While for other basic process parameters, such as laser power, cutting speed, auxiliary gas pressure, gas flow, the distance between cutting nozzle and workpiece, focal length and defocus, there is an adjustment range of cutting parameters, and different parameter combinations will significantly affect the cutting quality.Īmong these parameters, laser power and cutting speed are a pair of interrelated and constrained parameters, which are not only easy to adjust, but also the main factors affecting the cutting quality. Some of the influencing factors are predetermined in the actual laser cutting production, such as the performance of the whole laser, beam quality, material and thickness of the processed object, etc Laser cutting is a very complex thermophysical process, which is affected by many factors. (2) Process parameters of CO 2 laser cutting However, with the increase of plate thickness, the perforation time also increases. In the cutting of medium and thick plates, pulse vibration is generally used. The actual results show that the best effect is to change the pulse width and frequency at the same time. There are three specific methods: changing the pulse width Change the pulse frequency Change the pulse width and frequency at the same time. It is more realistic to change the average laser power in plate processing. Theoretically, the cutting conditions of the acceleration section can usually be changed, such as focal length, nozzle position, gas pressure, etc., but in fact, it is unlikely to change the above conditions due to the short time. In the case of pulse perforation, in order to obtain high-quality incision, the transition technology from pulse perforation when the workpiece is stationary to constant speed continuous cutting of the workpiece should be paid attention to. In addition, pulse perforation also needs a more reliable gas path control system to realize the switching of gas type and gas pressure and the control of perforation time. More importantly, the temporal and spatial characteristics of the beam, so the general cross flow CO 2 laser can not meet the requirements of laser cutting. Therefore, the laser used should not only have high output power In this way, the perforation diameter is smaller and its perforation quality is better than blasting perforation. Once the perforation is completed, immediately replace the auxiliary gas with oxygen for cutting. The gas pressure is lower than the oxygen pressure during cutting.Įach pulse laser produces only a small particle jet and gradually deepens, so the perforation time of the thick plate takes a few seconds. The pulse laser with peak power is used to melt or vaporize a small amount of materials, and air or nitrogen is used as auxiliary gas to reduce the hole expansion due to exothermic oxidation. In order to make the continuous vibration perforation mode with short time and high-quality hole shape, air can be mixed into the auxiliary gas (oxygen) and the laser moves in a circle.Ģ) Pulse perforation, also known as pulse vibration mode. In order to discharge the molten metal smoothly, the irradiation position of the laser can be moved during perforation. In order to prevent excess combustion, inert gas can be mixed into the auxiliary gas (oxygen). When the continuous vibration mode is selected for perforation, the reason why the hole diameter becomes larger is that high-temperature splashes accumulate around the hole on the upper part of the cutting material, resulting in excess combustion with the auxiliary gas (oxygen). In addition, because the oxygen pressure used for perforation is the same as that during cutting, the splash is large. Therefore, the blasting hole diameter of the thicker plate is large and not round, so it is not suitable to be used on the parts with higher requirements. The average diameter of the blasting hole is half of the plate thickness. Generally, the size of the hole is related to the plate thickness. There are two basic perforation methods for laser cutting machines without stamping devices.ġ) Blasting perforation, also known as continuous vibration mode.Īfter the material is irradiated by continuous laser, a pit is formed in the center, and then the molten material is quickly removed by the oxygen flow coaxial with the laser beam to form a hole. Previously, in the laser stamping compound machine, a hole was punched with a punch, and then cut from the small hole with a laser. In shape cutting, it is usually necessary to open a hole (perforation processing) when entering the cutting from the cutting starting point.

Co2 laser parameters