What gases are there in the welding head of a laser welding machine?

helium, argon, and nitrogen in the welding head of welding machine.

1, Helium not easily ionized (higher ionization energy), which allows the laser to pass smoothly. And the beam energy to reach the surface of the workpiece unhindered. This is the most effective shielding gas used in laser welding. But it is more expensive.

2, argon is cheaper and has a higher density, so the protection effect is better. However, it is susceptible to high-temperature metal plasma ionization. As a result, it shields part of the light beam from being radiated to the workpiece, reduces the effective laser power for welding. And damages the welding speed and penetration. Weldments protected with argon are smoother than those protected with helium.

3. Nitrogen is the cheapest protective gas, but it is not applicable to some types of stainless steel welding, mainly due to metallurgy problems, such as absorption, sometimes generating pores in the overlap area.

1. Protect the focusing lens from metal vapor contamination and liquid droplet splashing.

Protective gas can protect the focusing lens of laser welding machine from metal vapor contamination and sputtering of liquid droplets. Especially in high-power welding, because its ejection becomes very powerful, it is more necessary to protect the lens at this time.

2, shielding gas is effective for dissipating the plasma shield generated by high power laser welding.

The electron recombination rate is increased by increasing the collision of electrons with ions and neutral atoms, so as to reduce the electron density in the plasma. The lighter the neutral atom, the higher the collision frequency and the higher the recombination rate. On the other hand, only a protective gas with high ionization energy will not increase the electron density due to the ionization of the gas itself.