Influence of Ni on microstructure and processing performance of Ag-Cu-Sn-In brazing alloy

Influence of Ni on the microstructure and processing performance of Ag-Cu-Sn-In brazing alloy was investigated. The microstructures of Ag-Cu-Sn-In of solder were composed of β-Cu coarse dendrite,(α-Ag) distributing in the interdendritic space and little Ag₅Sn. By adding Ni element,the grains refined,the melting point rised a little,and processability was influenced evidently. With Ni content increasing,rate of deformation is bigger,processability of brazing alloy is better. As Ni content was 0.2%,the rate of deformation reached maxinum. Ni content sequentially increasing,microstructures of brazing alloy are becoming bulkily,and processability is worse. With 0.2% Ni Content,the temperature of solidus and liquidus of alloy foils increased respectively by 18℃ and 8℃,the temperature interval decreased by 20℃. After annealing treatment,brazing alloy with 0.2% Ni can be rolled into foils of 50~80μm thickness.