中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 33 No. 6 June 2023 |
（1. School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China;
2. State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures, Nanning 530004, China;
3. MOE Key Laboratory of New Processing Technology for Nonferrous Metals and Materials, Nanning 530004, China）
Abstract:The corrosion behaviors of Sn-20Bi-xCu-yIn (x=0.3, 0.5 wt.%; y=1, 2, 3 wt.%) in 3.5 wt.% NaCl solution at room temperature were investigated. Electrochemical impedance spectroscopy (EIS) plots, potentiodynamic polarization curves, and corroded surface product characterization were used to evaluate the corrosion resistance of the solders. Analysis of EIS and polarization curves shows that the corrosion resistance of the solders decreases as the In and Cu contents increase. Scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy were applied to characterizing the corrosion product. It is found that the corrosion product is Sn3O(OH)2Cl2, which cannot play a protective role because of its loose structure. Sn-20Bi-0.3Cu-1In has the best corrosion resistance.
Key words: lead-free solder; corrosion behavior; electrochemical impedance spectroscopy; polarization curve; Sn3O(OH)2Cl2
