Evaluation of corrosion behaviour of a new class of Pb-free solder materials (Sn-In-Zn)

In view of the need fur a lead-free drop in replacement for the widely used 40Pb-60Sn near eutectic solder, new Sn-In-Zn based alloys with substantial ly the same melting point have been developed. The corrosion resistance and the influence of zinc content on electrochemical behaviour of some special alloys Sn-In-Zn in 3% NaCl solution has been investigated using electroche mical techniques. The good resistance of this ternary system is confirmed. In decreasing dissolution rate, they are ranked as follows: 40Pb-60Sn, Sn-1 0.6In-27Zn, Sn-11In-23Zn and Sn-13In-12Zn. The increase of zinc content ind uces a decrease of corrosion resistance of ternary Sn-In-Zn alloys. So, the Sn-In-Zn system with low indium and zinc concentrations might be a good ca ndidate for solder materials and present a good corrosion resistance.