1. On the question of whether the nozzle is single-layer or double-layer, the single-layer laser nozzle is used for melting and cutting, that is, nitrogen is used as auxiliary gas, and the single-layer laser nozzle is used for cutting stainless steel and aluminum plates. Double layer laser nozzle is generally used for oxidation cutting, that is, oxygen is used as auxiliary gas, and double-layer laser nozzle is used for cutting carbon steel. In addition, for thin plates less than 3mm, the hole diameter of the selected nozzle should be Φ 1mm, so the cutting gap will be thinner. If it is larger, it will be thicker, and the position of the cutting corner will not be smooth. Cutting and selection of thick plates above 3mm and below 10mm Φ The nozzle aperture of 1mm will be unstable. If the power is higher, the cutting time will be longer due to the required heat dissipation time. If the aperture is too small, although the heat dissipation is fast, it is still unstable. Choose at this time Φ 1.5mm, and when the heat dissipation area is relatively large, the air flow will become slower, so it is easier to cut
stable.
2. From which aspects does the nozzle quality look
First: look at the material. A good nozzle must have high conductivity and good thermal conductivity. Generally, the nozzle made of red copper is better than that made of brass, which can ensure a good capacitive signal.
Second: look at the machining accuracy: for a good laser head nozzle, its concentricity should reach 0.03mm, while for a nozzle with a size of less than 1.0mm, its concentricity should reach 0.02mm. The nozzle with high-precision concentricity can not only reduce the early debugging in the processing process, but also effectively avoid the high-energy laser hitting the inner wall of the laser head, so as to avoid damage to the laser head. When the center of the nozzle is different from the center of the laser, the impact on the cutting quality: 1) affect the cutting section. When the cutting gas is ejected, it causes uneven air volume, making the cutting section more prone to the phenomenon of melting stains on one side and no melting stains on the other side. It has less impact on the cutting of thin plates less than 3mm. When cutting plates more than 3mm, its impact is more serious, and sometimes it will cause failure to cut. 2) It affects the quality of sharp corners. When cutting workpieces with sharp corners or small angles, it is easy to produce local over melting. When cutting thick plates, it may not be able to cut. 3) It affects the perforation. It is unstable during the 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, which has little impact on the perforation of thin plates.
Third: look at the surface finish and anti-oxidation treatment: a smooth surface and good anti-oxidation treatment can effectively reduce the attachment of molten matter in the cutting process and prolong the service life of the nozzle.