CO2 lasers are divided into axial flow and transverse flow lasers based on the combination of factors such as gas flow direction and laser resonance output direction. From the design point of view, axial fast flow lasers are relatively easy to obtain the ideal laser mode - TEMOO mode or TEMO1 mode. Therefore, the current mainstream cutting machine tools in the world use axial fast flow CO2 lasers. On this basis, we discuss the factors that affect the processing effect of laser cutting machine.
In the industrial laser application, the application proportion of laser engraving machine and laser cutting machine is as high as 70%, which means that the application of laser cutting technology plays a leading role in the industrial laser application. Therefore, the requirement for laser cutting quality is also the topic that the dividend pays most attention to. Today, experts of Guangyue Laser briefly introduce several major issues that affect the laser cutting quality:
Laser is the heart of laser equipment and plays a decisive role in laser cutting quality. A good laser should have ideal mode, stable power and other elements. There are many kinds of lasers, which can be defined differently from different angles. According to the excited medium, it can be roughly divided into solid state lasers and gas lasers, which use different solid or gas as the medium respectively. For example, the earliest lasers used ruby as the medium. At present, the mainstream laser used for laser cutting is CO2 laser, followed by YAG laser. YAG laser has the characteristics of high photoelectric conversion efficiency and small volume, but it is greatly limited due to its fast loss of energy pump source and high maintenance cost. With CO2 laser, it is easier to obtain ideal laser mode and higher energy. With stable performance and short downtime, it is widely used for cutting various materials.
CO2 lasers are divided into axial flow and transverse flow lasers based on the combination of factors such as gas flow direction and laser resonance output direction. From the design point of view, axial fast flow lasers are relatively easy to obtain the ideal laser mode - TEMOO mode or TEMO1 mode. Therefore, the current mainstream cutting machine tools in the world use axial fast flow CO2 lasers. On this basis, we discuss the factors that affect the processing effect of laser cutting machine.
1、 Incentive mode
CO2 laser generates laser by exciting CO2 gas with electrode. According to the installation position of metal electrode, it can be divided into DC excitation and RF excitation.
2、 Laser frequency
The laser output is divided into pulse output and continuous output. The laser used for cutting and welding mainly adopts pulse output mode. The pulse frequency mainly affects the cutting speed and notch roughness. To obtain high-speed cutting, high frequency is essential. At present, the frequency of CO2 lasers produced by most manufacturers is within 5000Hz.
3、 Beam divergence angle
Strictly speaking, the beam divergence angle does not belong to the laser part, but because the laser mode has a great influence on the far field divergence angle, we will discuss it here. The influence of beam divergence angle on cutting quality is reflected in the width and slope of the incision. The smaller the divergence angle, the narrower the incision degree, the smaller the slope, and the higher the quality.
4、 Laser mode
Laser mode is one of the important factors for laser quality. It can be divided into single mode, basic mode and multi-mode. The fundamental module, TEMOO module, is an ideal dot because its exponents on the X and Y axes are both 0. The laser with TEMOO mode can obtain the smallest beam diameter, the smallest kerf and faster cutting speed due to its small light spot. However, multimode is non zero exponent in XY direction, and its beam quality is poor. It is generally used for welding rather than cutting.
5、 Laser power
Including peak power, energy stability and other elements. Different power can cut through different thicknesses in metal plate cutting. Take 4KW laser as an example, it can cut 20MM thick carbon steel plate, 15MM stainless steel plate, 10MM aluminum alloy; The laser above 5KW can cut 25MM thick carbon steel and 20MM stainless steel. Another indicator of laser power is power stability. Excellent cutting quality must be excellent throughout the incision. Long term production is also a very important test for lasers. The power of DC excited laser is attenuated due to electrode ablation. In addition, some laser vacuum pumps and turbine pumps use lubricating oil for lubrication, which causes the lubricating oil to pollute the laser resonator and shorten the laser life.
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