Glass-forming Ability and Corrosion Resistance of ZrCuAlCo Bulk Metallic Glass

Investigations were carried out to examine the effects of Co addition on the glass-forming ability (GFA) and corrosion resistance of Zr46Cu46Al8 bulk metallic glass in chloride-containing solution. It is found that the GFA of (Zr46Cu46Al8)100−xCox (x = 0, 1, 2, and 4 at.%) alloys reduces with the increase in Co content and correlates well with the parameters, such as the supercooled liquid region width ΔTx, the reduced glass transition temperature Trg and γ. The corrosion resistance is however found to be enhanced with the increase in Co concentration. The addition of Co causes the enrichment of Zr and Al, but depletes Cu in the surface films, which effectively enhances the corrosion potential and lowers the corrosion current density.