Laser cutting is a thermal cutting process. With the help of a laser beam, the material, which is blown away downwards immediately after its formation with a gas stream, melts or vaporizes. It is a highly precise process often recommended in applications requiring tight tolerances, precise cutouts, or holes that are small in relation to the material thickness.
A continuous cut is produced by moving the laser beam or workpiece under CNC control. The vast majority of laser cutting systems are two-axis machines that move in the X and Y direction, and as such are primarily designed for cutting 2D shapes. Each axis is driven with the use of stepper motors, and these are themselves controlled by a computer.
While Laser cutting typically used for industrial manufacturing applications, it is now used by schools, small businesses, architecture, and hobbyists.
Three Main Types of Lasers for Cutting
The CO2 lasers belong to the group of gas lasers and are also called carbon dioxide lasers. The cutting is done using electrically-stimulated CO2. The CO2 laser is produced in a mixture that consists of other gases like nitrogen and helium.
CO2 lasers score with a very good cutting quality and are mainly used for metallic materials but also for non-metallic materials like wood, textiles, plastics, foils, acrylic, glass, paper and leather. In contrast to fiber lasers, carbon dioxide lasers can also be used to process even thicker stainless steel sheets with good cutting quality.
The disadvantage is the comparatively high operating and maintenance costs for the laser gases as well as for consumables working in the laser source.
The fiber laser, which is a special form of solid-state laser, is on the advance. Here, cutting is done using fiberglass. The “seed laser” produces the laser beam and is then amplified within a glass fiber. Thanks to a beam wavelength that is ten times shorter than that of the CO2 laser, the fiber laser is also suitable for cutting materials that are otherwise difficult or impossible for the CO2 laser to cut, especially non-ferrous metals (NF metals).
It scores with its cost-effectiveness, low operating costs and long service life of the wear parts. The laser sources are also highly effective and consume significantly less input current for the same power.
Neodymium-doped Yttrium Aluminum Garnet (Nd: YAG) laser is a solid state laser in which Nd: YAG is used as a laser medium. Metals, metals with coatings and plastics are processed with this solid-state laser. In contrast to fiber lasers, however, this cutting technology has a high wearing of pump diodes. In addition, the lifetime of the neodymium-doped YAG crystal is shorter than that of the fiber laser.