The essence of fusion welding is the melting and crystallization of metal, similar to the small casting process;

The essence of pressure welding is through the plastic deformation of the metal welding parts, crush or squeeze out the oxides and other impurities of the joint surface, so that the pure metal is in close contact, the atomic spacing between the interface reaches the normal stress range and the firm combination;

The essence of brazing is to use liquid solder to wetting the base metal, filling the joint gap, and mutual diffusion with the base metal to connect the weldment

Brazing is connected by a third metal, not a true welding.Fusion welding is a process by which heat is used to make a connection.

Fusion welding: Process in which the parts to be soldered are locally heated until they are melted and condensed to form a weld so that the components are joined together.Including arc welding, gas welding, electroslag welding, electron beam welding, laser brazing;

Brazing The joint action of wetting of filler metal and capillary penetration makes the material combine, heating the filler metal with a lower melting point than the base metal until it melts, but the heating temperature is lower than the melting point of the base metal, filling the weld with the melted filler metal, wetting the base metal and diffusing with the base metal to form a whole welding method.

Brazing can be divided into two categories: hard brazing and soft brazing.The heating temperature of hard brazing is greater than 450 degrees, and the tensile strength is greater than 200 MPa. It is often used with silver base and copper base solder. It is suitable for the occasions of high working stress and high ambient temperature, such as the welding of carbide turning tool and geological drill bit.The heating temperature of soft brazing is less than 450 degrees and the tensile strength is less than 70 MPa. It is suitable for the environment with small stress and low working temperature.Such as circuit tin - based brazing light welding, etc.

In the brazing process, the metal material with lower melting point than the base metal is used as the filler metal, and the welding parts and the filler metal are heated to a temperature higher than the melting point of the filler metal and lower than the melting point of the base metal.