Ti addition to enhance corrosion resistance of Sn-Zn solder alloy by tailoring microstructure

摘要

The effect of trace addition of Ti on the corrosion behavior of Sn-9Zn (wt.%) solder alloy in NaCl solution was investigated using polarization and electrochemical impedance spectroscopy techniques. It is found that the corrosion resistance of Sn-9Zn alloy can be significantly enhanced by adding 0.05 wt.% of Ti, evidenced by much lower corrosion current density, lower passive current density and higher impedance. Such enhancement results from the refinement of Zn-rich precipitates within the microstructure, which is conducive to forming a relatively more protective passive film on the surface of the modified alloy. This would be an important finding in the design of novel Sn-Zn solder alloys in electronic assemblies operating under aggressive conditions. (C) 2015 Elsevier B.V. All rights reserved.