Effect of oxygen impurity on corrosion behavior of a Zr-based bulk metallic glass in 0.5 M H2SO4 and 0.5 M NaOH solutions.

• Effect of oxygen impurity on corrosion of a Zr-based BMG in H 2 SO 4 and NaOH is studied. • Oxygen impurity has no effects on the corrosion in 0.5 M H 2 SO 4. • Oxygen impurity can improve the corrosion resistance in 0.5 M NaOH. • Oxygen-induced annihilation of free volume may account for the inhibited corrosion. Effects of unavoidable oxygen impurity in industrial-grade Zr-based bulk metallic glasses (BMGs) on their properties are the issues that must be considered. The studies on oxygen-related corrosion behaviors of Zr-based BMGs are rarely reported. This paper aims to clarify the effects of oxygen impurity on corrosion of the as-cast Zr 61 Ti 2 Cu 25 Al 12 BMGs in 0.5 M H 2 SO 4 and 0.5 M NaOH solutions. The results show that oxygen impurity has no effects on the corrosion in 0.5 M H 2 SO 4 , but is unexpectedly beneficial for improving the corrosion resistance in 0.5 M NaOH by inhibiting the cathodic reaction. The latter phenomenon could be correlated with the oxygen-induced annihilation of free volume. The finding herein further confirms that oxygen impurity is not harmful, even beneficial, for corrosion resistance of industrial-grade Zr 61 Ti 2 Cu 25 Al 12 BMGs. [ABSTRACT FROM AUTHOR]