Effect of the pH on the Corrosion Behaviour for a Ni_59.5 Nb_40.5 Binary Metallic Glass

Abstract

Ni-Nb binary metallic glass was synthesized by the melt spinning technique with a tangential wheel rotation speed during cooling of 6 m/s obtaining a glassy matrix which was characterized by X-ray diffraction (XRD). Electrochemical properties were determined by electrochemical impedance spectroscopy (EIS). The results show that this metallic glass is very resistant to corrosion, being better when exposed to corrosive media with pH = 0 and 7 in chloride ions presence. However, at pH = 14 the passive film is not homogeneous, and the corrosion rate increases with respect to the other systems.

Improving the Corrosion Resistance of NiNb-Based Bulk Metallic Glass through the Hot Compression

“…Several processes such as annealing, microalloying, and thermomechanical treatments have been carried out to improve the corrosion resistance of Ni-based BMGs as much as possible. For instance, Espinoza Vazquez et al [9] reported that NiNb amorphous alloy exhibited a superior corrosion resistance under the presence of chloride ions when the pH value was in the range of 0-7. On the other hand, the passive flm got inhomogeneous, and the corrosion rate increased at pH � 14.…”