Effects of Crystallization on the Corrosion and Passivity of Amorphous Pd-Fe-Co-Si-B Alloys

Abstract

Corrosion behavior of Pd48.2Fe17Co16.7Si13.4B4.7 and Pd51.4Fe18Co18Si11.1B1.5 alloys was examined by potentiodynamic polarization tests in pH 8.5 buffer solution. The amorphous alloy ribbons showed passivity with the passive current densities of 2 × 10−6 A/cm2~4 × 10−6 A/cm2. The crystalline alloys showed a higher corrosion rate in pH 8.5 buffer solution with the degree of variation depending on the alloy composition. It is suggested from the Mott-Schottky analysis that the donor density was lower for the amorphous alloy than the crystalline alloy.