Introduction To Welding Technology

• Resistance welding is a welding method that uses resistance heat to heat the workpiece and apply pressure to form a metal bond. In the grouping process of power batteries, resistance welding is a relatively mature technique commonly used for welding between connecting pieces and battery pole pieces. The surface cleanliness of the workpiece is crucial to the welding quality during resistance welding. Therefore, before welding, it is necessary to clean the contact surface between the electrode and the workpiece, as well as between the workpieces. In the early stages of development in the power battery industry, resistance welding was widely used due to its simple equipment and low cost.

 

• Laser welding is a welding method that uses a high-energy density laser beam as a heat source. It should be noted that laser welding is a melting process, which means that during the welding process, both substrates will be melted. When welding different materials, fragile high resistance intermetallic compounds may form. These compounds have been proven to have negative effects on the short-term electrical and long-term mechanical properties of the joints in microelectronic devices.

 

 

• Polymer diffusion welding is a technology developed on the basis of diffusion welding. The principle is that under certain temperature and pressure, the surfaces to be welded come into contact with each other and expand the physical contact of the connected surfaces through microscopic plastic deformation or transient liquid phase formation. Then, a welding method that forms metallurgical bonding through long-term atomic diffusion and permeation.

 

Of course, the disadvantages of polymer diffusion welding are also obvious:

* The preparation and assembly quality of the welded surface require high standards, especially for the joint surface.

* Welding has a long thermal cycle time and low productivity. Each welding process can take a few minutes at a fast pace or several tens of hours at a slow pace. Some metals can cause grain growth.

* The size of the welded workpiece is limited by the equipment and cannot be continuously mass-produced.

 

• Electromagnetic pulse welding is a unique solid-state welding technique that can be completed without the need for heating and cooling processes. It is suitable for connecting dissimilar metals with similar or dissimilar performance, especially for connecting metals with significant differences in crystal structure and performance. Traditional welding has certain requirements for the surface cleanliness of welded parts and welding equipment. And electromagnetic pulse welding technology achieves welding through high-speed collision, which can strip and remove surface impurities before welding, thereby reducing processes and lowering costs.