When using the optical fiber laser cutting machine to process the metal plate, usually, the first step is to use the machine to punch a small hole, then it can continue to cut. There are two ways to pierce. Today, I will introduce the optical fiber laser cutting machine to you.
1、 Blasting perforation
After continuous laser irradiation, a pit is formed in the center of the cutting material, and then the oxygen flow quickly removes the molten material and forms a hole. Generally, the hole size is related to the plate thickness, and the average diameter of the sandblasting hole is half of the plate thickness. Therefore, for thicker plates, the diameter of the blast hole is larger than that of the thin plate. Therefore, it is not suitable to use this piercing method on parts with high machining accuracy requirements.
2、 Pulse perforation
Pulse laser with peak power is used to melt or evaporate a small amount of materials. Each pulse laser will only gradually produce a small beam of particles, so it takes several seconds for thick plates to gradually penetrate. After perforation, replace the auxiliary gas with oxygen to cut immediately. In this way, the diameter of perforation is smaller, and the quality of pulse perforation is better than that of blasting perforation. In addition, more reliable gas path control system is required for pulse perforation to realize the switching of gas type, gas pressure and perforation time.
In the case of pulse piercing, in order to improve the quality of the notch, we must pay attention to the transition technology from pulse piercing when the workpiece is stationary to constant cutting. At present, in industrial production, we mainly adopt the method of changing the average laser power to improve the perforation effect. The specific method is to change the pulse width, pulse frequency, or both.