1) laser vaporization cutting
The workpiece is heated by a laser beam with high energy density, so that the temperature rises rapidly and reaches the boiling point of the material in a very short time, and the material begins to vaporize and form steam. These vapors are ejected at high speed, and at the same time, cuts are formed in the material. The vaporization heat of materials is generally very large, so laser vaporization cutting requires a lot of power and power density.
Laser vaporization cutting is mostly used to cut extremely thin metal materials and non-metal materials (such as paper, cloth, wood, plastic, rubber, etc.).
2) laser melting and cutting
In the process of laser melting and cutting, metal materials are melted by laser heating, and then non-oxidizing gases (Ar, he, N, etc. ) injected through a nozzle coaxial with the light beam, the liquid metal is discharged by the strong pressure of gas to form a cut. Laser melting cutting does not need to completely vaporize the metal, and the energy required is only110 of the vaporized cutting.
Laser melting cutting is mainly used to cut some materials or active metals that are not easy to be oxidized, such as stainless steel, titanium, aluminum and their alloys.
3) Laser oxygen cutting
The principle of laser oxygen cutting is similar to oxyacetylene cutting. It uses laser as preheating heat source and active gas such as oxygen as cutting gas. On the one hand, the blown gas reacts with the cut metal to produce oxidation reaction, releasing a lot of oxidation heat; On the other hand, molten oxide and melt are blown out of the reaction zone, forming a gap in the metal. Because the oxidation reaction in the cutting process generates a lot of heat, the energy required by laser oxygen cutting is only 1/2 of that of melting cutting, and the cutting speed is much higher than that of laser vaporization cutting and melting cutting. Laser oxygen cutting is mainly used for oxidizable metal materials such as carbon steel, titanium steel and heat-treated steel.
4) Laser cutting and fracture control.
Laser scribing is to scan the surface of brittle material with high energy density laser, so that the material evaporates into a small groove when heated, and then the brittle material will crack along the small groove when a certain pressure is applied. The lasers used for laser scribing are usually Q-switched lasers and CO2 lasers.
Controlled fracture is to use the steep temperature distribution produced by laser grooving to produce local thermal stress in brittle materials, which makes the materials fracture along small grooves.