A laser cutting machine emits laser light into a high-power laser beam through an optical path system. The laser beam irradiates the surface of the workpiece, causing it to reach the melting or boiling point, and high-pressure gas coaxial with the beam blows away the melted or vaporized metal. As the beam of light moves relative to the workpiece, the material forms a joint, thereby achieving the purpose of cutting.

The mechanical part of the laser cutting machine blade does not come into contact with the workpiece, and does not scratch the surface of the workpiece during operation; Laser cutting speed is fast, the incision is smooth and smooth, and generally does not require subsequent processing; Small cutting heat affected area, small plate deformation, and cutting seams; The incision is free of mechanical stress and shear burrs; High machining accuracy, good repeatability, and no damage to the material surface. So, what is the principle of a metal laser cutting machine? What is the main cutting process of a laser cutting machine?

Laser cutting processing

Principle and cutting process analysis of metal laser cutting machine:

1. Principle of laser cutting machine

The laser cutting machine uses a focused high-power density laser beam to irradiate the workpiece, causing the irradiated material to quickly melt, vaporize, corrode, or reach the ignition point. The molten material is blown away by a high-speed airflow coaxial with the beam, thereby cutting the workpiece. The process parameters (cutting speed, laser power, air pressure, etc.) and motion trajectory during the cutting process are controlled by the CNC system, and the slag at the cutting joint is blown away by a certain pressure of auxiliary gas. Laser cutting is one of the thermal cutting methods.

2. Laser cutting machine cutting process

Laser cutting can be divided into four cutting processes: laser vaporization cutting, laser melting cutting, laser oxygen cutting, laser slicing, and controlled fracture.

Laser vaporization cutting: Using a high-energy density laser beam to heat the workpiece, the temperature rises rapidly and reaches the boiling point of the material in a short time. The material begins to evaporate, forming steam. The spraying speed of steam is very fast. The heat is high, and when the steam is sprayed, a notch is formed on the material. Laser vaporization cutting is mainly used for cutting extremely thin metal and non-metallic materials (such as paper), cloth, wood, plastic, rubber, etc.

Laser melting cutting: Metal materials are heated and melted by laser, and then non oxidizing gases (Ar. He. N et al.) are sprayed through a nozzle coaxial with the beam of light. The liquid metal is discharged by the strong pressure of the gas, forming a cut. The energy required for laser melting cutting is only 1/10 of that for vaporization cutting. Laser melting cutting is mainly used to cut materials or active metals that are not easily oxidized, such as stainless steel, titanium, aluminum, and their alloys.

Laser oxygen cutting: Using laser as a preheating heat source and active gases such as oxygen as cutting gas. On the one hand, the sprayed gas undergoes an oxidation reaction with the cutting metal, releasing a large amount of oxidation heat; On the other hand, molten oxides and molten materials are blown out of the reaction zone, forming notches in the metal. The energy required for laser oxygen cutting is only half of that for melting cutting, and the cutting speed is much faster than that of laser vaporization cutting and melting cutting. Laser oxygen cutting is mainly used for easily oxidizable metal materials such as carbon steel, titanium steel, and heat treated steel.

Laser slicing and controlled fracture: Using high-energy density laser to scan the surface of brittle materials, heating the material to evaporate small grooves, resulting in large thermal gradients and severe mechanical deformation in the area. Then, applying a certain pressure causes brittle materials to crack along the small grooves. As long as the heating gradient is maintained in balance, the laser beam can guide the generation of cracks in any desired direction.