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 Cu3Sn were Sn3O(OH)2Cl2, CuCl, and co-existing phases CuCl and Sn3O(OH)2Cl2, respectively. In addition, the SnO2, Sn3O(OH)2Cl2, Cu2O, and CuCl2·3Cu(OH)2CuCl2·3Cu(OH)2 were observed in the Cu6Sn5 phase.

► Corrosion behavior of the Cu6Sn5, Cu3Sn, and compares to that of pure Cu and Sn. ► Both galvanic corrosion and potentiodynamic polarization methods was performed using a 3.5 wt.% NaCl solution. ► Experimental evidences illustrating Cu content affects the corrosion behavior of Cu–Sn IMC.