Laser welding is a significant aspect of laser material processing technology. It can be categorized into laser seam welders (manual welders), automatic laser welders, laser spot welders, and fiber-optic transmission laser welders. The process involves using high-energy laser pulses to locally heat a small area of the material, with the energy from 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 pulsed laser beams. Its principle can be divided into thermal conduction and laser deep penetration. The thermal conduction principle refers to the pointer heating the area to be welded through radiation. As the surface heat gradually penetrates into the material interior through thermal conduction, the workpiece can be melted through relative energy, repetition frequency, and relevant laser parameters. Laser deep penetration requires a continuous laser beam to perform the task, thereby achieving material interconnection and welding depth. With technological upgrades (divided into pulsed laser welding and continuous laser welding), pulsed 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 radiation, 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, eliminating tool wear and tool change issues. The laser beam energy and movement speed are adjustable, allowing for various welding processes.
3. Laser welding offers high automation, controllable by computer, with rapid welding speed and high efficiency, allowing for convenient welding of any complex shapes.
4. Laser welding has a small heat-affected zone and minimal material deformation, eliminating the need for subsequent processing.
5. Lasers can weld workpieces inside vacuum chambers and within intricate structural interiors.
6. Laser beams are easy to guide and focus, enabling transformations 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:
The laser welding process is suitable for welding metals and alloys such as gold, silver, titanium, nickel, tin, copper, aluminum, stainless steel, and galvanized steel sheets. It allows for precise welding between the same type and different types of metals, and has been widely used in industries such as aerospace equipment, shipbuilding, instruments and meters, electromechanical products, hardware decorations, kitchenware, digital accessories, fitness equipment, precision machinery, and automotive manufacturing.
