Comparative study on corrosion of SN-37PB, SN-3.5AG and SN-9ZN solders in acidic environment

The corrosion behaviour of Sn-37Pb, Sn-3.5Ag and Sn9Zn solder alloys in hydrochloric acid and sulphuric acid solutions has been studied over a range of acid concentrations by Tafel Extrapolation electrochemical technique. The study revealed that the corrosion rates of different alloys increase with the increase in concentration of sulphuric and hydrochloric acid media. The corrosion resistance of lead based solder was found to be superior to lead-free solders in the acidic environments investigated. Significantly higher corrosion current density and corrosion rates were observed with lead-free solders.