( 大连理工大学 材料工程系， 大连 116023)
摘 要: 采用ST50润湿实验仪完成了钎焊并研究分析了Sn-9Zn-3Bi/Cu 接头在170℃下长期时效的显微结构变化。 结果表明： Sn-9Zn-3Bi/Cn接头时效至200h后在界面处形成单一连续的Cu5Zn8化合物层；时效至500h和1000h后， 界面处形成了3层化合物层， 从铜母材侧起， 分别为Cu-Sn化合物层， Cu-Zn化合物层和Sn-Cu化合物层； 随着时效时间的增加， 整个金属化合物层变厚，而Cu-Zn化合物层减薄， 表明Cu-Zn化合物层在时效过程中具有不稳定性。
关键字: 无铅钎料； Sn-Zn-Bi；显微结构； 界面反应； 金属间化合物
（ Department of Materials Engineering,
Dalian University of Technology, Dalian 116023, China）
Abstract: Soldering process was performed by wetting test machine ST50. The microstructures of Sn-9Zn-3Bi/Cu joint were investigated under 170℃ thermal exposure conditions. The results show that a continuous single layer of Cu5Zn8 intermetallic compound appears when aging within 200h and three layers are formed after aging for 500h and 1000h. From the Cu substrate, they are Cu-Sn layer, Cu-Zn layer, Sn-Cu layer, respectively. The total intermetallic compound layers thicken while the thickness of Cu-Zn compound layer decreases with increasing exposure time. It indicates that the Cu-Zn compounds are not stable during long-term aging.
Key words: lead-free solder; Sn-Zn-Bi; microstructure; interface reaction; intermetallic compound
