The shear strength of copper and brass soldered with Sn-40% Pb containing 0 to 10% Sb and/or 0 to 15% Zn

Abstract

The single lap shear strength of copper and brass soldered with Sn-40% Pb containing 0 to 10% Sb and/or 0 to 15% Zn has been determined and the microstructure examined using metallographic techniques. For any solder composition, brass joints were stronger than copper joints. The strength of copper joints decreased monotonically with the increase of antimony in Sn-Pb solder, and the strength of brass joints increased to a peak with about 3% Sb in the solder and thereafter decreased on further additions of antimony. With less than a few per cent antimony in the solder, 1 % Zn in the solder decreased the strength of both copper and brass joints; with more than 1 % Zn in the solder the strengths of both copper and brass joints were increased substantially. Fracture occurs mainly in the Cu6Sn5. The microstructure and the presence of zinc in the intermetallic compounds were determined, and the results are discussed.