High power fibre lasers are suitable for processing steel with an absorption rate of over 50%, but are limited by the fact that highly reflective metallic materials reflect 90% or more of the NIR laser radiation incident on their surface. Especially with near infrared lasers for yellow metals such as copper and gold, the low absorption rate means that a large amount of laser power is required to start the welding process. As metal processing technology continues to advance and user requirements increase, lasers need to innovate in terms of cost and energy efficiency as well as laser system performance. The market need to be able to efficiently process highly reflective metals has inspired the development of blue high-power laser technology and is set to open the door to new technologies in metal processing. The following describes the application of blue light laser welding technology in the welding of highly anti-metallic materials.
Copper absorbs blue light more than 13 times more than infrared light. In addition, the absorption rate does not change much when copper melts and once the blue laser starts welding, the same energy density will allow the welding to continue.Blue laser welding offers inherently good control and fewer defects, the result is fast and high quality copper welds, with a wavelength of 450nm promising nearly 20 times more efficient processing of copper materials than a wavelength of 1μm.The high power blue laser offers quantitative and qualitative advantages over conventional near infrared laser welding processes.
Highly reflective metals such as copper and gold absorb 7 to 20 times more of the blue light spectrum than infra-red, and the solution lies in using light of shorter wavelengths in the blue light category for the industrial processing of non-ferrous metals.Firstly, blue light has its own specific properties. The high absorption of blue light by highly reflective metallic materials means that blue light has a huge advantage for metal processing of highly reflective materials (e.g. copper).Secondly, the absorption rate does not change much as the copper melts. Once the blue laser starts welding, the same energy density will allow the welding to continue.Finally, blue laser welding has inherently good control and few defects, the result being fast and high quality copper welds.
Typical current applications of the blue light oscillating compound welding technology are battery adapter welding.The welding of the adapter is an extremely important process in the production process of the power cell, playing a role in connecting the cover and the cell, the quality of the welding seam directly affects the performance of the entire cell.The weld needs to have a certain area in order to guarantee the overcurrent capacity, so a certain width of the weld joint is required.Welding must not leave residual spatter to avoid internal short-circuiting of the battery caused by the particle, which affects the safety performance of the battery.Welding must not leave residual spatter to avoid internal short-circuiting of the battery caused by the particle, which affects the safety performance of the battery.
Overall, the increased welding speed of the blue laser translates directly into faster productivity, as well as minimising production downtime.Consistency in weld quality results in a significant increase in production yields; the unique advantages of high quality welds without spatter and porosity, as well as higher mechanical strength and lower resistivity broaden the process range.In addition, the blue laser can also perform thermally conductive welding patterns, which are not possible with near-infrared lasers.As a modern advanced processing technology, blue light oscillating composite welding technology creatively solves the problem of laser processing in many industries, greatly improving the quality of products for downstream customers, and will certainly be widely used in many fields such as new energy batteries, consumer electronics, motors, motors and transformers, generating significant economic and social benefits.
