| Silver-flo™ 452 is a cadmium free silver brazing filler metal. It exhibits a comparatively low brazing temperature with a short melting range. Silver-flo™452 is relatively free flowing and produces neat joints with small fillets. This filler metal has been used for brazing of PCD segments in tool applications. In these cases the brazing temperature has successfully been kept below the point at which the PCD begins to degrade. It should be noted that this filler metal contains tin and may be described as being ‘hot-short’. It should not be quenched from high temperatures (in excess of 300°C) and care should be taken when it is used to braze components with widely differing coefficients of thermal expansion as in both cases cracking of the joints may occur. Silver-flo 452™ is recommended where the presence of silicon is not desirable. This alloy is suitable for seawater applications, being resistant to dezincification. This filler metal can be used to join all the common engineering materials (excluding aluminum) – such as copper, copper alloys (including, brasses, bronzes, gun metal, nickel silvers, aluminum bronze, copper nickel) and steel (including, mild, carbon, tool steel, stainless steels and low alloy steel). It may be used for brazing tungsten carbide and PCD segments however where cracking of the carbide or wetting of the filler metal may be an issue specialized silver brazing filler metals containing nickel / manganese are often preferred. Information provided by Johnson Matthey Metal Joining |
