Laser welding is an important aspect of laser material processing technology. It can be categorized according to its working mode into laser mode welders (manual welders), automatic laser welders, laser spot welders, and fiber-optic transmission laser welders. The process of welding involves using high-energy laser pulses to heat a small area of the material locally, with the energy of the laser radiation being transferred and diffused into the material through thermal 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's interior through conduction, melting the workpiece can be achieved with relative energy, repetition frequency, and relevant laser parameters. Laser deep penetration requires a continuous laser beam to perform the task, thereby connecting and welding materials at a depth. With technological advancements (categorized into pulse and continuous laser welding), pulse laser welding has fewer than or equal to 100 spots per second, while continuous laser welding can reach fewer than or equal to 5,000 spots per second. This welding principle, under sufficient high-density laser irradiation, 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 has a small focal spot with high power density, enabling welding of high melting point and high-strength alloy materials.
2. Laser welding is a non-contact process, eliminating tool wear and tool change issues. The laser beam energy and movement speed are adjustable, allowing for various types of welding operations.
3. Laser welding offers high automation, can be controlled by computer, boasts fast welding speeds and high efficiency, and allows for easy welding of any complex shapes.
4. Laser welding has a small heat-affected zone, resulting in minimal material deformation, eliminating the need for further processing.
5. Lasers can weld workpieces inside vacuum chambers and within the intricate interiors of complex structures.
6. Laser beams are easy to guide and focus, enabling transformation in all directions.
7. Laser welding is more convenient to operate compared to electron beam processing, as it does not require a strict vacuum equipment system.
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 joining metals such as gold, silver, titanium, nickel, tin, copper, aluminum, stainless steel, galvanized steel, and their alloys. It allows for precise welding between the same type of metal and different types, and is widely used in industries such as aerospace equipment, shipbuilding, instruments and meters, electrical and mechanical products, hardware accessories, kitchenware, digital accessories, fitness equipment, precision machinery, and automotive manufacturing.
