Corrosion characterization of tin–lead and lead-free solders in 3.5 wt.% NaCl solution
The corrosion resistance of Sn-Pb and several candidate lead free solders were investigated in 3.5wt.% NaCl solution through potentiodynamic polarisation. Results showed that in NaCl solution lead free solders had better corrosion resistance than Sn- Pb solder and the corrosion resistance of lead free solders was similar, but the corrosion resistance of Sn-Ag solder was better than that of Sn-Ag-Cu and Sn-Cu solders. The corrosion products for Sn-Pb solder had a two-layered structure with Sn-rich phases at the outer layer and looser Pb-rich phases at the inner layer. The loose Pb-rich layer was detrimental to the corrosion property. The corrosion product on the surface of all these solders was tin oxide chloride hydroxide.
- Mechanical, Electrical and Manufacturing Engineering