Laser cutting is a horizontal laser beam emitted by a laser through a 45° total reflection mirror into a vertically downward laser beam, which is then focused by a lens to form a small spot at the focus. When the spot is illuminated on the material, The material is quickly heated to the vaporization temperature, evaporating to form a hole, and as the beam moves against the material, and the auxiliary gas (carbon dioxide gas, oxygen, nitrogen, etc.) is blown away to melt the molten residue, so that the hole is continuously formed into a narrow width ( For example, about 0.1 mm, the slit is cut to complete the cutting of the material.
Laser cutting uses a focused high-power-density laser beam to illuminate a workpiece, causing the material to be irradiated to rapidly melt, vaporize, ablate, or reach a flash point. At the same time, the molten material is blown off by a high-speed airflow coaxial with the beam, thereby cutting the workpiece. open. Laser cutting is one of the hot cutting methods. The principle of laser cutting is shown in the figure below.
The workpiece is heated using a high energy density laser beam. Vaporizes in a short period of time to form a vapor. A cut is formed in the material. The vaporization heat of the laser pointer material is generally large, so large power and power density are required for laser vaporization cutting.
Laser vaporization cutting is often used for cutting very thin metal and non-metallic materials such as paper, cloth, wood, plastics and rubber.
When laser melting and cutting, the metal material is melted by laser heating, and the nozzle sprays non-oxidizing gas (Ar, He, N, etc.), and the liquid metal is discharged by the strong pressure of the gas to form a slit. The required energy is only 1/10 of the vaporization cut.
Laser melt cutting is mainly used for the cutting of some non-oxidizable materials or active metals, such as stainless steel, titanium, aluminum and their alloys.
It uses a laser pointer as a preheating heat source, and uses an active gas such as oxygen as a cutting gas. The gas ejected on the one hand reacts with the cutting metal to cause an oxidation reaction to release a large amount of heat of oxidation; on the other hand, the molten oxide and the melt are blown out from the reaction zone, and the cutting speed is much greater than the laser vaporization cutting and the melt cutting.
Laser oxygen cutting is mainly used for easily oxidized metal materials such as carbon steel, titanium steel and heat-treated steel.
Laser dicing is to scan the surface of the brittle material with a high energy density laser, so that the material is evaporated to a small groove by heat, and then a certain pressure is applied, and the brittle material is cracked along the small groove. Lasers for laser scribing are generally Q-switched lasers and CO2 lasers.
Controlling the fracture is a steep temperature distribution created by the use of a laser pointer to create a local thermal stress in the brittle material that causes the material to break along the small groove.
Most laser cutting machines are controlled by CNC programs or made into cutting robots. As a sophisticated machining method, laser cutting can cut almost all materials, including 2D or 3D cutting of thin metal sheets.
In the field of automobile manufacturing, the cutting technology of space curves such as car roof windows has been widely used. Volkswagen AG uses a 500W laser to cut complex body sheets and various curved parts. In the aerospace industry, aerospace components processed by laser cutting include engine flame tube, titanium alloy thin wall machine, aircraft frame, titanium alloy skin, wing long stern, tail siding, helicopter main rotor, space shuttle ceramics. Heat insulation tiles, etc.
Laser cutting forming technology also has a wide range of applications in the field of non-metallic materials. Such as silicon nitride, ceramics, quartz, etc.; flexible materials, such as cloth, paper, plastic sheets, rubber, etc.