Electrochemical and surface investigation of zirconium based metallic glass Zr59Ti3Cu20Al10Ni8 alloy in nitric acid and sodium chloride media

To understand the corrosion behavior of zirconium based bulk metallic glass (BMG); electrochemical, and surface investigations were carried out on Zr59Ti3Cu20Al10Ni8 alloy in HNO3 acid, and NaCl medium. Electrochemical studies were carried out in 1 N, 6 N and 11.5 N HNO3 by recording open circuit potential-time, potentiodynamic polarization, and impedance characteristics. Atomic force microscope was used for ex situ surface morphology study of the specimens after potentiodynamic polarization in 1 N, 6 N, and 11.5 N HNO3, and in situ surface morphology study by free immersion of the specimens in both 0.5 M, and 1 M NaCl solution. The results revealed attaining of steady state noble open circuit potential, wider passive region, and decrease in transpassive potential (Etranspass) with increase in HNO3 concentration. Surface morphology in free immersion, and after polarization showed, deep pit propagation in both 0.5 M, and 1 M NaCl solution, and aggressive surface dissolution in HNO3 medium.