Corrosion characterization of Cu―Sn intermetallics in 3.5 wt.% NaCl solution

The corrosion behavior of Cu-Sn intermetallics was investigated in 3.5 wt.% NaCl solutions and compared to that of Cu and Sn by using galvanic corrosion and polarization methods. Polarization curves showed that an increase in the Cu content increased the corrosion current density and shifted both corrosion potential and breakdown potential towards more noble values. The corrosion products on the surface of Sn, Cu and Cu sub(3)Sn were Sn sub(3)O(OH) sub(2)Cl sub(2), CuCl, and co-existing phases CuCl and Sn sub(3)O(OH) sub(2)Cl sub(2), respectively. In addition, the SnO sub(2), Sn sub(3)O(OH) sub(2)Cl sub(2), Cu sub(2)O, and CuCl sub(2) times sub(3)Cu(OH) sub(2) were observed in the Cu sub(6)Sn sub(5) phase.