Abstract This study investigates microstructures and mechanical properties of the alloys obtained by adding Cu (0.7 % and 0.9 %) and Al (0.7 % and 0.9 %) to lead-free Sn-9Zn eutectic soldering alloy produced by investment casting method. The results show that Cu5Zn8 phase has formed in the structure of Cu added alloys and the Al2O3 phase has formed due to addition of Al. It was found that small and round-shaped Al2O3 phase increased the tensile strength of the new alloy compared to the eutectic alloy. In addition, it was observed that the microhardness of Cu added alloys was lower than that of Sn-9Zn eutectic alloy, but the microhardness of alloys containing Al was higher compared to the other eutectic Sn-9Zn alloy.

中文翻译：

---

Sn-9Zn-xAl和Sn-9Zn-xCu无铅焊料合金的组织和力学性能

摘要 本研究研究了在熔模铸造法生产的无铅Sn-9Zn共晶钎料中添加Cu（0.7%和0.9%）和Al（0.7%和0.9%）获得的合金的显微组织和力学性能。结果表明，Cu添加合金的组织中形成了Cu5Zn8相，Al的添加形成了Al2O3相。结果表明，与共晶合金相比，小而圆形的 Al2O3 相提高了新合金的抗拉强度。此外，观察到添加Cu合金的显微硬度低于Sn-9Zn共晶合金，但与其他共晶Sn-9Zn合金相比，含Al合金的显微硬度更高。