The laser cutting machine focuses the laser light emitted from the laser into a laser beam with high power density through the optical path system. The laser beam is irradiated on the surface of the workpiece, so that the workpiece reaches the melting point or boiling point, and the high-pressure gas coaxial with the beam blows away the molten or vaporized metal.
As the relative position of the beam and the workpiece moves, the material will eventually form a slit, so as to achieve the purpose of cutting.
1. Vapor cutting. In the process of laser gasification cutting, the temperature of the surface temperature of the material rises to the boiling point temperature so fast that it is sufficient to avoid melting caused by heat conduction, so part of the material vaporizes into steam and disappears, and some of the material is ejected from the bottom of the slit as an auxiliary gas. The stream blows away. Very high laser power is required in this case. In order to prevent the material vapor from condensing on the slit wall, the thickness of the material must not greatly exceed the diameter of the laser beam. This process is therefore only suitable for applications where it is necessary to avoid the exclusion of molten material. This machining is actually only used in very small areas of use of iron-based alloys. This process cannot be used for materials such as wood and certain ceramics, which are not in a molten state and are therefore unlikely to allow the material to re-condensate. In addition, these materials often require thicker cuts. In laser gasification cutting, optimal beam focus depends on material thickness and beam quality. Laser power and vaporization heat have only a certain effect on the optimal focus position. With a certain thickness of the plate, the maximum cutting speed is inversely proportional to the gasification temperature of the material. The required laser power density is greater than 108 W / cm2 and depends on the material, cutting depth and beam focus position. In the case of a certain thickness of the plate, assuming sufficient laser power, the maximum cutting speed is limited by the gas jet speed.
2. Melt cutting. In laser melting and cutting, after the workpiece is partially melted, the molten material is ejected by the airflow. Because the transfer of material occurs only in its liquid state, this process is called laser melting cutting. The laser beam is coupled with a high-purity inert cutting gas to cause the molten material to leave the slit, and the gas itself is not involved in cutting. Laser melting cutting can achieve higher cutting speed than gasification cutting. The energy required for gasification is usually higher than the energy required to melt the material. In laser melting cutting, the laser beam is only partially absorbed. The maximum cutting speed increases with increasing laser power, and decreases almost inversely proportionally with increasing plate thickness and increasing material melting temperature. With a certain laser power, the limiting factor is the air pressure at the slit and the thermal conductivity of the material. Laser melting cuts provide non-oxidized cuts for iron and titanium. The laser power density that produces melting but less gasification is between 104 W / cm2 to 105 W / cm2 for steel materials.
3. Oxidative melting cutting (laser flame cutting) Melt cutting generally uses an inert gas. If it is replaced by oxygen or other active gases, the material is ignited by the laser beam, and a fierce chemical reaction with oxygen generates another heat source, which further heats the material. This is called oxidative melting cutting. . Due to this effect, for structural steels of the same thickness, the cutting rate obtained by this method is higher than that of melt cutting. On the other hand, this method may have worse cut quality than melt cutting. In fact it produces wider kerf, noticeable roughness, increased heat affected zone and worse edge quality. Laser flame cutting is not good when machining precision models and sharp corners (the danger of burning off sharp corners). Pulsed mode lasers can be used to limit thermal effects, and the power of the laser determines the cutting speed. With a certain laser power, the limiting factor is the supply of oxygen and the thermal conductivity of the material.
4. Control fracture cutting. For brittle materials that are easily damaged by heat, high-speed, controlled cutting by laser beam heating is called controlled fracture cutting. The main content of this cutting process is: the laser beam heats a small area of the brittle material, causing a large thermal gradient and severe mechanical deformation in the area, resulting in cracks in the material. As long as a balanced heating gradient is maintained, the laser beam can guide cracks in any desired direction.
Laser cutting processing replaces the traditional mechanical knife with an invisible light beam. It has the characteristics of high accuracy, fast cutting, not limited to cutting pattern restrictions, automatic typesetting to save materials, smooth cuts, and low processing costs. It will gradually improve or replace Traditional metal cutting process equipment. The mechanical part of the laser cutter head has no contact with the workpiece and will not cause scratches on the surface of the workpiece during the work; the laser cutting speed is fast, the cut is smooth and flat, and generally no subsequent processing is required; the cutting heat affected zone is small, the plate deformation is small, and the slit is narrow (0.1mm ~ 0.3mm); no mechanical stress and no shear burrs; high processing accuracy, good repeatability, and no damage to the surface of the material; NC programming, can process any floor plan, can cut the entire board with large format, no need Save time by opening the mold.
1. High precision: suitable for cutting precision parts and fine cutting of various craft characters and paintings. 2. Fast speed: more than 100 times of wire cutting. 3. The heat affected zone is small and difficult to deform. The slit is smooth and beautiful, and no subsequent processing is required. 4. High cost performance: the price is only 1/3 of the similar performance CO2 laser cutting machine, and 2/5 of the CNC punch with the same efficiency. 5. The use cost is very low: only 1/8 to 1/10 of the same type of CO2 laser cutting machine, the cost per hour is only about 18 yuan, and the cost of CO2 laser cutting machine is about 150 to 180 yuan per hour. 6. The follow-up maintenance cost is very low: only 1/10 ～ 1/15 of the similar CO2 laser cutting machine, and 1/3 ～ 1/4 of the CNC punch with the same efficiency. 7, stable performance, to ensure continuous production. The solid YAG laser is one of the most stable and mature products in the laser field. 8. Compared with CNC punch, YAG laser cutting machine has the following advantages: (1) It can complete the processing of various complex structures. As long as it can draw any image on the computer, the machine can complete the processing. (2) No need to open the mold, just make the drawing on the computer, the product can be released immediately, which can quickly develop new products and save costs. (3) YAG cutting machine has an automatic tracking system, so it can complete both plane cutting and various uneven surface cutting. (4) The complicated technology requires that the CNC punch is difficult to complete, and laser cutting can do it. (5) The surface is very smooth, and the product grade is very high, which is difficult for CNC punching machines. (6) The formed box (within thickness of 0.5 meters) needs to be added with holes and grooves. The CNC punch cannot handle it. YAG CNC metal laser cutting machine can solve it.
Metal laser cutting machine applications are very extensive, covering many industries, and is one of the necessary equipment for many companies, including advertising sign production (these are mainly stainless steel LOGO and logo cutting), sheet metal processing (sheet metal Metal processing basically includes all metal materials. These are generally bending, grinding, etc. Cutting is one of the most important processes. The manufacture of chassis and cabinets (this is generally useful for carbon steel or stainless steel, but also mainly for folding. Bending and cutting 2 cutting processes), spring leaf (belonging to the finishing process), subway parts, and the production of elevator housings, machinery and equipment housings, and kitchen utensils (mostly stainless steel), which exceeds the laser The laser cutting machine setup also participated in the production of the Shenqishen-8 spaceship, which actually involved various aspects. Widely used in sheet metal processing, advertising sign making, high and low voltage electrical cabinet production, mechanical parts, kitchenware, automobiles, machinery, metal crafts, saw blades, electrical parts, eyewear industry, spring leaf, circuit board, electric kettle, medical micro Electronics, hardware, knife measuring tools and other industries.