Thermal Stability of Electroplated Equiatomic Tin-Nickel Alloy: Microstructure and Electrochemical Properties

摘要

Electroplated equiatomic Sn-Ni coatings have recently found widespread use in various applications for their good passivation ability. It is generally accepted that the obtained Sn-Ni coatings are single phase and metastable in nature. However, the exact nature of this metastable electrodeposit is still debated. The passivation properties and ease of electrodeposition of the Sn-Ni system makes it useful not only as a free standing corrosion protection coating but also in multi-coating systems where a corrosion resistant layer is required below a functional coating. For applications involving low power electrical contacts the Sn-Ni coating find potential use as a passivating interlayer with a wear resistant outer layer obtained using PVD. PVD processes usually run in the temperature range of 100-300 °C, and this poses a challenge for the metastable Sn-Ni.