Because aluminum light weight, high strength, good corrosion resistance, non-magnetic, good formability and good low temperature performance characteristics have been widely used in a variety of products in welded structures, made of aluminum alloy instead of steel materials welding, structural weight reduce by more than 50%. Currently in the aviation, aerospace, automotive, battery, machinery manufacturing, shipbuilding, chemical industry and daily necessities and other industries widely used.
Advanced aluminum welding technology: laser welding
Aluminum laser welding technology is developed in the last decade a new technology, compared with traditional welding process, it has a strong function, high reliability, no vacuum and high efficiency. Its power density, low total heat input, the same amount of heat input deep penetration, small heat-affected zone, welding deformation small, high speed, easy to industrial automation, etc., especially for heat treatment of aluminum alloy have greater application advantages. Improve the processing speed can be greatly reduced, and heat input, which can improve production efficiency, improve the welding quality. When welding of high strength aluminum alloy thickness, traditional welding methods is impossible to single channel penetration, and the formation of a large depth keyhole laser deep penetration welding, keyhole effect occurs, it can be achieved.
Laser welding of aluminum alloy has the following advantages:
① high energy density, low heat input, heat small amount of deformation, melting zone and heat affected zone is narrow and deep penetration;
② high cooling rate to obtain a fine weld good joint performance;
③ Compared with resistance welding, laser welding without electrode, thus reducing the time and cost;
④ electron beam welding is not required when a vacuum atmosphere, and the protective gas pressure and optionally, is not the shape of welders electromagnetic effects, does not produce X-rays;
⑤ transparent objects inside a sealed can of welding metallic materials;
⑥ laser optical fiber transmission distance available, so that the process adaptability, with computers and robots, can be automated and precise control of the welding process.
Aluminum laser welding laser contrast common
Lasers are now applied mainly CO2 lasers, YAG lasers, fiber lasers.
CO2 laser power, the requirements for high-power thick plate welding is more suitable. But aluminum alloy for CO2 laser beam absorption rate is relatively small, resulting in a large amount of energy loss during the welding process.
YAG laser power is generally relatively small, aluminum surface of YAG laser beam absorption rate is relatively large CO2 laser, the optical fiber transmission available, adaptable, technology arrangement and simple, but YAG output power and low power photovoltaic conversion.
Fiber lasers have a small size, low operating costs, long life, good stability, beam quality advantages. Meanwhile, the 1070 nm wavelength of light emitted from the fiber laser, the absorption rate is higher, photoelectric conversion rate is 10 times that of the YAG laser welding speed faster than the YAG and CO2 lasers.
Welding technology revolution - aluminum welding, high-power laser welding equipment is the trend
Laser welding as a high energy density welding process, welding aluminum can effectively prevent the defects of the traditional welding process produces, strength coefficient increased greatly. Low-power laser welding equipment, aluminum alloy plate welding difficult, while aluminum surface of the laser beam absorption rate is very low, and to reach a threshold exists deep penetration problems, so there is a certain degree of difficulty on the process.
Aluminum laser welding machine the most interesting feature is its high efficiency, and to give full play to such high efficiency make it apply to large thickness of deep penetration welding. High power laser penetration welding of large thickness will be the inevitable trend of future development. Thick deep penetration holes more prominent phenomenon and its impact on the pore in the weld, so the hole formation mechanism and control becomes even more important, it will become the future of welding technology revolution.