A laser beam, scientifically speaking, is a stream of coherent electromagnetic radiation. This means that you can increase the energy density per unit of treated surface as much as you like, and it will not be uselessly dissipated in space.
To understand the advantages of this method of cutting metal, consider the competing methods of cutting metal — flame, milling, water jet.
When the gas burner is operating, the temperature of the working fluid does not exceed 2100 °C, as a result of which the steel, which has a melting point of about 1800 °C, melts rather slowly, the workpiece has time to overheat, followed by non-warping. There are also certain difficulties with focusing the flame of the burner, as a result of which the cut is not uniform.
As a special case of flame cutting, plasma cutting can be considered, which is characterized by a higher temperature, as a result of which the cutting speed increases, which is why the local overheating of the workpiece decreases.
Milling — type of mechanical processing. Finger milling cutters are used for cutting steel sheets. The process is long, the cutting tool is expensive, blunt and often breaks. In the process of work, a significant mechanical effect is exerted on the workpiece, which should be taken into account when choosing the thickness of the workpiece in order to avoid its deformation and destruction.
Water blasting involves the supply of a high-pressure fluid jet containing suspended abrasive particles that destroy the material being processed, giving it the desired shape. The method has a number of advantages — the sample does not heat up at all, it is possible to cut thin sheets stacked in a stack, as a result of which productivity increases. Disadvantages — high cost of operation of the plant, corrosion and difficulties in processing thin sheet metal.
The laser cutting method has advantages over those listed — the ability to process other materials in addition to metals, low cost of operation, the ability to cut very thin workpieces — from 0.2 mm., high speed, precision.
So, for example, an attempt to cut a sheet of plywood with a plasma and even more so with a flame cutter will end in a fire, and waterjet cutting — the problem of how to get rid of the soaked and exfoliated material. Due to the high concentration of the laser beam on a small area, the wood around the cut does not have time to warm up, due to which the excellent quality of the manufactured parts is achieved. Sheets of metal of small thickness cannot be cut mechanically — the cutter will simply break them, the plasma will also not give a good result, since the outgoing hot gases will heat the metal over a large area, followed by its deformation.
In terms of operating costs, the laser machine also compares favorably with competitors — The most common for industrial applications, carbon dioxide lasers have a coefficient of performance (COP) of up to 20%, which is a very worthy indicator among other sources of coherent radiation. In addition, there is no need to constantly change expensive cutters, there is no fuel consumption in the burner or a working fluid for plasma, abrasive material.
This is a short list of the advantages of laser cutting in metalworking.