Brazing between soft brazing and hard brazing

Brazing is a welding method that achieves the connection of metal or non-metal materials by melting a low-melting-point metal (solder) to fill the gap between the joints.

Application: Carbide cutting tools, drilling bits, bicycle frames, heat exchangers, conduits and various containers, etc.; in the manufacturing of microwave waveguides, electron tubes and electronic vacuum devices, brazing is even the only possible connection method.

Soft brazing

Soldering where the melting point of the solder is lower than 450°C is called soft soldering. The commonly used solder is tin-lead solder. It has good wettability and conductivity and is widely used in electronic products, electrical appliances and auto parts. The joint strength of soft soldering is generally 60~140MPa.

Hard brazing

Brazing with a solder melting point higher than 450°C is called brazing. Commonly used solders are brass solder and silver-based solder. Joints using silver-based solder have high strength, conductivity and corrosion resistance. The melting point of the solder is low and the processability is good. However, the price of the solder is high. It is mostly used for welding parts with higher requirements. Generally, there are many welding parts. Use brass solder. Brazing is mostly used for brazing steel and copper alloy workpieces that are subject to greater stress, as well as tools. The joint strength of brazing is 200~490MPa.

Common Brazing heating method

(1) Flame brazing: Heating with gas flame, used for brazing carbon steel, stainless steel, cemented carbide, cast iron, copper and copper alloys, aluminum and aluminum alloys.

(2) Induction brazing: Resistance heating welding parts that use an alternating magnetic field to generate induced current in parts. It is used for welding parts with symmetrical shapes, especially for brazing of pipe shafts.

(3) Brazing in the furnace: The resistance furnace is used to heat the weldment. The resistance furnace can protect the weldment by vacuuming or using reducing gas or inert gas.

Brazing can be used to weld carbon steel, stainless steel,high-temperature alloys, aluminum, copper and other metal materials, and can also connect dissimilar metals, metals and non-metals. It is suitable for welding joints with low load capacity or working at normal temperature. It is especially suitable for precision, micro and complex multi-brazing welding parts.