The Brazing energy chemical reaction heat, indirect heat. It is a melting point lower than the melting point of the welded materials of metal for  Welding Electrodes, after heating the solder melts, the solder materials and rely on capillary action into the gap of the joint contact surface wetting welded metal surface, so that the liquid and interdiffusion between the solid phase and the formation of brazed joints. Therefore, the brazing is one kind of solid phase and liquid phase welding method. Brazing heating temperature is low, the base metal does not melt, but also do not need to exert pressure. Before welding must take certain measures to clear the be welders surface, grease, dust, oxide film. This workpiece wettability to ensure that the important guarantee of the quality of the joint. Liquidus humidity of the solder is higher than 450 ° C lower than the melting point of the base metal, called brazing; lower than 450 ℃, known as soft soldering. Different brazing can be divided according to the heat source or heating methods: Brazing Alloys, induction brazing, furnace brazing, dip brazing, resistance brazing. Brazing due to the relatively low heating temperature, the performance of the workpiece material is smaller, the smaller the stress and deformation of the weldment. But the strength of brazed joints are generally relatively low, the heat capacity is poor. Brazing can be used for welding carbon steel, stainless steel, high temperature alloys, aluminum, copper and other metal materials, can also be connected to dissimilar metal, metal and nonmetal. Suitable for welding by carrying little or at room temperature under the joints, particularly suitable for precision, miniature and complex brazing seam weldment.