With the advantages of high efficiency, high precision, good effect and easy automatic integration, laser welding is widely used in various industries, and plays a pivotal role in industrial production and manufacturing, including in the military, medical, aerospace, 3C auto parts, mechanical sheet metal, new energy, bathroom hardware and other industries.
However, if any processing method does not master its principle and process, it will produce certain defects or defective products, and laser welding is no exception. Only a good understanding of these defects, and learn how to avoid these defects, in order to better play the value of laser welding, processing a beautiful appearance, good quality products. Guosheng laser application engineers through long-term experience accumulation, summed up some common welding defects solutions for industry colleagues reference!
1. The cracks
The cracks produced in laser continuous welding are mainly hot cracks, such as crystallization cracks and liquefaction cracks. The main reason is that the weld produces a large shrinkage force before the complete solidification, and measures such as wire filling and preheating can reduce or eliminate cracks.
2. The porosity
Porosity is one of the most common defects in laser welding. The welding pool of laser welding is deep and narrow, and the cooling speed is fast, and the gas generated in the liquid welding pool does not have enough time to escape, which easily leads to the formation of pores. However, laser welding cools quickly, and the porosity generated is generally smaller than that of traditional fusion welding. Cleaning the surface of the workpiece before welding can reduce the tendency of pores, and the direction of blowing will also affect the formation of pores.
3. The splash
The splash produced by laser welding seriously affects the weld surface quality and can contaminate and damage the lens. Spatter is directly related to power density, and appropriate reduction of welding energy can reduce spatter. If the penetration is insufficient, the welding speed can be reduced.
4. The undercut
If the welding speed is too fast, the liquid metal behind the hole pointing to the center of the weld has no time to redistribute, and the solidification on both sides of the weld will form an undercut. Too large a joint assembly gap and the reduced melting metal of the caulk is easy to form undercut. At the end of laser welding, if the energy decline time is too fast, and the small hole is easy to collapse, which results in local undercut. Control power and speed matching can be a good solution to the generation of the undercut.
5. The collapse
If the welding speed is slow, the molten pool is large and wide, the amount of molten metal increases, and the surface tension is difficult to maintain the heavy liquid metal, the weld center will sink, forming collapse and pits. At this time, the energy density should be properly reduced to avoid the collapse of the molten pool.
Correctly understanding the defects generated in the laser welding process and understanding the causes of different defects can be more targeted to solve the problem of abnormal welding seams in laser welding.
Xi'an Guosheng Laser Technology Co., Ltd. is a high-tech enterprise specializing in R&D, manufacturing and sales of automatic laser cladding machine, high-speed laser cladding machine, laser quenching machine, laser welding machine and laser 3D printing equipment. Our products are cost-effective and sold domestically and abroad. If you're interested in our products, please contact us at bob@gshenglaser.com.