Main parameters of laser cutter
1. Cutting speed
Given the laser power density and material, the cutting speed conforms to an empirical formula. As long as the cutting speed is above the threshold, the cutting speed of the material is proportional to the laser power, that is, increasing the power density can increase the cutting speed. The cutting speed is also related to the density of the material to be cut. Thickness is inversely proportional to factors that increase cutting speed:
(1) Increase power (500-3000w);
(2) Change the beam mode;
(3) Reduce the size of the focused spot (such as using a short focal length lens)
For metal materials, other process variables remain unchanged, and the laser cutting speed can have a relative adjustment range and still maintain a satisfactory cutting quality. This adjustment range is relatively wide when cutting thin metals.
2. Focus position
After the laser beam is focused, the spot size is proportional to the focal length of the lens. After the beam is focused by a short focal length lens, the spot size is very small, and the power density at the focal point is high, which is very beneficial for material cutting, but its disadvantage is that the focal depth is very short. The adjustment margin is very small, and it is generally suitable for high-speed cutting of thin materials. For thick workpieces, because the telephoto long lens has a wider focal depth, as long as it has sufficient power density, it is more suitable for cutting it, because the power density at the focal point is the highest. , In most cases, when cutting, the focus position is just on the surface of the workpiece, or slightly below the surface of the workpiece, ensuring that the relative position of the focus and the workpiece is constant is an important condition to obtain stable cutting quality, and sometimes the lens is working due to poor cooling. The focal length changes due to heat, which requires timely adjustment of the focal position.
3. Auxiliary gas
The auxiliary gas is sprayed coaxially with the laser beam to protect the lens from contamination and blow away the slag at the bottom of the cutting area. For non-metallic and some metal materials, use compressed air or inert gas to remove the melted and evaporated material, while suppressing excessive cutting area. combustion.
4. Auxiliary gas pressure
Most metal laser cutting uses active gas (oxygen) to form an oxidative exothermic reaction with the hot metal. This part of the additional heat can increase the cutting speed by 1/3-1/2. When cutting thin plates at high speed, higher gas is required The pressure prevents slag on the back of the incision. When the material thickness or cutting speed is slow, the gas pressure can be appropriately reduced.
5. Laser output power
The size of the laser power and the quality of the mode will have an important impact on the cutting. In actual operation, the maximum power is often set to obtain a high cutting speed or to cut thick materials.