For metal welding, according to the characteristics of the process, it can be divided into the following three categories: fusion welding, pressure welding, and brazing. Fusion welding refers to the process of melting a welded joint at high temperatures during the welding process. Due to the tight adhesion of the welded parts, under the action of temperature field, gravity, etc., without pressure, the molten liquid of the two workpieces will mix. After the temperature drops, the melted part condenses, and the two workpieces are firmly welded together, completing the welding method. Pressure welding refers to the process of achieving atomic bonding between two workpieces in a solid state under pressure, also known as solid-state welding. Brazing refers to the use of a metal material with a lower melting point than the workpiece as the brazing material, heating the workpiece and brazing material to a temperature higher than the melting point of the brazing material but lower than the melting point of the workpiece, wetting the workpiece with liquid brazing material, filling the interface gap, and achieving atomic diffusion with the workpiece, thereby achieving welding. Welding technology, with a history of over a hundred years since its invention, has played an important role in the industrialization process. At present, welding technology is still constantly developing.
