Silver-based Brazing Solder

The silver-based solder is usually an alloy mainly composed of silver or a silver-based solid solution. This kind of brazing filler metal has excellent process performance, low melting point, good wetting property and caulking performance, excellent strength, plasticity, electrical conductivity and corrosion resistance. It can be used for brazing except aluminum, magnesium and other low melting point metals. Almost all ferrous and non-ferrous metals are widely used.

There are many types of silver-based solders, but the commonly used silver-based solders contain almost all copper. In order to lower the melting point and reduce the silver content, alloying elements such as zinc, nickel, and cadmium are usually added to form a ternary or multi-component alloy.

B-Ag72Cu is the most widely used eutectic solder in electric vacuum devices. It has a low melting point, no temperature separation during crystallization, good brazing process performance, and good wettability and fluidity on copper and nickel. The conductivity is also very good. However, the brazing material has high brittleness, low strength, and extremely poor wettability to stainless steel, alloy steel, and high-temperature alloy. Therefore, brazing such workpieces should be previously plated with copper or nickel on the surface to be brazed to improve the wetting and spreading properties of the solder. This solder can also be used for pre-soldering of titanium and titanium alloys.