Tsurusaki Tatsuya, Ohgai Takeshi
Graduate School of Engineering, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan.
Faculty of Engineering, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan.
Materials (Basel). 2020 Mar 14;13(6):1330. doi: 10.3390/ma13061330.
Enforced solid solution type Sn-Zn alloy films were electrochemically synthesized on Cu substrate from an aqueous solution containing citric acid complexes. The electrodeposition behavior of Sn-Zn alloys was classified to a normal co-deposition type, in which electrochemically nobler Sn deposits preferentially compared to Zn. Electrodeposited Sn-Zn alloy films were composed of a non-equilibrium phase, like an enforced solid solution, which was not observed in an equilibrium phase diagram of an Sn-Zn binary alloy system. By applying a thermal annealing process at 150 °C for 10 minutes, a pure Zn phase was precipitated from an electrodeposited Sn-based solid solution phase with excessively dissolved Zn atoms. During the soldering process, intermetallic phases such as CuSn and CuZn were formed at the interface between an Sn-Zn alloy and Cu substrate. Tensile strength and fracture elongation of solder-jointed Cu rods with Sn-8 at.%Zn alloy films reached ca. 40 MPa and 12%, respectively.
通过电化学方法，在含有柠檬酸络合物的水溶液中，于铜基底上合成了强制固溶体型Sn-Zn合金薄膜。Sn-Zn合金的电沉积行为属于正常共沉积类型，其中电化学性质较惰性的Sn比Zn更优先沉积。电沉积的Sn-Zn合金薄膜由非平衡相组成，类似于强制固溶体，这在Sn-Zn二元合金体系的平衡相图中并未观察到。通过在150℃下进行10分钟的热退火处理，从电沉积的含过量溶解Zn原子的Sn基固溶相中析出了纯Zn相。在焊接过程中，在Sn-Zn合金与铜基底的界面处形成了诸如CuSn和CuZn之类的金属间相。具有Sn-8原子%Zn合金薄膜的焊接铜棒的拉伸强度和断裂伸长率分别达到约40MPa和12%。
