Laser welding machine uses high-energy laser pulses to locally heat the material in a small area. The energy of the laser radiation diffuses into the material through heat conduction, and the material is melted to form a specific molten pool. It is a new type of welding method, mainly for the welding of thin-walled materials and precision parts, and can realize spot welding, butt welding, stitch welding, sealing welding, etc. Laser welding machines are widely used in various industries with the advantages of high efficiency, good effect, high precision, and easy automation integration. At present, it has been fully utilized in aerospace, health care, 3C digital, auto parts, mechanical meal gold, new energy, bathroom hardware and other industries. So when using a laser welding machine, what factors will affect the welding quality of the laser welding machine?
1. Laser Waveform
In the welding process, the laser waveform is an important factor affecting the quality of laser welding. When the high-intensity laser is incident on the data surface, the metal surface will reflect 60%~98% of the laser energy, and the reflectivity will change with the surface temperature. Therefore, the laser reflectivity and laser utilization rate of different metals are different. For effective welding, lasers with different waveforms must be input, so that the metal arrangement at the weld is crystallized in the best way to form a co-alignment with the base metal to form a high-quality weld.
2. Laser Spot Gathering Diameter
The laser spot gathering diameter is an extremely important parameter reflecting the planning function of the laser, which determines the power density and processing scale of the laser. If the optical planning of the laser is reasonable and advanced, the laser energy will be collected and concentrated accurately, and the diameter of the laser spot can be controlled in the range of 0.2-2mm. Whether the diameter of the laser gathering can be controlled within 0.2mm is a severe test for the laser generator.
3. Laser Frequency
Laser welding machines use the energy of a laser to weld metals. In the case of constant laser power, the higher the frequency, the smaller the output energy of each laser. Therefore, we need to consider the processing speed and determine the output frequency of the laser under the condition that the laser energy is sufficient to melt the metal. Too high frequency will inevitably lead to too low laser energy, which will constitute welding failure.
In order to ensure the welding quality, such as the reliability and stability of weld formation, in the high-speed continuous laser welding process, the following methods need to be taken. On the one hand, it is necessary to use a laser with good beam quality and laser output power stability, and use high-quality, high-stability optical components to form its light guide focusing system, and to maintain it frequently to prevent pollution and keep it clean. On the other hand, it is necessary to ensure the machining accuracy and assembly accuracy of the workpiece, and set different laser processing parameters for different processing materials, and select the appropriate laser power, welding speed, laser waveform, defocus amount and shielding gas. Optimize processing parameters according to different welding effects to improve the reliability and stability of laser welding quality.