Laser cutting works in continuous or repetitive pulse mode. During the cutting process, the laser beam is focused into a small spot (the smallest diameter can be less than 0.1mm), so that the focal point can reach a high power density (more than 10W/cm2).
At this time, the heat input by the light beam (converted by light energy) far exceeds the part reflected, conducted, or diffused by the material, and the material is quickly heated to the melting and vaporization temperature. At the same time, a high-speed airflow from the coaxial or non-coaxial direction blows the melted or vaporized material from the lower part of the material.
With the relative movement of the beam and the material, the hole forms a slit with a very narrow width (0.1~0.3mm) to separate the material. In addition to the lens, it also has a coaxial nozzle that ejects a stream of auxiliary gas.
The characteristics of laser cutting can be summarized as:
- The cutting quality is good, the cutting seam geometry is good, the two sides of the incision are nearly parallel and perpendicular to the bottom surface;
- Non-sticky slag, narrow cutting seam, small heat-affected zone, basically no workpiece deformation
- There are many types of materials that can be cut by laser. Gas cutting can only cut low-carbon steel, medium-carbon steel, and alloy steel with small Cr content, while a laser can cut metals, non-metals, metal-based and non-based composite materials, leather, and wood;
- High cutting efficiency;
- Non-contact processing;
- Low noise;
- Low pollution
Comparison of laser cutting and other cutting methods (6.2mm thick steel plate)
| Cutting method | Cutting width (m) | Heat affected zone width (mm) | Cut pattern | speed | equipment cost |
| Laser cutting | 0.2-0.3 | 0.04–0.06 | Parallel | Fast | high |
| Gas cutting | 0.9-1.2 | 0.6-1.2 | Relatively parallel | slow | low |
| Plasma cutting | 3.0-4.0 | 0.5~1.0 | Plasma cutting | Fast | Mid to high |
