Analysis of the application history of laser welding in the automotive field

The world's first laser was born in 1960, and my country developed the first laser in 1961. For more than 40 years, laser technology and applications have developed rapidly and have been combined with multiple disciplines to form multiple application technology fields. In the 1980s, laser technology was used in the automotive field, mainly using laser welding of car bodies.　　So, what is laser technology? The laser technology uses a polarizer to reflect the beam generated by the laser to concentrate it in the focusing device to produce a beam of huge energy. If the focus is close to the workpiece, the work piece will melt and evaporate within a few milliseconds. This effect can be used in the welding process. The key to laser welding equipment is high-power lasers, which are mainly divided into two categories. One is solid-state lasers, also known as Nd:YAG lasers. Nd (neodymium) is a rare earth element, YAG stands for yttrium aluminum garnet, and its crystal structure is similar to ruby. The wavelength of Nd:YAG laser is 1.06u0026mu;m. The main advantage is that the generated beam can be transmitted through optical fiber, so complicated beam transmission system can be omitted. It is suitable for flexible manufacturing system or remote processing, and is usually used for welding precision requirements. Artifact. Nd:YAG lasers with output power of 3-4 kW are commonly used in the automotive industry. The other type is gas laser, also known as CO2 laser. Molecular gas is used as the working medium to produce infrared laser with an average of 10.6μm. It can work continuously and output very high power. The standard laser power is between 2-5 kilowatts.　　 Understand what laser technology is, then how is laser technology applied to the automotive field? Especially the application of laser welding technology in the automotive industry. At present, body welding mainly includes resistance electric welding, seam welding, carbon dioxide welding and other methods. Resistance electric welding melts the contact surfaces of the parts by applying current to the spot welding electrodes, and then connects them together under pressure. It is mainly used for welding body parts and frame. Seam welding uses a roller electrode instead of a spot welding electrode for resistance electric welding. The roller electrode transmits welding current and pressure, and its rotation is coordinated with the movement of the part to produce a continuous weld. It is mainly used for sealing welding or seam spot welding of workpieces, such as fuel tanks. . Carbon dioxide welding is a kind of arc welding, that is, a welding method in which local heating is used to melt and connect parts without applying pressure. The arc between the electrode and the workpiece is used as a heat source, and carbon dioxide is applied to cover the arc and the melting zone at the same time. Separated from the atmosphere, it is mainly used for welding of car body skins. (The above is edited and compiled by the metal laser cutting machine from the Internet, please indicate the source for online reprinting!)