Analyze the importance of air pressure in the laser cutting process
Published: 2019-11-13

In the process of laser cutting, the pressure of the auxiliary gas has a significant influence on the cutting results. A laser cutting machine focuses light into a high-density beam, which, when delivered to the work surface, generates sufficient heat to melt the material. Coupled with high-pressure gas coaxial with the beam, the melted metal is directly removed, thus achieving the purpose of cutting. This illustrates that laser cutting processing is fundamentally different from mechanical processing using machine tools. So-called laser cutting involves irradiating the workpiece surface with a laser beam, releasing energy to melt and evaporate the workpiece, achieving the purpose of cutting and engraving. It features high precision, fast cutting, no limitation on cutting patterns, automatic layout to save materials, smooth cuts, and low processing costs. It will gradually improve or replace traditional metal cutting process equipment. The auxiliary gas must have sufficient pressure to thoroughly remove the waste residue generated during cutting. Generally, the pressure should be reduced when cutting thicker workpieces, as residue adhering to the workpiece can damage the cutting edge. Increasing gas pressure can advance the cutting speed, but once it reaches a higher value, further increasing gas pressure can actually cause a decrease in cutting speed. A laser cutting machine focuses light into a high-density beam, which, when transmitted to the work surface, generates sufficient heat to melt the material. Additionally, high-pressure gas coaxial with the beam directly removes the molten metal, thus achieving the purpose of cutting. This illustrates that laser cutting is fundamentally different from mechanical machining using machine tools. Laser cutting, as the term is used for laser cutting machines, involves irradiating the workpiece surface with a laser beam, releasing energy to melt and vaporize the workpiece, thus achieving the purpose of cutting and engraving. It features high precision, fast cutting, no limitation on cutting patterns, automatic layout to save material, smooth cuts, and low processing costs. It will gradually improve or replace traditional metal cutting process equipment. The reason for the decrease in cutting speed under high auxiliary gas pressure can be attributed to the enhanced cooling effect of high gas flow velocity on the interaction zone, as well as the interference of intermittent shock waves present in the gas flow with the cooling of the laser interaction zone. Uneven pressure and temperature in the gas flow can cause changes in the density of the gas flow field. Such density gradients lead to changes in the refractive index within the field, which interferes with the focusing of beam energy, resulting in refocusing or beam divergence. This interference can affect melting efficiency and sometimes change the pattern structure, leading to a decrease in cutting quality. If the beam divergence is too severe, it can cause the beam spot to become too large, resulting in serious consequences such as ineffective cutting. To avoid adverse effects of high-speed airflow on segmentation performance, it is conceivable to alter the overall pressure distribution within the airflow. This change in airflow pressure distribution causes the melting process to occur in the central low-pressure zone, while the adjacent high-pressure zones around it can be increased to sufficient momentum (impact force) to ensure more effective slag removal. The laser cutting machine focuses light into a high-density beam, which, when transmitted to the work surface, generates sufficient heat to melt the material. Coupled with the high-pressure gas coaxial with the beam, which directly removes the molten metal, the cutting objective is achieved. This demonstrates that laser cutting processing is fundamentally different from mechanical processing using machine tools. Since the intermittency of the high-pressure zones does not interfere with the speed of light, melting efficiency is also improved. image