Laser welding is a significant aspect of laser material processing technology. It can be categorized based on its working method into laser mode welders (manual welders), automatic laser welders, laser spot welders, and fiber-optic transmission laser welders. Laser welding involves using high-energy laser pulses to locally heat small areas of the material, with the energy of the laser radiation diffusing into the material through heat conduction, causing it to melt and form a specific molten pool, thereby achieving the welding objective.
The principle of laser welding machines is essentially to complete welding through pulse laser beams. It can be divided into thermal conduction and laser deep penetration. The thermal conduction principle involves heating the area to be welded through radiation. As surface heat gradually penetrates into the material interior through conduction, melting the workpiece can be achieved by relative energy, repetition frequency, and relevant laser parameters. Laser deep penetration requires a continuous laser beam to perform the task, thereby achieving inter-material connection and welding depth. With technological advancement (categorized as pulse laser welding and continuous laser welding), pulse laser welding has less than or equal to 100 spots per second, while continuous laser welding can reach less than or equal to 5,000 spots per second. This welding principle, under sufficient high-density laser exposure, allows the welding material to rapidly absorb the energy of the laser beam at a point, resulting in complete melting and penetration of the metal.
Compared to other traditional welding techniques, the main advantages of laser welding are:
1. The laser beam's focal spot is small with high power density, capable of welding high melting point and high-strength alloy materials.
2. Laser welding is a contactless processing method, without tool wear or tool change issues. The laser beam energy is adjustable, as is the movement speed, allowing for various types of welding processes.
3. Laser welding boasts high automation, can be controlled by computer, offers rapid welding speeds, and high efficiency, allowing for convenient welding of any complex shapes.
4. Laser welding has a small heat-affected zone, resulting in minimal material deformation, and no further processing is required.
5. Lasers can weld workpieces inside vacuum containers and those located in the interior of complex structures.
6. Laser beams are easy to direct and focus, allowing for transformations in all directions.
7. Laser welding compares favorably to electron beam processing, as it does not require a stringent vacuum equipment system and is easy to operate.
8. Laser welding offers high production efficiency, stable and reliable processing quality, and good economic and social benefits.
Application:
Laser welding technology is suitable for welding metals such as gold, silver, titanium, nickel, tin, copper, aluminum, stainless steel, galvanized steel, and their alloys. It enables precise welding between the same type of metal and different types of metals, and has been widely used in industries such as aerospace equipment, shipbuilding, instruments and meters, electromechanical products, hardware accessories, kitchenware, digital accessories, fitness equipment, precision machinery, and automotive manufacturing.
