Compared with other thermal cutting methods, laser cutting is characterized by fast cutting speed and high cutting quality. When oxygen is used as a processing gas, the cutting edge is slightly oxidized. For plates with a thickness of up to 4mm, nitrogen can be used as the gas for high-pressure cutting.
The plates with a thickness of more than 10mm can be used to apply the special plate to the laser and oil can be applied to the surface of the workpiece in the process in order to get better cutting quality. For brittle materials prone to heat damage, high speed and controllable cutting through laser beam heating are called controlled fracturing cutting. in the process of oxidation melting and cutting with two heat sources, if the combustion rate of oxygen is higher than that of the laser beam, the slit appears wide and coarse. the surface of the material is heated to the point of ignition rapidly under the irradiation of the laser beam, and with the intense combustion reaction with oxygen, a large amount of heat is released.
Each of these welding processes have multiple practical uses within the manufacturing industry. In the hands of the right professional, the technology can help create customized pieces for various applications. This process is characterized by high efficiency and high welding speeds. This process is used in applications requiring deeper welds or where several layers of material have to be welded simultaneously.
The laser beam continues to irradiate along the edge of the seam, and the melting material continues or pulsates been blow away through the cracks. The holes are surrounded by molten metal walls, and the auxiliary airflow along the shaft of the beam takes away the molten material around the hole. Laser vaporization is used to cut thin metal materials and non-metallic materials (such as paper, cloth, wood, plastic and rubber, etc.).
（2）Various special cutting systems, material conveying systems, linear motor drive systems are been developed in order to improve production efficiency. In order to prevent the sediment from entering the pump, a uniform slit of 0.3mm wide was cut on the alloy steel tube with a thickness of 6~9mm. The cutting technology is difficult, but there are still many factories adopt this method and put into production. The most widely used typical parts are the die-cutting plate used in the packaging and printing industry. It requires a slot with a width of 0.7-0.8mm on a wooden plate of 20mm thickness and inserts a blade in the slot.
Laser welding uses a highly concentrated beam of light on a very tiny spot so that the area under the laser beam absorbs the light and becomes highly energetic. As powerful laser beams are used, the electrons in the area get excited to a point where the material melts as the result of the atoms breaking the bonds with each other. If you require flexible processing of sheet metal and tubes, TRUMPF can offer the ideal machine tools and laser systems in a wide range of applications.
Through his articles, users can always easily get related problems solved and find what they want. Based on the years of cutting experience, the following nine criteria are summarized, which can be used as a reference for customers. Laser cutting equipment costs high, which means a high one-time investment. Both materials have high reflectivity and very good thermal conductivity. Only when the system is equipped with “reflective absorption” device can the aluminum be cut, otherwise the optical component will be destroyed by reflection. The use of nitrogen to get the edge of non-oxidized and no burr which does not need to be dealt with again.
The comparison of laser cutting, oxyacetylene cutting and plasma cutting methods is shown in Table 1. The cutting material is low carbon steel plate with 6.2mm thickness. Of course, for high-reflectance materials such as gold, silver, copper, and aluminum, they are also good heat transfer conductors, so laser cutting is difficult and can’t even be cut. When the steel is cut, oxygen is used as the auxiliary gas and molten metal to produce exothermic chemical reaction oxidation material, while helping to blow away the slag in the slit. Laser cutting can achieve better cutting quality due to the small laser spot, high energy density and fast cutting speed. It is obvious that using oxygen as an auxiliary gas can achieve high cutting speed compared with the inert gas.
The cutting edge is affected very small by the heat, and there is no deformation of the workpiece. At this point, the heat input of the beam is far more than the part of the material reflected, transmitted or diffused. When the cut product is the final product, there is no subsequent process, and it is necessary to use a protective gas, such as a craft product. The key considerations are the cost of cutting and the requirements for the product. If you want to cut stainless steel of 12mm, or thicker to 25mm, the pressure is required to be 2Mpa or higher.
For example, the cutting speed is usually lower when the small circle and sharp angle are cut. At this time, the NC system can reduce the cutting power according to the actual cutting speed, and can get excellent cutting precision and sectional quality. ⑸ The wavelength of the optical fiber laser is 1.06μm, is more easily absorbed by the metal material compared with the wavelength of CO2 which is 10.6 μm and is especially beneficial for sheet metal cutting. At the same time with the aid of high-speed airflow which coaxial with the laser beam to blow away molten material, so as to realize the cutting of the workpiece.
For example, a laser can have 300 W average power and 6000 W peak power. These lasers are often referred to as Quasi Continuous Wave Fiber Lasers. As the name states, the Continuous Wave lasers deliver a continuous, uninterrupted output. This output can have an upslope (soft-start) when switched on, an energy modulation while active, and a downslope when switched off . Of course, this type of laser can also be switched on and off to create pulses.
The properties of the material near the slit are also almost unaffected. And the workpiece deformation is small, the cutting precision is high, the geometry of the slit is good, and the shape of the cross-section of the slit is a regular rectangle. ② The surface of the cutting surface is clean and beautiful, the surface roughness is only a few tens of microns, even laser cutting can be used as the last procedure, no need machining, the parts can be used directly. ① The laser cutting incisions are narrow, and the cutting edges are parallel and perpendicular to the surface.
When cutting flammable materials such as cotton, paper, the inert gas is been used. As long as the balanced heating gradient is maintained, the laser beam can guide the cracks in any desired direction. The laser beam heats the small area of the brittle material, causing the large thermal gradient and serious mechanical deformation in the region, causing the material to crack. It is estimated that when the steel is cut, the amount of heat released by the oxidation is about 60% of the total energy required for cutting.
The influence of laser process parameters on the laser welding quality of ultra-thin stainless steel sheet was analyzed. Stainless steel is a very common material in our life and production. Laser welding offers a fast, economical and contact-free alternative for welding a wide variety of metals in virtually every industry. Whether you require high processing speed, complex weld geometries or multi-layer joints, IPG provides unique solutions for a diverse range of welding applications. As a sophisticated machining method, laser cutting can cut almost all materials, including 2D or 3D cutting of thin metal sheets.
I believe that you have a preliminary understanding of some of the characteristics of the three auxiliary gases when you read here. The freshman can also use this rule as the basis for selecting auxiliary gases. The amount of air pressure that can be used for various types of auxiliary gases is different. It seems that you have tried various plates, with various gases, various air pressures, different powers, etc… and then it seems that you’re still very confused about it. Fiber Laser cutting equipment usually adopts device with computerized digital control technology .
On the one hand, the gas is produced by the cutting of metal, and the oxidation reaction occurs, which gives off a lot of oxidation heat. The laser fusion cutting does not require the complete vaporization of the metal, the required energy is only 1/10 of the vaporization. When the power density of the incoming laser beam exceeds a certain value, the material inside the beam irradiation point begins to evaporate and then forming a hole. The heat of vaporization of materials is usually very large, so the laser vaporization requires a large amount of power and power density. Some metals use oxygen to form an oxide film on the cutting surface during cutting, and nitrogen can be used to prevent oxidation-free cutting of the oxide film.