Atmospheric corrosion of tin coating on T2 copper in Xiangtan, China

Abstract

Atmospheric corrosion of tin coating on copper was explored to understand the differences in corrosion behavior between the skyward and earthward surfaces of the tin coating. Results show that average corrosion rate of the tin coating was 0.578 ± 0.051 and 1.137 ± 0.166 µm·y⁻¹ after one year and two years of exposure in Xiangtan, China, respectively. Corrosion rate of the tin coating during the second year of exposure was higher than that during the first year. SnO₂ was the main corrosion product of the tin coating. Localized corrosion vulnerabilty of the skyward surface was higher than that of the earthward surface during the first year of exposure, but it became lower than the latter during the second year. During the first year of exposure, i_corr values of the skyward and earthward surfaces were relatively low, but they sharply increased during the second year of exposure.