Corrosion resistance of Zr-based bulk amorphous alloys containing Pd

The structure, thermal stability and corrosion resistance of the bulk amorphous Zr55Al10Cu30Ni5-xPdx (x=0, 1, 3, 5 at.%) alloys were studied by X-ray diffraction (XRD), high-resolution transmission electron microscope (HRTEM), differential scanning calorimetry (DSC) and electrochemical measurements, respectively. The Zr-based alloys containing 0 and 1% Pd both show an active-passive transition by anodic polarization in 0.6 M NaCl solution, while the 3 and 5% Pd modified amorphous alloys show a single active state with pseudo passivation phenomenon. The results of XPS and HRTEM reveal that the microstructure seriously affects the corrosion behaviors of the bulk Zr-based alloys in 0.6 M NaCl. The mixture state of amorphous and nanocrystal phases leads to the deterioration of the corrosion resistance