Effect of alloying elements on microstructure and property of AgCuZnSn brazing alloy

The Sn, Ni, P were added into AgCuZnSn brazing alloy.And the effects of Sn, Ni and P on the microstructure and property of AgCuZn cadmium-free brazing alloy system were investigated.The results showed that the wettability of the brazing alloy was improved with the addition of Sn.The addition of P could decrease the interfacial tension between liquid brazing alloy and specimen, and the wettability and fluidity were also improved.The microstructure of AgCuZn brazing alloy was consisted of Cu-rich phase, CuZn intermetallic compound, Cu_5.6 Sn intermetallic compound, Cu_40.5Sn₁₁ intermetallic compound and Ag-rich phase.Dendrite that formed in the alloy microstructure make brazing alloy friable after the addition of Sn.The black Ni₃ P compound was generated when Ni was added, and make microstructure homogeneous.The gray Cu₃ P compound was generated when P was added.