Electrochemical corrosion behavior of CeO2 nanoparticle reinforced Sn–Ag based lead free nanocomposite solders in 3.5 wt.% NaCl bath

• An optimum amount of nano ceria in Sn–3.5Ag matrix improves the corrosion resistance.
• Well dispersed ceria nanoparticles prevent the localized matrix corrosion.
• Presence of finer Ag3Sn increases the passivation of the solder matrix significantly.

The corrosion behavior of lead free Sn–3.5Ag and Sn–3.5Ag alloy reinforced with different amounts of CeO2 nanoparticles is investigated in 3.5 wt.% NaCl solution. Polarization and electrochemical impedance studies reveal that the corrosion current density (icorr), the corrosion potential (Ecorr), and double layer capacitance (Cdl) decrease, while the charge transfer (Rct)/polarization resistance (Rp) increase with the incorporation of CeO2 nanoparticles (up to an optimum of ~ 12 wt.% of CeO2 nanoparticles). The corrosion product, SnCl2 is detected on the surface of Sn–Ag alloy which is coarse and loosely adherent to the surface, while Sn–Ag/CeO2 possess finer corrosion products intact to the surface and thus increases passivity.