Effects of Sb and Zn Addition on Mechanical Properties and Corrosion Resistance of Sn-Ag-Cu Solders

摘要

Pb-free solders have been widely developed by materials researchers as mainly focused on the replacement for Sn-Pb eutectic solder. In this study, Sn-3.0Ag-0.5Cu, Sn-3.0Ag-0.5Cu-xSb and Sn-3.0Ag-0.5Cu-xZn solders (x = 1.0, 2.0 and 3.0 wt%) were prepared using melting method. The effect of Sb and Zn addition on microstructure and properties, such as tensile strength, microhardness and corrosion resistance of Sn-Ag-Cu solders was investigated. The microstructure analysis revealed that addition of Sb and Zn to the Sn-Ag-Cu solders obviously decreased phase fraction of the dendritic β-Sn phase and the finer eutectic phase was obtained, resulting in superior mechanical properties of the Sn-3.0Ag-0.5Cu-xSb and Sn-3.0Ag-0.5Cu-xZn solders compared to the Sn-3.0Ag-0.5Cu solder. The results of potentiodynamic polarization tests indicated that the corrosion potentials of the Sn-3.0Ag-0.5Cu-xSb solders continuously increased with increasing of Sb content. While Zn content had little effect on the corrosion potentials of the Sn-3.0Ag-0.5Cu-xZn solders.