.Why lasers are used for cutting?
“LASER”, an acronym for Light Amplification by Stimulated Emission of Radiation, is widely used in all walks of life, when the laser is applied to the cutting machine, it achieves a cutting machine with high speed, low pollution, less consumables, and a small heat affected zone. At the same time, the photoelectric conversion rate of the laser cutting machine can be as high as twice that of the carbon dioxide cutting machine, and the light length of the fiber laser is 1070 nanometers, so it has a higher absorption rate, which is more advantageous when cutting thin metal plates. The advantages of laser cutting make it the leading technology for metal cutting, which is widely used in the machining and manufacturing industry, the most typical of which are sheet metal cutting, cutting in the automotive field, etc.
.How does a laser cutter work ?
I. Laser Processing Principle
The laser beam is focused into a light spot with a very small diameter (the minimum diameter can be less than 0.1mm). In the laser cutting head, such a high-energy beam will pass through a special lens or curved mirror, bounce in different directions, and finally gathered on the metal object to be cut. Where the laser cutting head has cut, the metal rapidly melts, vaporizes, ablates, or reaches an ignition point. The metal vaporizes to form holes, and then a high-velocity airflow is sprayed through a nozzle coaxial with the beam. With the strong pressure of this gas, the liquid metal is removed, forming slits.
Laser cutting machines use optics and computer numerical control (CNC) to guide the beam or material, usually this step uses a motion control system to track the CNC or G code of the pattern that to be cut onto the material, to achieve cutting different patterns .
II. Main methods of laser processing
1) Laser melt cutting
Laser melting cutting is to use the energy of the laser beam to heat and melt the metal material, and then spray compressed non-oxidizing gas (N2, Air, etc.) through the nozzle coaxial with the beam, and remove the liquid metal with the help of strong gas pressure to form a cutting seam.
Laser melt cutting is mainly used to cut non-oxidizing materials or reactive metals such as stainless steel, titanium, aluminum and their alloys.
2) Laser oxygen cutting
The principle of laser oxygen cutting is similar to oxyacetylene cutting. It uses the laser as the preheating source and the active gas such as oxygen as the cutting gas. On the one hand, the ejected gas reacts with the metal, generating a large amount of heat of oxidation.This heat is enough to melt the metal. On the other hand, molten oxides and molten metal are blown out of the reaction zone, creating cuts in the metal.
Laser oxygen cutting is mainly used for easily oxidized metal materials such as carbon steel. It can also be used for the processing of stainless steel and other materials, but the section is black and rough, and the cost is lower than that of inert gas cutting.
Post time: Aug-15-2022