Electrochemical Properties of Porous Pd-Based Bulk Metallic Glasses

Abstract

The corrosion behavior of porous Pd_42.5Cu₃₀Ni_7.5P₂₀ bulk metallic glasses with various porosities in Hanks’ solution was investigated. The results revealed that all bulk metallic glasses exhibited similar corrosion behavior. The bulk metallic glasses with the porosity of 0 and 18% were spontaneously passivated with passive current densities between 10⁻² and 10⁻¹ A/m² in anodic polarization curves. The bulk metallic glasses with 40 and 55% porosity exhibited an anodic process with the current density increasing gradually. As the anodic potential increasing, no obvious passivity breakdown occurred in the anodic polarization process. The polarization resistance decreased with the increasing of the porosity from 0 to 55%. The breakdown potential of the passive film for the bulk metallic glass with 55% porosity was about 100 mV lower than that of the 0% porosity Pd_42.5Cu₃₀Ni_7.5P₂₀ bulk metallic glass.