Effect of Cu and Ni Addition on Microstructure and Wettability of Sn-Zn Solders

摘要

In present study, Sn-9Zn, Sn-9Zn-xCu and Sn-9Zn-xNi solders (x = 0.1, 0.5 and 1.0 wt%) were prepared via melting process. Effects of Cu and Ni addition on microstructure, thermal behavior, wettability and corrosion resistance of Sn-9Zn solders were investigated. The experimental result showed that microstructure of the Sn-9Zn was composed of β-Sn and Zn-rich phases. The Cu_6Sn_6 and Cu_5Zn_8 IMCs were found when addition of Cu. While addition of Ni to the Sn-9Zn solders resulted in the formation of the Ni_3Sn_4 and Ni_5Zn_(21) IMCs. It was also found that, amount of those IMCs obviously increased with increasing of Cu and Ni contents. The results obtained from thermal analysis showed that melting temperature of the Sn-9Zn solder was 199.6°C. While melting temperatures of the Sn-9Zn-1.0Cu and Sn-9Zn-1.0Ni solders were 199.9°C and 204.2°C, respectively. The Cu and Ni contents had little effect on both spread rate and wetting angle of the Sn-9Zn-xCu and Sn-9Zn-xNi solders. However, increasing of Cu and Ni contents significantly increased the corrosion potentials of the Sn-9Zn-xCu and Sn-9Zn-xNi solders.