The role of shielding gas on laser welding and cleaning machines

  Why use shielding gas for hand-held laser welding machine welding? The reasons can be divided into three points:

Reason 1: Protect the focusing lens from metal vapor contamination and droplet sputtering

  The shielding gas can protect the focusing lens of the laser welding machine from metal vapor contamination and droplet sputtering, especially during high-power welding, because the spray becomes very powerful, and the lens protection is more necessary at this time.

Reason 2: Shielding gas is very effective for dissipating plasma shielding produced by high-power laser welding

  The metal vapor absorbs the laser beam and is ionized into a plasma cloud, and the shielding gas surrounding the metal vapor is also ionized by heating. If there is too much plasma, the laser beam is consumed to some extent by the plasma. The plasma is present on the working surface as a second energy, resulting in a shallower penetration and a wider pool surface. The electron density in the plasma is reduced by increasing the electron recombination rate by increasing the triple collision of electrons with ions and neutral atoms. The lighter the neutral atom, the higher the collision frequency and the higher the recombination rate; on the other hand, only the shielding gas with high ionization energy does not increase the electron density due to the ionization of the gas itself.

Reason 3: The shielding gas can protect the workpiece from oxidation during the welding process

  The laser welding machine must have gas protection, and the program must be set to emit the shielding gas first, and then the laser to prevent oxidation of the pulsed laser during continuous processing. Inert gas can protect the molten pool. When welding some materials, surface oxidation is negligible. However, for most applications, helium, argon, nitrogen, and other gases are often used for shielding, which protects the workpiece from the welding process. oxidation. The above is the reason why shielding gas is used in laser welding machine welding. Remind you that helium is generally used as a protective gas, which can suppress the plasma to the greatest extent, thereby increasing the penetration depth and improving the welding speed; and it is light in weight, can escape, and is not easy to cause pores. Of course, from the effect of our actual welding, the effect of argon protection is not bad. Hanteng Laser specializes in the production of laser welding machines, and the boss in need can consult at any time.