The principle of laser cutting in sheet metal machining


The principle of laser cutting of sheet metal processin […]

The principle of laser cutting of sheet metal processing knowledge, laser cutting is scanned surface by using laser beam with high power density, in a very short period of time will be heating the material to thousands and tens of thousands of degrees Celsius, the material melting or vaporization, and high pressure gas to melting or vaporization of material from the slit blow away, to cut the material for the purpose of.
Laser cutting, because the invisible beam is used instead of the traditional mechanical knife, the mechanical part of the laser cutting head is not contacted with the work. It will not scratch the surface of the work. The laser cutting speed is fast, the incision is smooth and smooth, and there is no need for subsequent processing.
The cutting heat affected zone is small, the deformation is small, narrow kerf (0.1mm~0.3mm); incision without mechanical stress, shear free burr; high machining accuracy, good repeatability, no damage to the material surface; NC programming and machining of arbitrary planar graphs, the whole plate large format cutting, no need to open mold time saving.
Laser cutting is mainly CO2 laser cutting, laser cutting CO2 with CO2 focusing mirror laser beam focusing on the surface of the material to melt materials, with compressed gas and laser beam coaxial blow melted material, and the laser beam and the materials along a certain trajectory for the relative motion, thus forming a slit shape.
The obvious advantages of CO2 laser cutting technology than other methods are: (1) the cutting quality is good. The width of the incision is narrow (generally 0.1--0.5mm), the accuracy is high (the general center distance error is 0.1-0.4mm, the profile error is 0.1-0.5mm), and the surface roughness of the notch is good (generally Ra is 12.5-25 m m).
(2) the cutting speed is fast. For example, using 2KW laser power, 8mm thick carbon steel cutting speed is 1.6m/min; 2mm thick stainless steel cutting speed is 3.5m/min, heat affected zone is small, and the deformation is very small. (3) clean, safe and pollution-free. The operating environment of the operator is greatly improved. Of course, for accuracy and surface roughness, CO2 laser cutting can not be more than electrical processing. For cutting thickness, it is difficult to achieve the level of flame and plasma cutting.
The laser cutting process is varied, which is melting cutting the incident laser beam power density exceeds a certain value, so that the internal material at the beam point began to evaporate, the formation of holes; vaporization cutting is using high power density laser beam heating, avoid melting caused by heat conduction, so part of the material vaporized into steam oxidation disappeared; melt cutting is ignited in materials irradiated by laser beam, violent chemical reaction generates another heat and oxygen;