser cutting stainless steel through an inert gas cutting process, nitrogen is usually used as an auxiliary gas. This is because molten stainless steel reacts chemically with oxygen.
When laser cutting materials through a reactive melt shearing process, an active (ie, chemically reactive) auxiliary gas (usually oxygen) is used to accelerate the cutting process. In inert gas cutting, only the power of the laser is used to heat, melt and vaporize the material, while in reactive gas cutting, the reaction between the auxiliary gas and the material generates additional heat, which helps the cutting process. Due to this exothermic reaction, reactive gas cutting generally requires a lower laser power level to penetrate the material compared to the power level required when cutting the same material through an inert gas cutting process.
2.The cutting pressure of the auxiliary gas used also depends on the cutting process used and the characteristics and thickness of the material being cut.
For example, in an inert gas cutting process, polymers usually require a gas injection pressure of 2-6 bar, while stainless steel requires a gas injection pressure of 8-14 bar. Therefore, thinner materials generally require a lower pressure, and thicker materials generally require higher pressure. In oxidative cutting, the situation is just the opposite: the thicker the material, the lower the pressure required, and the thinner the material, the higher the pressure required.
