The principle, characteristics and application of laser cutting

4. Application range of laser cutting

In industrial production, laser cutting technology is one of the most widely used processing methods for laser processing, accounting for about 60% of the entire material laser processing application.

Most laser cutting machines are controlled by numerical control programs or made into cutting robots. As a precision processing method, laser cutting can cut almost all materials, including two-dimensional or three-dimensional cutting of thin metal plates. Laser cutting is widely used in electrical manufacturing, transportation machinery, petrochemical industry, automobile manufacturing, engineering machinery, medical equipment, decoration, packaging industry and so on.

In the field of automobile manufacturing, the laser cutting technology of space curve such as car roof window has been widely used. The German Volkswagen company uses a 500W laser to cut complex body sheets and various curved parts. In the aerospace field, laser cutting technology is mainly used for cutting special aviation materials, such as titanium alloy, aluminum alloy, nickel alloy, chromium alloy, stainless steel, beryllium oxide, composite materials, plastics, ceramics and quartz. The aerospace parts processed by laser cutting are engine flame cylinder, titanium alloy thin-walled casing, aircraft frame, titanium alloy skin, wing length analysis, tail wall panel, helicopter main rotor, space shuttle ceramic insulation tile, etc.

Laser cutting technology is also widely used in the field of non-metallic materials. The power required for laser cutting is relatively low, and under normal circumstances, continuous CO2 lasers below 1kW are sufficient to cut thin workpieces. It can not only cut materials with high hardness and brittleness, such as silicon nitride, ceramics, quartz, etc., but also cut flexible materials, such as cloth, paper, plastic board, rubber, leather, etc., such as clothing cutting with laser, can save 10%~12% of clothing material, improve the efficiency of more than 3 times. The energy density of the laser beam is slightly lower than the energy density of the electron beam, the cutting ability of the two beams is basically the same compared with the electron beam cutting, laser cutting in the atmospheric atmosphere can cut the thickness of 25mm metal, automatic cutting equipment can be cut at a high speed, the incision is very narrow, the incision Angle is almost vertical, the incision quality is excellent. Table 4.3 lists the laser cutting and plasma cutting, oxygen-acetylene cutting more suitable for CO2 laser cutting products can be generally summarized into the following three categories. The first type: metal sheet metal parts that are not suitable for manufacturing molds from a technical and economic point of view, especially workpiece with complex wheel shape and small batch, such as low carbon steel plates with a thickness of 12mm, stainless steel plates with a thickness of 6mm, and non-metallic materials with a thickness of 20mm, in order to save the cost and cycle of manufacturing molds. Typical products using CO2 laser cutting are automatic elevator structural parts, elevator panels, machine tools and food machinery covers, various electrical cabinets and switchgear, textile machinery parts, construction machinery structural parts, large motor silicon steel sheet. The cutting of three-dimensional space curves has also been applied in the automotive and aviation industries. The second category: decoration, advertising, service industry with stainless steel (general thickness of 3mm) or non-metallic materials (general thickness of 20mm) patterns, marks, fonts, such as art photo album patterns, companies, units, hotels, shopping mall signs, stations, docks, public places of all kinds of text. The third category: special parts requiring uniform slit. The most widely used typical part is the die-cutting plate used in the packaging and printing industry, which requires a slot with a slit width of 0.7~0.8mm to be cut on the wood template with a thickness of 20mm, and then a blade is inlaid in the slot, and a variety of printed graphics are cut off the packaging box using the fashion die-cutting machine. Another new field of domestic application in recent years is the oil screen seam pipe, in order to prevent sediment from entering the pump, the alloy steel pipe with a wall thickness of 6~9mm is cut out 0.3mm wide uniform slit, and the diameter of the hole at the cutting perforation can not be greater than 0.3mm.

From the type of production units, one is large and medium-sized manufacturing enterprises, the products produced by these enterprises have a large number of plates need to be cut, cutting, with strong economic and technical strength; The other type is the processing station, which is specialized in undertaking laser processing business, and has no leading products of its own, its existence can meet the processing needs of some small and medium-sized enterprises, and play a role in promoting and demonstrating the application of laser cutting technology. In the 1980s, China's laser processing stations were mainly engaged in laser heat treatment work, and laser cutting gradually increased after the 1990s. In recent years, more and more enterprises have adopted CO2 laser cutting technology.

In addition to the above applications, laser cutting is also continuing to expand its application areas, as follows:

1)The use of 3D laser cutting system or configuration of industrial robots, cutting space curves, the development of a variety of 3D cutting software to speed up the process from drawing to cutting parts.

2) In order to improve production efficiency, research and development of various special cutting systems, material conveying systems, linear motor drive systems, etc., the current cutting speed of the cutting system has exceeded 100m/min.

3) In order to expand the application of construction machinery, shipbuilding industry, etc., the thickness of cutting low carbon steel plate has exceeded 30mm, and special research is made on the process technology of cutting low carbon steel plate with nitrogen to improve the quality of cutting thick plate incision.

Expanding the application field of CO2 laser cutting and solving some technical problems in new applications are still important topics for engineers and technicians.