Introduction to the Principles and Classification of Metal Laser Cutting Machines

Introduction to the Principle and Classification of Metal Cutting Machines

1、 Principle

A laser cutting machine uses a focused high-power density laser beam to irradiate a workpiece, causing the irradiated material to quickly melt, vaporize, ablate, or reach the ignition point. At the same time, it uses a high-speed airflow coaxial with the beam to blow away the molten material, thereby achieving the cutting of the workpiece. Laser cutting is one of the thermal cutting methods.

2、 Classification

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

1) 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 very short time. The material begins to vaporize, forming vapor. The ejection speed of these vapors is very high, and at the same time, they form notches on the material. The heat of vaporization of materials is generally very high, so laser vaporization cutting requires a high power and power density.

Laser vaporization cutting is commonly used for cutting extremely thin metal materials and non-metallic materials (such as paper, cloth, wood, plastic, rubber, etc.).

2) Laser melting cutting

When laser melting and cutting, the metal material is melted by laser heating, and then non oxidizing gases (Ar, He, N, etc.) are sprayed through a nozzle coaxial with the beam of light, relying on the strong pressure of the gas to discharge the liquid metal, forming a cut. Laser melting cutting does not require complete vaporization of the metal, and only requires 1/10 of the energy required for vaporization cutting.

Laser melting cutting is mainly used for cutting materials or active metals that are not easily oxidized, such as stainless steel, titanium, aluminum, and their alloys.

3) Laser oxygen cutting

The principle of laser oxygen cutting is similar to that of oxygen acetylene cutting. It uses laser as a preheating heat source and active gases such as oxygen as cutting gases. The sprayed gas, on the one hand, reacts with the cutting metal and undergoes an oxidation reaction, 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. Due to the oxidation reaction generated during the cutting process, a large amount of heat is generated, so the energy required for laser oxygen cutting is only half of that for melting cutting, and the cutting speed is much faster than 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.

4) Laser Scoring and Controlled Fracture

Laser slicing is the use of high-energy density laser to scan the surface of brittle materials, causing the material to evaporate into a small groove under heat, and then applying a certain pressure, the brittle material will crack along the small groove. The lasers used for laser slicing are generally Q-switched lasers and CO2 lasers.

Controlling fracture is the use of the steep temperature distribution generated during laser engraving to generate local thermal stress in brittle materials, causing the material to fracture along small grooves.

The above is an introduction to the principle of metal laser cutting machine. Metal laser cutting machine is a type of machine equipment that can automatically typeset. It can save a lot of materials, and the materials cut by the metal laser cutting machine are very flat, with very smooth cuts. Metal laser cutting machines can reduce processing costs during operations. Most processing manufacturers choose this type of equipment, which can effectively reduce the manufacturing and processing costs of enterprises.