Abstract:In this experiment selected SnPb, InPb and InPbAg three solders were selected to solder the AuNi9
brush wires which serve in the spacecraft control system. The mechanical properties, the fracture morphology, microstructures
and the composition of compound phases of soldered joints were compared, thus exploring the impact of the
improved solder on the formation of the compound layer in soldered joints. The results show that there generate the obvious
compounds in AuNi9 soldered joints near the gold alloy side using SnPb solder, mainly including AuSn4, Au-
Ni2 Sn4 and Ni3Sn4 compound phases. InPb solder can significantly reduce the joints brittleness, and there generate no
intermetallic compounds in the joint region. While the InPbAg solder can not only protect the silver layer of copper
wires, but also could produce the tiny strengthening phase, i. e. , Ag2In in the joint to enhance the joint shear
strength.
