Passive film properties and corrosion behavior of Ni–Nb and Ni–Nb–Ta amorphous ribbons in nitric acid and fluorinated nitric acid environments

摘要: Abstract Potentiodynamic polarization and electrochemical impedance studies revealed the passivation ability corrosion resistance of Ni60Nb40 Ni60Nb30Ta10 amorphous ribbons in 11.5 M HNO3 HNO3 + 0.05 M NaF media at room temperature. Mott–Schottky analysis indicated formation n-type semiconducting passive film on these ribbon samples. Electrochemical parameters such as current density, density donor confirmed property to be superior that ribbon. Weight loss was insignificant exposed boiling for 240 h. XPS origin passivity due a relatively thick ≈3 nm enriched with Nb2O5 thin ≈1.5 nm both Ta2O5 respective ribbon's surface. In fluorinated nitric acid, underwent severe dissolution owing instability Nb-oxide oxide/metal interface.