Laser cutting is a thermal cutting method that uses a focused high-power-density laser beam to irradiate the workpiece. This causes the irradiated material to rapidly melt, vaporize, ablate, or reach its ignition point. Meanwhile, high-speed airflow coaxial with the laser beam blows away the molten material, thereby cutting through the workpiece.
Classification and Characteristics of Laser Cutting
Laser cutting can be divided into four types: laser vaporization cutting, laser fusion cutting, laser oxygen cutting, and laser scribing and controlled fracture.
It uses a high-energy-density laser beam to heat the workpiece, rapidly raising its temperature to the material’s boiling point in an extremely short time, causing the material to vaporize and form vapor. The vapor is ejected at a high velocity, creating a cut in the material as it escapes. Since most materials have high vaporization heat, laser vaporization cutting requires substantial power and power density.
In laser fusion cutting, the laser heats and melts the metal material. A non-oxidizing gas (such as Ar, He, N, etc.) is then blown through a nozzle coaxial with the laser beam. The high pressure of the gas expels the molten metal, forming a cut. Unlike vaporization cutting, this method does not require complete material vaporization and only consumes 1/10 of the energy needed for vaporization cutting. It is mainly used for cutting non-oxidizable or reactive metals, including stainless steel, titanium, aluminum, and their alloys.
Laser Oxygen Cutting
The principle of laser oxygen cutting is similar to oxyacetylene cutting. The laser acts as a preheating heat source, while active gases (such as oxygen) serve as the cutting gas. On one hand, the blown gas reacts with the metal being cut, triggering an oxidation reaction that releases a large amount of oxidation heat. On the other hand, it blows away molten oxides and melts from the reaction zone, forming a cut in the metal. The oxidation reaction during cutting generates significant heat, so laser oxygen cutting only requires half the energy of fusion cutting, while its cutting speed is much faster than that of vaporization and fusion cutting. It is primarily applied to oxidizable metal materials like carbon steel, titanium steel, and heat-treated steel.
Laser Scribing and Controlled Fracture
Laser scribing uses a high-energy-density laser to scan the surface of brittle materials, evaporating a small groove. Applying a certain amount of pressure then causes the brittle material to fracture along the groove. Q-switched lasers and CO₂ lasers are commonly used for laser scribing. Controlled fracture leverages the steep temperature distribution generated during laser grooving to create local thermal stress in brittle materials, causing them to break along the scribed groove.
Applications of Laser Cutting
Most laser cutting machines are operated via numerical control (NC) programs or configured as cutting robots. As a precision processing method, laser cutting can cut almost all materials, including 2D or 3D cutting of thin metal sheets. In the aerospace field, laser cutting technology is mainly used for cutting special aerospace materials such as titanium alloys, aluminum alloys, nickel alloys, chromium alloys, stainless steel, beryllium oxide, composite materials, plastics, ceramics, and quartz. Aerospace components processed by laser cutting include engine flame tubes, thin-walled titanium alloy casings, aircraft frames, titanium alloy skins, wing stringers, tail wing panels, helicopter main rotors, and space shuttle ceramic heat-insulating tiles.
Post time: Dec-08-2025
