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Types and functions of shielding gas for laser welding machine
Jul 13, 2021The 1000W handheld laser welding machine often uses inert gas to protect the molten pool during use. When the material to be welded does not have surface oxidation, the shielding gas may not be considered. But in most cases, shielding gas is still needed. Today, the editor will introduce the types and functions of shielding gas for laser welding machine.
The commonly used types of shielding gas for 1500W laser welding machines are:
1.Helium
It is not easy to ionize (high ionization energy), which allows the laser to pass smoothly, and the beam energy reaches the surface of the workpiece without hindrance. This is the most effective shielding gas used in laser welding, but it is more expensive.
2. Argon
The price is cheaper, the density is higher, and the protection effect is better, but it is susceptible to high-temperature metal plasma ionization. As a result, part of the beam is shielded from the workpiece, which reduces the effective laser power for welding, and also damages the welding speed and penetration. The surface of the weldment protected by argon is smoother than when protected by helium.
3. Nitrogen
It is the cheapest as a shielding gas, but it is not suitable for welding some stainless steels. Mainly due to metallurgical problems, such as absorption, sometimes pores are generated in the overlap area.
The functions of shielding gas for hot sale laser welding machine include:
1. When welding, isolate oxygen and air to reduce oxidation reaction during metal welding, so that blackening can be effectively reduced during welding. When the laser welding machine uses shielding gas, the shielding gas must be set first, and then the laser is emitted, which can prevent the pulse laser from oxidizing during the continuous processing of the laser welding machine.
2. Protect the focusing lens from metal vapor pollution and liquid droplet sputtering, especially for high-power welding. Because the ejected material is very powerful, it is necessary to protect the lens.
3. The shielding gas can dissipate the plasma shield produced by high-power laser welding. The metal vapor absorbs the laser beam and ionizes into a plasma cloud. The protective gas surrounding the metal vapor will also be ionized by heating. The electron recombination rate is increased by increasing the collision of electrons with ions and neutral atoms to reduce the electron density in the plasma.