Corrosion Resistance and Electrochemical Behaviour of Amorphous Ni84.9Cr7.4Si4.2Fe3.5 Alloy in Alkaline and Acidic Solutions

In this work, the corrosion behaviours of the amorphous Ni84.9Cr7.4Si4.2Fe3.5 alloy and its crystalline counterpart are studied in acidic, neutral, and alkaline solutions by scanning electron microscopy, electrochemical impedance spectroscopy, and potentiodynamic and potentiostatic polarization tests. X-ray photoelectron spectroscopy and scanning Kelvin probe are employed to characterize the alloy surface. The results show that the amorphous Ni84.9Cr7.4Si4.2Fe3.5 alloy presents a better corrosion resistance compared to its crystalline counterpart, which is attributed to the uniform energy distribution of the atoms on the amorphous alloy surface, and this presents as a uniform electric potential map to effectively suppress the occurrence of the corrosion cell reaction.