Introduction of Wire Beam Welding Process

Wire beam welding methods include diffusion welding, high-frequency welding, cold welding, and ultrasonic welding.
1, diffusion welding
The welding parts are closely fitted and kept under a certain temperature and pressure for a period of time, so that the atoms between the contact surfaces diffuse to form a joint welding method. The main factors affecting the diffusion welding process and joint quality are temperature pressure diffusion time and surface roughness. The higher the welding temperature, the faster the atomic diffusion, the welding temperature is generally 0.5 to 0.8 times the melting point of the material. According to the type of material and the requirements for the quality of the joints, diffusion welding can be carried out in vacuum, protective gas or solvent, of which vacuum diffusion welding is the most widely used. In order to speed up the welding process, reduce the requirements for welding surface roughness, or prevent harmful tissues from appearing in the joints, an intermediate sandwich material with a specific component is often added to the welded surface, and its thickness is about 0.01 mm. The diffusion welding pressure is small, the workpiece does not produce macroscopic plastic deformation, and it is suitable for precision parts that are no longer processed after welding. Diffusion welding can be combined with other heat processing processes to form a combination of processes such as heat consumption-diffusion welding, powder sintering-diffusion welding and ultra-plastic forming-diffusion welding. These combined processes not only greatly increase productivity, but also solve problems that can not be solved by individual processes. For example, various titanium alloy components on supersonic aircraft are diffusion welding joints made of ultra-plastic forming and diffusion welding. The performance of the joints can be the same as that of the base metal. It is especially suitable for welding non-metallic materials such as heterogeneous metal materials, graphite and ceramics, diffuse reinforced high-temperature alloys, metal-matrix composites, and porous sintering materials. Diffusion welding has been widely used in the manufacture of reactor fuel elements, Honeycomb structure plates, electrostatic acceleration tubes, various blades, impellers, punching molds, filtration tubes and electronic components.
Diffusion welding is the physical contact between the welded surfaces of the soldered substances under a certain temperature and pressure, and the physical contact of the soldered surfaces is expanded through microscopic plastic deformation or the production of trace liquid phases through the soldered surfaces. Make it within(1 ~ 5) x10-8cm(so that the gravitational pull between atoms can form metal bonds), and then through the continuous diffusion and mutual penetration of atoms for a longer period of time, A welding method to achieve metallurgical binding.
Obviously, for ordinary wire beam welding, the cost of using diffusion welding is too high.
2, high frequency welding(high frequency welding)
High-frequency welding is based on solid resistance heat. During welding, the resistance heat generated by high-frequency currents in the workpiece heats the surface of the workpiece welding area to a molten or near-plastic state, and then exerts(or does not apply) top forging force to achieve metal binding. Therefore, it is a fixed phase resistance welding method. High frequency welding can be divided into contact high frequency welding and induction high frequency welding according to the high frequency current generating heat in the workpiece. When exposed to high frequency welding, high frequency current is transmitted to the workpiece through mechanical contact with the workpiece. During induction high frequency welding, high frequency current is generated in the workpiece through the coupling of the external induction ring of the workpiece. High frequency welding is a highly specialized welding method, according to the product equipped with special equipment. High productivity, welding speed up to 30m/min. It is mainly used for welding longitudinal seams or spiral seams when making tubes.
Obviously, high frequency welding is not suitable for small wire bundles.
3, cold welding
Cold welding, English for cold press welding
During the pressure deformation, the oxide film of the contact surface of the workpiece is destroyed and extruded, which can purify the welded joint. The added pressure is generally higher than the yield strength of the material to produce 60 to 90 % of the deformation. The pressure method can slowly squeeze, roll, or add impact, or it can be applied several times to achieve the required deformation.
Cold pressure welding equipment is simple because it does not require heating and packing. The main process parameters of welding have been determined by the mold size, so it is easy to operate and automate, the welding quality is stable, the productivity is high, and the cost is low; Without solder, the joint will not cause corrosion; The joint temperature does not rise during welding, and the crystal state of the material remains unchanged. It is particularly suitable for welding some metal materials and products that can not be achieved by heterogeneous metal and thermal welding. Cold pressure welding has become one of the most important and limited welding methods in the electrical industry, aluminum products industry and space welding field.
The working surface of the cold press welding machine and its molds may accumulate metal debris and must be cleaned regularly. If there is compressed air, use compressed air to blow away the debris. If you want to thoroughly remove debris, remove the mold from the welder, take the four modules of the mold apart, and use a magnifying glass to carefully examine each module to ensure that the trace debris on the surface of all modules is removed. Be careful when demoulding, especially when the small spring is easily lost. The surface of the mold is not clean will cause the wiring line will be easy to slip in the mold, so that the welding failed. Note that no grease is allowed on the working surface of the repaired mould.
The equipment required for cold pressure welding is simple, the process is simple, and the working conditions are good. However, the extrusion pressure required for cold pressure welding is large, and the equipment is larger when the large-section workpiece is welded. After the welding, the workpiece surface has a deeper pressure pit, which limits its application scope to a certain extent.
Therefore, cold pressure welding is not a perfect choice for wire beam welding.