The laser cutting device can cut stainless steel below 4mm, and oxygen can be cut into 20mm thick carbon steel in the laser beam, but after oxygen cutting, a thin oxide film is formed on the cutting surface. The maximum thickness of the cut can be increased to 20 mm, but the dimensional error of the cutting member is large.
The price of laser cutting equipment is quite expensive, about 1.5 million yuan. However, the use of such equipment in large production is still feasible due to the reduced cost of subsequent processing. Since there is no tooling cost, laser cutting equipment is also suitable for the production of small quantities of parts of various sizes that were previously unworkable. Currently, laser cutting equipment typically employs a computerized digital control (CNC) device that allows the use of telephone lines to accept cutting data from computer-aided design (CAD) workstations.
Laser cutting of metal materials
Almost all metallic materials have a high reflectivity for infrared energy, but CO2 lasers that reflect a 10.6um beam in the far-infrared region have been successfully applied to laser cutting of many metals. The initial absorption rate of metal to 10.6um laser beam is only 0.5%-10%, but the focused laser with a power density of more than 10^6W/cm^2 can quickly melt the surface in the microsecond time when it is irradiated on the metal surface, and absorb most of the metal in the molten state. A sharp rise, generally can be increased to 60% -80%.
The modern laser cutting system can cut the maximum thickness of carbon steel plate to nearly 20mm. The cutting of carbon steel by gasification melting cutting mechanism can be controlled within a satisfactory width range. For the low carbon steel cutting heat affected zone can not be considered, and the slit Smooth, smooth, good verticality, phosphorus and sulfur segregation zone is prone to trimming and erosion. The quality of high carbon steel trimming is slightly improved, but the heat affected zone is also slightly enlarged.
2. Stainless steel
The gasification exothermic reaction in stainless steel laser cutting process is not as strong as that of carbon steel. Therefore, the cutting speed is slightly slower than that of ordinary steel of the same thickness. The stainless steel can be cut with inert gas to obtain gas-free trimming, which can be directly used for welding. However, the cutting speed and oxygen as an auxiliary gas are about 50% lost.
3. Alloy steel
In the possible range of laser power, as long as the process parameters are properly controlled, it is not very difficult to obtain a straight and non-stick slag. However, for high-speed tool steel and hot-mould steel containing tungsten, there is a melting candle stick when laser cutting. The slag phenomenon occurs.
4. Aluminum and alloy
Aluminum cutting is a melting and cutting mechanism. The auxiliary gas used is mainly used to blow away the molten product from the cutting zone. Usually, the quality of the cut surface is obtained. Sometimes the slag adheres to the back of the slit along the trimming edge. In view of the prevention of surface microcracks, aluminum laser cutting requires a high power density, which is hindered by the high reflectivity of the 10.6 um wavelength beam.
5. Copper and alloy
Pure copper (copper) can't be cut with CO2 laser beam because of its high reflectivity. Cutting copper (copper alloy) requires high power, and the auxiliary gas can cut thinner plates with air or nitrogen. The back of the slit sometimes adheres to a small amount of slag. Since this material has a high reflectance to the 10.6 um infrared beam, the optical device is greatly damaged, and laser cutting is not recommended.
6. Titanium and alloy
Pure titanium can well couple the focused laser beam into heat energy. When the auxiliary gas uses oxygen, the chemical reaction is fierce, and the cutting speed is fast, but it is easy to generate oxidized dust on the cutting edge, which will cause over-burning. For the sake of safety, air is used. As an auxiliary gas, it is good.
7. Nickel alloy
Nickel alloys, also known as superalloys, come in many varieties, most of which enable oxidative melt cutting.
Laser cutting of non-metallic materials
The 10.6um wavelength CO2 laser beam is easily absorbed by non-metallic materials. The poor thermal conductivity and low evaporation temperature allow the absorbed beam to be transmitted almost entirely into the material and instantaneously vaporized at the spot to form the initial hole. , enter a virtuous cycle of the cutting process.
2.1 organic materials
2.1.1 Dipping (polymer)
Laser cutting has a large absorption force for plastic processing, because the laser can perform high-speed non-contact cutting on any complex shape workpiece. Laser as a high-power density strong heat source, quickly evaporates the glue, destroys the polymer chain of the material, and implements Cutting.
Low-soluble plastic; under the correct control process, burr-free can be obtained. The bottom of the bubble is cut and smooth and smooth.
High-strength plastics; in order to destroy its strong connecting chain, a strong beam power density is required, and combustion occurs during cutting, and the trimming forms different degrees of carbonization.
Polyvinyl chloride or polyethylene; pay attention to prevent the generation of harmful gases during the cutting process, prevent the machine from rusting, the cut section is brown, and there will be fiber filaments.
The material is non-contact during cutting, and there is no need to worry about the extension and deformation of the work when cutting, and the cutting edge is prevented from sticking.
The laser can effectively cut wood. Laminates. Wood chips. No sawdust. The auxiliary gas must use inert nitrogen to prevent the material from burning.
2 inorganic materials
1.2. 1 Quartz
Quartz materials with lower thermal expansion coefficient are more suitable for laser cutting, with good trimming quality and smooth cut surface.
For most glasses, cracks are generated by laser thermal shock.
The ceramic laser cutting mechanism is controllable fracture, focused spot, super-directional heating gradient and high mechanical application force, so that ceramics such as almost no plastic material generate small cracks, cracks continue to generate light spots, and finally ceramics Cut off, do not use high power with CO2 laser beam, otherwise cracks will occur and the cutting will fail.
Different types of stone materials contain moisture, and moisture is caused by explosion due to rapid heating of the laser beam.