The Peculiarities of Laser Cutting Laser cutting is a technology that uses a laser to cut materials where complex contours demand precise, fast and force-free processing. It is typically used for industrial manufacturing applications. Lasers create narrow kerfs and thus achieve high-precision cuts. This method does not show any distortion. In many cases post-processing is not necessary as the component is subjected to only little heat input and it can mostly be cut dross-free. It may be interesting to know about the peculiarities of laser cutting, its benefits and different types of cutting processes.
Almost all kinds of metals can be laser cut. Mild steel, stainless steel and aluminum are the most common applications. Other laser cut parts are made of wood, plastics, glass and ceramics. Compared with alternative techniques like die cutting, laser cutting is cost-efficient for small-batch production. The big benefit of laser cutting is the localised laser energy input that provides small focal diameters, high feed rates and minimal heat input.
Among the advantages of laser cutting over mechanical cutting one can name easier handling and reduced contamination of the work piece, since there is no cutting edge which can become contaminated by the material or contaminate the material. Precision may be better, since the laser beam does not wear during the process. there is also a reduced chance of deforming the material that is being cut, as laser systems have a small heat-affected zone. some materials are also very difficult or impossible to cut by other cutting methods.
There are three different laser cutting processes: flame cutting, fusion cutting and sublimation cutting. while making a decision which process to choose a person should consider the cut geometry, cycle time, system technology and, above all, the material the piece is made of. In flame cutting, oxygen is used as the cutting gas. The oxygen is blown into the kerf. there, the heated metal reacts with the oxygen. It begins to burn and oxidises. The chemical reaction releases large amounts of energy, up to five times the laser energy, and assists the laser beam. Flame cutting makes it possible to cut at high speeds and handle jobs involving thick plates such as mild steel with thicknesses in excess of thirty millimetres.
Laser fusion cutting typically presupposes using inert gases, nitrogen or argon, for cutting higher alloyed steels and aluminum. The gas is blown through the kerf. This means that they do not react with the molten metal in the kerf. they simply blow it out toward the bottom. Simultaneously, they shield the cut edge from the air. The great advantage of this type of laser cutting is that cut edges are oxide free and do not require further treatment. nevertheless, the laser beam must supply all of the energy needed for cutting. for this reason, cutting speeds as high as those in flame cutting can be achieved only in thin sheets.
In the laser sublimation cutting process the idea is to use the laser to vaporise the material with as little melting as possible. The material vapour creates high pressure that expels the molten material from the top and bottom of the kerf. The process gas, nitrogen, argon or helium, serves solely to shield the cut surfaces from the environment. It ensures that the edges remain oxide free. This process is rarely used in sheet metal fabrication. its use, however, becomes attractive in applications involving particularly delicate laser cutting work.
In recent years, the increase in laser cutting has been evident. The improvements in accuracy, edge squareness and heat input control made it possible for laser cutting to replace other profiling techniques such as plasma cutting and oxy-fuel cutting almost completely.