Selective dissolution sensitive to minor alloying in CuZr-based metallic glasses

•The selective dissolution of CuZr-rich glasses is sensitive to minor Ni additions.•Surface corrosion layers vary in composition from a Cu-enriched film to a Zr-enriched film.•The preferential dissolution of Zr atoms is inhibited by minor Ni alloying.•The switchable selective dissolution is controlled by local atomic interactions.

The selective dissolution behaviour of CuZr-based metallic glasses can be strongly influenced by minor Ni additions. The surface corrosion layers of the Ni-free alloy are changed from a porous Cu-enriched film to a Zr-enriched covered passive film on the Ni-containing alloys, thus, resulting in the elevation of critical potentials. The results indicate that the preferential dissolution of Zr atoms is inhibited by minor Ni alloying, while Cu atoms dissolve. A local bonding controlled mechanism is proposed to understand the switchable behaviour of selective dissolution. It presents us with new insights into the intrinsic corrosion resistance of alloys.