Metal laser cutting: different lasers for guaranteed millimeter precision

Minifaber, thanks to its state-of-the-art machinery and the experience accumulated over years of activity, is specialized in laser cutting metals of all kinds: iron, steel, aluminum and copper. For each of these, laser cutting, thanks to its properties, guarantees extremely clean and precise cuts.

Laser cutting consists of a thermal metal separation process: the laser beam, focusing on a specific point of the sheet thanks to the aid of a lens, heats up and quickly brings it to melting point.

At the same time, a gas (which can be inert or active) flowing from a nozzle located downstream of the focusing lens produces a fluid dynamic thrust sufficiently intense to remove the molten metal, thus generating the cutting groove. Processing proceeds by moving the laser beam along the desired cutting path.

Different types of laser cutting of metals depending on the gas used

Metal laser cutting can be carried out using two different techniques depending on the gas used in the processing phase:

• Melting: in this case, the gas used is inert, that is, it does not react once in contact with the cut metal; the most popular inert gases are nitrogen, argon and helium.
• Combustion: in this case the gas used is oxygen and is considered active as it reacts in contact with metal, generating metal oxide; this reaction releases an amount of energy additional to that of the laser beam which helps to melt the metal faster. Compared to the previous type, the advantage here lies in a greater laser power and the possibility of working on thicker surfaces and at greater speed.

Different types of laser cutting of metals depending on the source

Two different types of metal laser cutting are recognized depending on the type of laser beam source:

1. CO₂ laser cutting: these are gas lasers based on a gas mixture of electrically excited carbon dioxide and typically have a wavelength of 10 μm; one of the strengths of CO2 lasers is the excellent cutting quality even on thick sheet metal.
2. Fiber laser cutting: here the laser beam is produced by means of a so-called laser seed and is amplified by means of glass fibers, to which energy is fed by pumping diodes; the wavelength of fiber lasers is 1 μm. Fiber laser cutting, compared to the CO₂ laser, also allows non-conductive metals such as brass and copper to be cut, guarantees greater speed and requires less maintenance.

The Minifaber metal laser cutting process

To best perform the laser metal cutting process, Minifaber mainly uses a cutting-edge and always up-to-date machinery: in particular, 4 combined punching machines, capable of cutting sheet metal up to 1250x2500 mm, and a deburring machine, useful to eliminate any molten metal remnants (called "burrs").