Microstructure and solderability of Sn-9Zn-xCe lead-free solder

Effects of rare earth element Ce added in Sn-9Zn solder on the microstructure and spreading property as well as mechanical properties were investigated. Results indicate that with the increase of the Ce from 0 to 0.08%,the microstructure is refined obviously and Zn-rich phrase is decreased. While the content of Ce exceeds 0.08%,small block Sn-Ce intermetallic compounds will appear. Results also show that with the increase of the Ce,the spreading property is improved,the spreading areas reaches maximum when the content of Ce is up to 0.08%,and the best mechanical properties of the soldered joints are achieved while the content of Ce is about 0.08%.