How to choose the right laser nozzle for laser cutting

How to choose the right laser nozzle for laser cutting

1. Regarding the single-layer or double-layer of the nozzle, the single-layer laser nozzle is used for melting and cutting, that is, nitrogen is used as the auxiliary gas, and the single-layer laser nozzle is used for cutting stainless steel and aluminum plates. Double-layer laser nozzles are generally used for oxidation cutting, that is, using oxygen as auxiliary gas to cut carbon steel with double-layer laser nozzles.

Laser Nozzle - Laser Cutting

2. Questions about the selection of nozzle aperture

Nozzles with different aperture orifices are mainly used for cutting plates of different thicknesses. Thin plates use smaller orifices, and thick plates use larger orifices. The nozzle apertures are: 0.8, 1.0, 1.2, 1.5, 1.8, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, etc., and the most used ones are: 1.0, 1.2, 1.5, 2.0, 2.5, 3.0, and here The most commonly used ones are 1.0, 1.5, and 2.0. The aperture of the nozzle controls the flow of gas and the shape of the gas field, which is very important to the quality of the cut. Generally, when a laser cutting machine is used to cut a thin plate below 3mm, it is recommended to use a nozzle with a diameter of 1mm, and a nozzle with a diameter of 1.5mm is recommended for a thickness of more than 3mm. When cutting metal plates with a diameter of 10mm or more, a nozzle with a diameter of 2mm or more is generally selected.

3. The quality of the nozzle should be looked at from the aspects of the first: look at the material, a good nozzle, the material must have high conductivity and good thermal conductivity. Generally, the nozzle made of red copper is better than the one made of brass, which can ensure a good capacitive signal.

Second: look at the processing accuracy: a good laser head nozzle should have a concentricity of 0.03mm, and a nozzle with a size below 1.0mm should have a concentricity of 0.02mm. The high-precision concentric nozzle can not only reduce the early debugging in the processing process, but also effectively prevent the high-energy laser from hitting the inner wall of the laser head, thereby avoiding damage to the laser head. When the center of the nozzle is not coaxial with the center of the laser, the impact on the cutting quality: 1) It affects the cutting section. When the cutting gas is ejected, the gas volume is not uniform, so that the cutting section is more likely to have melting stains on one side and no melting on the other side. The phenomenon of cutting the thin plate below 3mm, its influence is small, when cutting the plate above 3mm, its influence is more serious, and sometimes it can not be cut. 2) It affects the quality of sharp corners. When cutting workpieces with sharp corners or small angles, local over-melting is easy to occur. When cutting thick plates, it may not be possible to cut. 3) Affects perforation. It is unstable during perforation, and the time is not easy to control. The penetration of thick plates will cause over-melting, and the penetration conditions are not easy to grasp, and the impact on the perforation of thin plates is small.

Third: Look at the surface finish and anti-oxidation treatment: smooth surface and good anti-oxidation treatment can effectively reduce the adhesion of molten material during the cutting process and prolong the service life of the nozzle.