Vacuum brazing alloys refer to solders used for vacuum brazing or brazing alloys served under vacuum conditions. Such brazing processes are often carried in vacuum furnace, and brazing flux is not needed. The most widely used vacuum solders are silver vacuum brazing alloys, as they have appropriate melting point, good conductivity, high mechanical strength and plasticity. They also have high corrosion resistance in various kinds of medium. Silver vacuum brazing alloys can be used for the brazing of nickel-plated ceramic, stainless steel, titanium alloy, copper alloy and other materials.