Research status and future development of laser welding technology

The application of laser technology in welding manufacturing industry is the focus of research in many countries. With the demand of high efficiency, environmental protection and automation, the application of laser welding technology is rapidly popularizing in many fields of manufacturing industry. On this basis, laser welding technology will become an important aspect of laser application. Laser welding is an important part of the application of laser processing technology. It is also the most attractive and promising welding technology in the 21st century. As early as the end of the last century, European and American countries have fully applied laser welding technology to industrial production. While accelerating the research and development of laser welding technology, China has gradually established a “production, learning, research” development mechanism, and has made great breakthroughs in individual fields. With the development of industrial manufacturing, highly efficient, agile and environment-friendly processing technology will be very popular. Laser welding can realize deep penetration welding, rapid welding and other welding processes with high energy beam focusing mode, which is difficult to realize. Especially, laser welding equipment collocation is flexible, real-time online detection technology is mature, so that it can achieve a high degree of automation in mass production. The welding production line is put into industrial production. Practice has proved that laser welding has a wide range of applications in the processing industry. Basically, laser welding can be competent in the application of traditional welding technology, and the welding quality is better and the processing efficiency is higher. Welding technology with laser technology Laser welding is a process that utilizes the radiation energy of laser to realize effective welding. The principle of laser welding is to excite the laser active medium (such as the mixture of CO2 and other gases, YAG Yttrium aluminum garnet crystal, etc.) to oscillate in the resonator reciprocating, thus forming a stimulated radiation beam, which acts as light. When the beam is in contact with the workpiece, its energy is absorbed by the workpiece and can be welded when the temperature reaches the melting point of the material. 1 laser welding mode Laser welding can be divided into heat conduction welding and deep penetration welding, the former heat transfer to the workpiece internal diffusion, only in the weld surface melting phenomenon, the workpiece internal is not completely penetrated, basically does not produce vaporization phenomenon, mostly used for low-speed thin-walled material welding; the latter not only fully penetrates the material, but also makes the material vapor. A large amount of plasma is formed, and the keyhole phenomenon will appear at the front of the molten pool due to the high heat. Deep penetration welding can thoroughly penetrate the workpiece, and the input energy is large, welding speed is fast, is the most widely used laser welding applications. 2 weld shape and performance of laser welding Because of the small area of focusing spot produced by laser, the heat-affected zone around the weld is much smaller than that of ordinary welding process, and laser welding generally does not need filling metal, so the weld surface is continuous and uniform, beautiful, no pores, cracks and other surface defects, it is very suitable for the weld shape requirements. The occasion of the grid. Although the focus area is relatively small, the energy density of the laser beam is large. In the welding process, the metal is heated and cooled very fast, the temperature gradient around the molten pool is relatively large, so that the joint strength is often higher than the base metal, on the contrary, the joint plasticity is relatively low. At present, the joint quality can be improved by dual focus technology or composite welding technology. 3 advantages and disadvantages of laser welding The reason why laser welding is so highly valued is its unique advantages: (1) High quality joint strength and large aspect ratio can be obtained by laser welding, and the welding speed is faster. (2) Because laser welding does not require vacuum environment, remote control and automatic production can be realized through lens and optical fiber. (3) Laser has a higher power density, has a better welding effect on refractory materials such as titanium and quartz, and can weld different performance materials. Of course, there are also shortcomings in laser welding. (1) The cost of laser and welding system accessories is more expensive, so the initial investment and maintenance costs are higher than the traditional welding process, and the economic benefits are poor. (2) Due to the low absorption of laser by solid materials, especially after the occurrence of plasma, the conversion efficiency of laser welding is generally low (usually 5% ~ 30%). (3) Because the focus spot of laser welding is small, the equipment precision of the workpiece joint is required to be high, and a small deviation of equipment will produce a larger machining error. With the popularization and application of laser welding and the commercialization of laser production, the price of laser equipment has dropped significantly. With the development of high power laser and the development and application of new hybrid welding methods, the low conversion efficiency of laser welding has been improved. It is believed that in the near future, laser welding will gradually replace the traditional welding technology (such as arc welding and resistance welding), and become the main way of industrial welding.铜焊丝,Copper Welding Rods,铝焊丝,aluminium welding wire,镍焊条,Nickel electrode,药皮焊条,Flux Coated Brazing Welding Rods