Understand the development of laser cutting processing industry related knowledge

Laser cutting is a widely used technology in laser processing. Pulsed laser is suitable for metal materials, continuous laser is suitable for non-metallic materials, is an important application field of laser cutting processing technology. The laser beam combined with computer-controlled automatic equipment has unlimited copying cutting capability, and the cutting trajectory is easy to modify. Laser cutting processing without mechanical deformation, no tool wear, easy to achieve automatic production.

Laser cutting processing is widely used in sheet metal processing, hardware processing, advertising, kitchenware, automobiles, lamps, saw blades, elevators, metal crafts, textile machinery, grain machinery, eyewear production, aerospace, medical equipment, instrumentation and other industries. In particular, the sheet metal processing industry has replaced the traditional processing methods and is favored by industry users.

1. Laser cutting processing technology.

Laser cutting processing is the use of high power density laser beam irradiation cutting materials, so that the material quickly heated to the evaporation temperature, evaporation to form holes. With the movement of the light beam on the material, the hole continuously forms a narrow (about 0.1mm) gap, completing the cutting of the material.

Laser cutting processing can be divided into laser vaporization cutting, laser melting cutting, laser oxygen cutting, laser cutting processing and controlled cutting.

1. Laser vaporization cutting.

Using a high-energy density laser beam to heat the workpiece, the temperature rises rapidly, reaching the boiling point of the material in a very short time. Steam is sprayed at high speed, creating a notch in the material. The heat of vaporization of materials is generally large, so laser vaporization cutting requires a lot of power and power density.

Laser evaporation is used to cut thin metallic and non-metallic materials (such as paper, cloth, wood, plastic, rubber, foam, etc.). Ultrashort pulsed lasers allow the technology to be applied to other materials. The free electrons in the metal absorb the laser light and heat it violently. The laser pulse does not react with the molten particles and plasma, the material sublimates directly, and there is no time to transfer energy in the form of heat to the surrounding material. There is no obvious thermal effect during picosecond pulse ablation. Melting and burr formation.

2. Laser melting cutting.

In laser fusion cutting, the molten metal material is heated by the laser and then injected with a non-oxidizing gas through a nozzle coaxial with the beam (AR.he.N et al.). The liquid metal is discharged by the strong pressure of the gas, forming a incision. Laser melting cutting does not require complete evaporation of the metal and requires only 1/10 of the energy required for evaporation cutting.

Laser fusing is mainly used to cut non-oxidizing materials or active metals such as stainless steel, titanium, aluminum and its alloys, and can also be used to cut other fusible materials such as ceramics.

3. Laser oxygen cutting (flame cutting)

The principle of laser oxygen cutting is similar to that of oxyacetylene cutting. It uses a laser as a preheating heat source, and oxygen and other active gases as cutting gases. On the one hand, the gas injection reacts with the cutting metal and releases a lot of oxidation heat; On the other hand, it blows the molten oxide out of the reaction zone, creating a notch in the metal. Due to the large amount of heat generated by the oxidation reaction during the cutting process, the energy required for laser oxygen cutting is only half of that for melting cutting, and the cutting speed is much higher than that for laser vaporization cutting and melting cutting. Laser oxygen cutting is mainly used for carbon steel, titanium steel, heat treated steel and other easily oxidized metal materials.

4. Laser marking and fracture control.

Laser engraving uses a high energy density laser to scan the surface of the brittle material, so that the material is heated and evaporated into a small slot, and then a certain pressure is applied, and the brittle material cracks along the small slot. Laser engraving lasers are generally Q-switched lasers and CO2 lasers.

Controlled fracture uses the steep temperature distribution generated by laser grooving to generate local thermal stress in the brittle material, causing the material to fracture along the small grooves.