The corrosion and oxidation behavior of Zr-based metallic glasses

Zr-based bulk metallic glasses are promising engineering materials due to their good glass-forming abilities and unique combination of good strength (similar to 1.9 GPa) and medium stiffness. In this study, the corrosion behaviors of Zr-Co-Al-Ag BMGs, with silver content from 0 to 11 at.%, in NaCl and H2SO4 solutions were investigated. The corrosion resistance increased when the silver content increased. The oxidation behaviors of Zr-Co-Al-Ag BMGs were also studied. The oxidation kinetics of all the samples obeyed a two-stage parabolic rate law, which consisted of an initial transient oxidation followed by a steady-state oxidation stage. The addition of Ag was found to reduce the oxidation resistance of Zr-Co-Al-Ag BMGs. Some white nodules, possibly cobalt oxide, were observed when the Zr-Co-Al-Ag BMG with 8 at.% Ag was oxidized at high temperature.