The application of laser technology in manufacturing has become a focal point of research across countries. With the industrial development's demand for environmental protection and automation, the application of laser technology has rapidly expanded into many manufacturing fields. On this basis, laser welding technology will become one of the important aspects of laser applications. Laser welding is a significant component of laser processing technology and is a noteworthy, promising welding technique in the 21st century.
Aluminum Alloy Laser Welding Distortion
Aluminum alloys have a high linear expansion coefficient and are prone to welding deformation. Laser welding of aluminum alloys results in relatively minor deformation, yet even in high-precision welding of IT components, even slight deformations can have a significant impact, necessitating preventive control. Typically, the heat input of traditional continuous laser welders used for seam welding is greater than that of pulsed laser spot welding, leading to greater deformation. Fiber laser systems have smaller beam diameters, more concentrated energy, and can weld at higher speeds with less heat input, thus resulting in less distortion compared to traditional continuous lasers.
Due to the aforementioned characteristics of fiber laser, the strength of the fiber laser welding of aluminum alloy IT components is significantly higher than that of pulsed lasers. By optimally adjusting the welding parameters of the fiber laser, the number of welds, the length of the welds, and their distribution, the workpieces meet the requirements. Simultaneously, the strength requirements are reduced, and the total heat input during the welding process is minimized, further reducing the thermal deformation of the workpieces. Measurement shows that the overall welding deformation of the fiber laser welds exceeds that of pulsed laser spot welding by over 3.5%, with the pulse laser spot welding process showing minimal variation, which meets practical requirements.
Aluminum alloy laser welding can significantly reduce the strength of the weld joint, greatly impacting the practicality and reliability of the product, making it one of the dangerous welding defects. During pulse laser spot welding of aluminum alloys, cracks are a major factor affecting welding strength. Due to the inevitability and irregularity of cracks, the spot welding strength of aluminum alloys is far below the material's inherent strength, resulting in a large strength discrepancy between the welded products and the material itself, with poor stability. Continuously welding a fiber laser to aluminum alloys can prevent the occurrence of weld cracks, effectively enhancing the strength and stability of the weld.
