Electrochemical Migration behavior of Sn9Zn

In this paper, the electrochemical migration behavior of Sn9Zn was studied by water drop experiment. The results show that the occurrence of electrochemical migration was accompanied by the formation of metal deposits, when metal deposits formed at cathode were grown to anode, a " bridge " was formed between two electrodes and caused short circuit. The morphology of Sn9Zn metal deposits were relatively thick and mainly composed of Sn, SnO
₂
, SnO, Zn and ZnO. Part of the metal ions dissolved in the anode will form metal deposits, and some will participate in the formation of precipitates, the precipitates components were mainly hydroxides of Sn or Zn, but they were unstable in the air, and they will form the corresponding oxides after dehydration. With the increases of voltage, the short circuit failure time of electrochemical migration of Sn9Zn decreases gradually. Taking t=aV
^b
as the fitting equation, the curve of Sn9Zn between electrochemical migration short circuit failure time and voltage was fitted to t=2456.87*U
^-2.7872
, and the critical failure voltage for electrochemical migration of Sn9Zn was calculated to be 1.194V. When NaCl solution was used as the electrolyte, at a lower voltage, the anode surface corrosion pits after electrochemical migration of Sn9Zn were shallower and evenly distributed, and no lamellar structures were formed; However, at a high voltage, there were lamellar structures on the surface of Sn9Zn anode after electrochemical migration, and its main composition was Zn
₅
(OH)
₈
Cl
₂
. H
₂
O. In the condition of electric field or bubble stirring, it was very easy to fall off and promote further dissolution of the anode. It can promote the occurrence of electrochemical migration phenomenon, so at a higher voltage, the anti-electrochemical migration performance of Sn9Zn decresed seriously.