Silver-flo™ 43 is a cadmium free silver brazing alloy. It is not a commonly used or specified alloy. However, it was originally developed by Johnson Matthey in research to find a low silver content filler metal alloy that is resistant to dezincification in marine environments. As such this alloy is suitable for seawater applications, and is still used in some naval or marine work where written specifications call for it. Silver-flo™ 43 has a brazing temperature that is above the annealing or stress relieving temperature of many copper-nickel alloys. Consequently Silver-flo™ 43 has been used on cupro-nickel and high nickel content copper alloys where stress cracking / intergranular penetration may otherwise be a problem. Silver-flo™ 43 has a relatively long melting range, is not free flowing and will fill joint gaps at brazing temperature of between 0.075-0.2mm. It can therefore be used for filling joints that cannot be tightly controlled. 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). Information provided by Johnson Matthey Metal Joining |