With the rapid development of high-power fiber laser manufacturing technology and the continuous improvement of numerical control technology, the application of fiber laser processing equipment in sheet metal cutting has expanded rapidly in recent years. According to market feedback information, as well as the thickness of the steel plate, the cutting quality and the sales price of the cutting equipment, the market application group of sheet metal processing is subdivided, especially small and medium-sized enterprises in this field urgently need a large range of sheet thickness and good cutting quality , A complete set of processing equipment for high-power fiber laser cutting machine.
What are the difficulties in cutting thick plates with a fiber laser cutting machine
1. The slit is too narrow and the heat loss increases. The reduction in cutting speed increases the heat loss of the cutting area. The main form of heat loss is heat conduction. The greater the thickness, the greater the heat transfer loss and the slower the cutting speed. Although the laser penetrates the slab and a large amount of slag adheres to the bottom of the slab, the material removal at the bottom of the slit becomes inconsistent. The formation of slag is due to the low average cutting temperature at the bottom of the slot, while the low temperature is due to the large energy loss. In this case, the quality of the slot is usually not high.
2. The diameter of the fiber laser spot is small and the focal length is limited. When the fiber laser cuts medium and thick plates, although the laser power density can be maintained at the cutting depth, the beam diameter is small and the slit is thin, which is not conducive to cutting and slagging. This puts forward higher requirements on the mode of the fiber laser and the collimation and range of the spot beam, and also brings great difficulties to the processing quality of the fiber laser cutting metal plate.
3. The role and influence of auxiliary gas quality and pressure. Take oxygen as an example; the oxygen laser plays an indispensable role in the cutting of carbon steel medium and thick plates. The laser irradiates a small hole on the surface of the workpiece. When the laser beam moves in the cutting direction, there is oxidized melt around the small holes and slits. The purity and pressure of oxygen have a great influence on laser cutting. The oxygen with insufficient impurity content and insufficient pressure cannot provide enough energy to form a high-flow melt at the bottom of the slit, thereby reducing the cutting quality and cutting speed. By measuring the quality and auxiliary gas pressure at different slit positions, the narrow slits found will deteriorate the influence of the auxiliary gas, and the cutting quality is more difficult to maintain, thereby ensuring proper slit width, auxiliary gas quality and gas pressure control. This has a great influence on the quality of cutting.
4. The difference in geometry determines the quality of bending cutting. When laser cutting thick plates, the inclination of the melting front is obvious, which leads to a decrease in the laser absorption coefficient of the material, thereby increasing the cutting power, reducing the cutting speed, and ensuring the cutting quality.
Fiber laser cutting machine will be widely used in the cutting field due to its high spot conversion rate, high cutting precision, flexible processing ability, good cutting quality, strong adaptability and other advantages. In addition, by continuously researching high-performance fiber lasers, developing advanced optical cutting methods and supporting equipment, finding the best cutting parameters under various cutting conditions, improving cutting safety, will bring a wider range of fiber laser cutting. Application to truly realize high-efficiency, energy-saving and precise cutting.