An Overview of Laser Beam Welding

摘要

Laser beam welding (LBW) is a welding process that uses a laser to join metal or thermoplastic parts. The beam acts as a focused heat source, enabling for thin, deep welds and fast welding speeds. The procedure is commonly employed in high-volume, automated applications, such as the automotive sector. Welding in the keyhole or penetration mode is used. Laser beam welding, like electronbeam welding (EBW), has a high power density (on the order of 1 MW/cm2), which results in small heat-affected zones and rapid heating and cooling. The laser's spot size can range from 0.2 mm to 13 mm, however only lower sizes are employed for welding. The depth of penetration is related to the amount of power delivered, but it also depends on the placement of the focal point: when the focal point is just below the workpiece's surface, penetration is maximum. Depending on the purpose, a continuous or pulsed laser beam may be utilised. Welding thin materials like razor blades is done with millisecond-long pulses, while deep welds are done using continuous laser systems. Carbon steels, HSLA steels, stainless steel, aluminium, and titanium can all be welded using the LBW technique. When welding high-carbon steels, cracking is a risk due to high cooling rates. The weld quality is excellent, comparable to electron beam welding. Welding speed is related to the amount of power applied, but it is also affected by the type and thickness of the workpieces. Gas lasers are ideal for high-volume applications because to their high power capability. LBW has a stronghold in the automobile industry.