1.laser weldingLaser welding: laser radiation to be processed surface, the surface heat through the heat conduction to the internal diffusion, by controlling the laser pulse width, energy, peak power and repetition frequency and other laser parameters, so that the workpiece melting, the formation of a specific pool.Laser welding can be used to achieve continuous or pulsed laser beam, the principle of laser welding can be divided into heat conduction welding and laser deep welding. Power density of less than 10 ~ 10 W / cm for the heat conduction welding, this time the depth of penetration, welding speed is slow; power density greater than 10 ~ 10W / cm, the metal surface under the heat of the concave into a “hole” to form a deep welding, Welding speed, depth ratio of large features.Laser welding technology is widely transported in the automotive, ship, aircraft, high-speed rail and other high-precision manufacturing areas, to people’s quality of life has brought a significant upgrade, it is to lead the home appliance industry into the Seiko era.Especially in the Volkswagen to create 42 meters seamless welding technology, greatly improving the overall body and stability, the appliance leading enterprises Haier Group launched a grand laser welding technology used in the production of washing machines, advanced laser technology can be The people’s lives have brought great changes.2.laser composite weldingLaser composite welding is a combination of laser beam welding and MIG welding technology to obtain the best welding effect, fast and weld bypass capability, is the most advanced welding methods.The advantages of laser composite welding are: fast, small thermal deformation, small heat affected area, and to ensure that the weld metal structure and mechanical properties.Laser composite welding in addition to automotive sheet structure welding, but also for many other applications. Such as the application of this technology to the production of concrete pumps and mobile crane girders, which require high strength steels to be processed, and conventional techniques tend to result in increased costs due to the need for other ancillary processes such as preheating. Furthermore, the technology can also be applied to the manufacture of rail vehicles and conventional steel structures (such as bridges, fuel tanks, etc.).3.friction stir weldingFriction stir welding is the use of friction heat and plastic deformation heat as a welding heat source. The friction stir welding process is carried out by means of a cylinder or other shape (such as a threaded cylinder) into the joint of the workpiece, through the high-speed rotation of the welding head to make it with the welding workpiece material friction, so that the connection The material temperature is softened.Stirring Friction Welding In the welding process, the workpiece must be rigidly fixed on the back pad, the welding head is rotated at high speed, and the joint of the workpiece along the workpiece moves relative to the workpiece.The protruding section of the welding head extends into the interior of the material for friction and stirring. The shoulder of the welding head is rubbed against the surface of the workpiece and used to prevent the overflow of the plastic state material, and it can also remove the surface oxide film.Stirring the friction at the end of the weld leaving a keyhole at the end. Usually the keyhole can be cut off, you can also use other welding methods sealed to live.Friction stir welding can achieve dissimilar material welding, such as metal, ceramics, plastics and so on. Friction stir welding welding high quality, easy to produce defects, easy to achieve mechanization, automation, quality and low cost efficiency.4. electron beam weldingElectron beam welding is the use of accelerated and focused electron beam bombardment in a vacuum or non-vacuum welding of the heat generated by the welding method.Electron beam welding is widely used in many industries such as aerospace, atomic energy, national defense and military, automobile and electrical and electrical instrumentation because of its advantages such as no welding rod, easy oxidation, good process reproducibility and small thermal deformation.Electron beam welding working principleElectrons from the electron gun in the emitter (cathode) to escape, under the action of accelerating voltage, the electron is accelerated to the speed of light 0.3 to 0.7 times, with a certain kinetic energy. And then by the electron gun in the role of electrostatic lens and electromagnetic lens, convergence success rate of high density of electron beam flow. This electron beam impinges on the surface of the workpiece, and the kinetic energy of electrons changes into heat to melt and evaporate the metal quickly. In the high-pressure metal vapor, the workpiece surface is quickly “drill” out of a small hole, also known as “keyhole”, with the relative movement of the electron beam and the workpiece, liquid metal flows around the hole along the hole, And cooled to form a weld.Main features of electron beam weldingElectron beam penetrating ability, high power density, weld aspect ratio, up to 50: 1, can achieve a large thickness of a material forming, the maximum welding thickness of 300mm. Welding accessibility, welding speed, generally more than 1m / min, heat affected zone is small, welding deformation is small, high precision welding structure. Electron beam energy can be adjusted, the thickness of the metal can be welded from thin to 0.05mm to thick to 300mm, do not open the groove, a welding forming, which is other welding methods can not be achieved. The range of materials that can be used for electron beam welding is large, especially for reactive metal, refractory metals and high quality workpiece welding.5.Ultrasonic metal weldingUltrasonic metal welding is the use of ultrasonic frequency of mechanical vibration energy, connected to the same kind of metal or a special method of dissimilar metals. Metal in the ultrasonic welding, neither to the workpiece to send current, nor to the workpiece to the high temperature heat source, but under the static pressure, the frame vibration energy into the work of the friction work, deformation energy and limited temperature rise. The metallurgical bonding between the joints is a solid state welding where the base material does not melt.It effectively overcome the resistance welding generated by the splash and oxidation and other phenomena, ultrasonic metal welding machine can copper, silver, aluminum, nickel and other non-ferrous metal filament or sheet material for single-point welding, multi-point welding and short Shaped welding. Can be widely used in SCR wire, fuse chip, electrical leads, lithium battery pole pieces, the ear of the welding.Ultrasonic metal welding using high-frequency vibration wave to be welded to the metal surface, in the case of pressure, so that the two metal surfaces friction between the formation of molecular layer between the fusion.Ultrasonic metal welding is characterized by fast, energy saving, high fusion strength, good conductivity, no spark, close to cold processing; the disadvantage is that the welding metal parts can not be too thick (generally less than or equal to 5mm), the solder bit can not be too large, need Pressurized.6. flash butt weldingThe principle of flash butt welding is to use the welding machine to make both ends of the metal contact, through the low voltage of the high current, until the metal is heated to a certain temperature softening, the axial pressure upset forthe formation of butt welding joints.Two weldments are not touched by the two clamp electrode clamped and connected to the power supply, move the movable fixture, the two pieces of the end of the light contact that is heated, the contact point due to heating the formation of liquid metal blasting, jet sparks flash, Continuous moving movable fixture, continuous flash, welding pieces at both ends of the heating, to a certain temperature, the extrusion of the workpiece side, cut off the welding power, firmly welded together. The use of resistance heating welding joints to make the contact point flash, melting the weld end of the metal, the rapid application of the top force to complete the welding.Reinforcing steel flash butt welding is the installation of two bars into a docking form, the use of welding current through the two steel contact point generated by the heat resistance, the contact point of metal melting, resulting in a strong splash, the formation of flash, accompanied by irritating odor, the release of trace Molecules, the rapid application of the forging force to complete a welding method.
Source: Meeyou Carbide

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