How to improve laser cutting quality through focus position
25 Mar , 2021
In recent years, laser cutter manufacturers have paid more and more attention to the stability of laser cutter. The stability of the laser cutter is closely related to several important parts.
In recent years, laser cutter
manufacturers have paid more and more attention to the stability of laser cutter. The stability of the laser cutter is closely related to several important parts. It is equipped with high-quality parts. It is naturally very stable when used.
This problem makes many customers hesitate between imported and domestic laser cutter. Some users even worry that the stability of the domestic laser cutter will decrease after a long time of work.
In fact, these worries are unnecessary. Domestic laser equipment already has a good foundation and R&D technology. In fact, the performance of laser cutter is not necessarily worse than imported ones, so the stability of laser cutter cannot be promoted. This requires continuous technology. Improvements and improvements will gradually improve. At the same time, whether the laser cutter is stable during use depends on your post-maintenance and working environment.
How to determine the focus position to make laser cutting
In the laser cutting process, if the focus position is different, the cutting quality will be different. In order to improve the quality of the laser cutter, it is very important to adjust the focus position of the laser cutter.
In today's rapid economic development, laser cutter have quietly entered people's lives. With the continuous improvement of people's material level, especially the continuous refinement of technology, it is inseparable from the continuous precision of laser cutting and engraving.
The laser cutter for high-precision and large-thickness parts must master and solve several key technologies. Focus position control technology is one of them.
The main advantage of the laser cutter is the high energy density of the laser beam, so the focal spot diameter should be as small as possible to produce narrow slits. Because the smaller the focal depth, the smaller the focal spot diameter. For high-quality cutting, the effective focal depth is also related to the lens diameter and cutting material. Therefore, it is very important to control the position of the focus relative to the surface of the material to be cut.
We analyzed the cutting focus from three aspects of different materials and different requirements.
First, the cutting focus is on the surface of the workpiece:
This mode is also called zero focal length, and is usually used for cutting workpieces such as SPC, SPH, and SS 41. When in use, the focus of the tool is close to the surface of the workpiece. In this mode, the finish of the upper and lower surfaces of the workpiece is different. Generally speaking, the cutting surface near the focus is relatively smooth, while the lower surface far away from the cutting focus is rough. In practical applications, the mode should be determined according to the process requirements of the upper and lower surfaces.
Second, the cutting focus is on the workpiece:
This is also called positive focus. When the workpiece you need to cut is stainless steel or aluminum plate, the method of cutting points is often used on the workpiece. However, due to the influence of the focusing principle, one disadvantage of this method is that the cutting amplitude is larger than the cutting point on the surface of the workpiece. At the same time, the cutting airflow required by this mode is large, the temperature is sufficient, and the cutting and piercing time is slightly longer. So when you choose the material of the workpiece, it is mainly stainless steel or high-hardness aluminum lamp.
Third, the cutting focus is on the workpiece:
In this way, we also become a negative focus, because the cutting point is not on the surface of the cutting material or inside the cutting material, but on the cutting material. This method mainly uses materials with high cutting thickness. In this way, the focus is located above the cutting material, mainly due to the large cutting range required by the thick plate, otherwise the oxygen delivered by the nozzle will easily lead to insufficient cutting temperature. However, one disadvantage of this method is that for high-precision cutting, the cutting surface is relatively rough, which is not practical.
Since the laser power density has a great influence on the cutting speed, the choice of lens focal length is also an important issue. After the laser beam is focused, the spot size is proportional to the focal length of the lens. After the beam is focused by a short focal length lens, the spot size is small, and the power density at the focal point is very high, which is beneficial to the cutting of materials. But its disadvantage is that the adjustment range of the focal depth is very small, which is generally suitable for high-speed cutting of thin materials. Due to the large focal depth of the long focal length lens, as long as there is sufficient power density, it is suitable for cutting thick workpieces.
The adjustment of the focus is very difficult for the operator. Laser cutter so we should learn more. When the focus is in the best position, the cutting seam is the smallest and the efficiency is the highest. The best cutting speed of fiber laser cutting equipment
can get the best cutting effect.