Corrosion behavior of as-cast ZK60 alloy modified with rare earth addition in sodium sulfate medium

The corrosion resistance of the as-cast ZK60 alloy with and without 1.5 %wt rare earth (RE) addition and submitted to a dip sol-gel coating was investigated using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) in 0.1 mol/L Na2SO4 solution. Analysis using scanning Kelvin probe force microscopy (SKPFM) was carried out to investigate the corrosion attack mechanism on these alloys. The RE addition has accelerated the ZK60 alloy dissolution by formation of a less noble RE-rich second phase. The dip sol-gel coating was not confirmed as a powerful tool to enhance the protection against corrosion in the as-cast ZK60 alloys.