Laser cutting processing common problem
by：HENRY PARTS 2021-04-13
Laser cutting machining common problems common process and problem analysis fusion cutting perforation technology input laser power density, high energy, beam point material internal evaporated, formed hole, hole surrounded by a molten metal, and the beam coaxial auxiliary air holes around the molten material. Artifacts, holes by synchronous transverse cutting direction to form a complete cutting kerf width. For hot cutting technology, generally must adopt the punch a small hole in the plate and then begin from the holes by laser cutting method, only a handful of machining can start on the plate edge when machining. For not punching device of laser cutting machine has two kinds of the basic ways of perforation: blasting perforation: material after continuous laser irradiation in the center of the formation of a pit, and coaxial laser oxygen flow quickly remove the molten material to form a hole. Processing head and processed materials according to the continuous dot relative motion paint with good graphics in advance, and will combine processing ChengXiang to the shape of the object. When cutting, a beam with coaxial airflow by cutting head, will melt or gasification materials by incision of the bottom blown out ( Note: if the blown gas and thermal effect was cut material reaction, this response will provide additional energy required for cutting; Air flow and cooling has been cut surface, reducing heat affected zone and ensure that the role of the focusing lens is not contaminated) 。 Note that the cutting is not suitable for this kind of control fracture acute Angle and the Angle of cutting edge cutting seam. Heavy cutting closed shape is not easy to achieve success. Control fracture cutting speed is fast, don't need too much power, otherwise it will cause the workpiece surface melting, destroy the cutting edge. The main control parameters are laser power and spot size. 1, the vaporization cutting. Under the high power density of laser beam heating, the material surface temperature to the boiling point temperature speed is so fast, enough to avoid melting caused by heat conduction, so part of the material vaporized into steam, part of the material as the ejecta from the bottom of the kerf width auxiliary gas flow blown away. Some can't melt material, such as wood, carbon materials, and some plastic is cut by the vaporization cutting method. Vaporization cutting process, the steam with you melt particle and flush debris, forming holes. Vaporization process, about 40% of the material into steam disappeared, and 60% of the material in the form of molten drops by air flow away. 2, melt cutting. When the incident laser power density is more than a certain value, the beam point material internal evaporated, formed holes. Once the holes to form, which will serve as a bold absorb all of the incident beam energy. Hole is surrounded by a wall of molten metal, and then, and beam coaxial auxiliary air holes around the molten material. With workpiece moving, the hole by the synchronous transverse cutting direction to form a cut seam. To continue along the seam at the forefront of laser beam irradiation, continuous or pulse melting materials from being blown away from the seam. 3, oxidation melting cutting. Melt cutting generally use inert gases, if replaced with oxygen or other reactive gas, was lit materials under the irradiation of laser beam, and the chemical reaction of oxygen violent and produce another source of heat, called oxidation melting cutting. Description: (as follows 1) Material surface under the irradiation of laser beam heats up quickly to the ignition temperature, intense combustion reaction with oxygen, then let out a lot of heat. Under the effect of the heat, the material forming inside the hole filled with steam, and holes for molten metal around the wall. （ 2) Combustion substances into slag control of oxygen and the combustion rate of the metal and arrive at the same time, through slag, oxygen diffusion of the fast ignition front also has great influence on combustion rate. The higher the oxygen flow rate, combustion chemistry and remove slag much sooner. Oxygen flow rate is not, of course, the higher the better, because the velocity of reaction product that is too fast will lead to slitting the exit of metal oxide rapid cooling, but also the cutting quality.